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• abort, terminate or exit?

  - by Knowing me knowing you

  What's the difference between those three, and how shall I end program in case of exception which I can't handle properly?

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• java.util.EmptyStackException on JIT/Warmup

  - by infectedrhythms

  I'm using a 3rd party lib in my application that throws a java.util.EmptyStackException This only happens during the VM JIT/Warmup Start application Start stress test no rampup. java.util.EmptyStackException thrown Keep application and redo stress test. No exception thrown Shutdown application Start application Start stress test with rampup. No exception thrown I could keep reproducing this over and over. Anyone have any ideas on how I can trace this so I can give more info to the vendor? Or why it could even be happening? Thanks

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• Is this a valid code in C++

  - by VVV

  class Exc1 extends Exception { void println() { System.out.println("Exc1"); } }

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• Help with my application please! Can’t open image(s) with error: External component has thrown an ex

  - by Brandon

  I have an application written in C# I believe and it adds images to a SQL Server 2005 Database. It requires .NET 3.5 to be installed on my computer. I installed .NET 3.5 and setup a database. It runs fine but then once it gets to image 100 when running on one computer, It stops and gives me this error: Can't open image(s) with error: External component has thrown an exception.... When I run the program on my own computer I am able to reach 300 images but then it stops after 300 images and gives me Can't open image(s) with error: External component has thrown an exception.... error once again. please help!

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• Warning that users must handle

  - by hagaik

  I am looking for a way to set warning that the user will have to respond. In a sense I would like to use late exception mechanize that occur after the function already finished executing.and returned the wanted value. SomeObject Foo(int input) { SomeObject result; // do something. oh, we need to warn the user. return result; } void Main() { SomeObject object; object = Foo(1); // after copy consturctor is done I would like an exception to be thrown }

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• NullPointerException

  - by Knowing me knowing you

  Why do I get exception called NullPointerException if in Java there is no such concept as a pointer? Thanks

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• Default http/admin port in dropwizard project

  - by mithrandir

  I have a dropwizard project and I have maintained a config.yml file at the ROOT of the project (basically at the same level as pom.xml). Here I have specified the HTTP port to be used as follows: http: port:9090 adminPort:9091 I have the following code in my TestService.java file public class TestService extends Service<TestConfiguration> { @Override public void initialize(Bootstrap<TestConfiguration> bootstrap) { bootstrap.setName("test"); } @Override public void run(TestConfiguration config, Environment env) throws Exception { // initialize some resources here.. } public static void main(String[] args) throws Exception { new TestService().run(new String[] { "server" }); } } I expect the config.yml file to be used to determine the HTTP port. However the app always seems to start with the default ports 8080 and 8081. Also note that I am running this from eclipse. Any insights as to what am I doing wrong here ?

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• Problem: scrolling a tableview and then select the searchbar (iphone)

  - by Samui

  Hello everyone, I've been stuck with this problem for hours and I can't see the light. Please give me a hand with this: I have a tableview and a searchbar. The searchbar is situated in the navigationbar. When I do a fast scroll of the tableview, if I select the searchbar while the tableview is still decelerating, a exception raises: Terminating app due to uncaught exception 'NSRangeException', reason: ' -[NSMutableArray objectAtIndex:]: index 31 beyond bounds for empty array' How can I stop programmatically the deceleration of the tableview? Thanks for your time!

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• Can't start managed server in Oracle Weblogic 10.3.2

  - by Neuquino

  I installed Oracle SOA Suite 11g. I start the NodeManager successfully. I start the AdminServer successfully. When I go to start the soa serve (soa_server1) I get this output: NMProcess: <Mar 15, 2010 3:33:30 PM> <WARNING> <Exception while starting server 'soa_server1'> NMProcess: java.io.IOException: Server failed to start up. See server output log for more details. NMProcess: at weblogic.nodemanager.server.ServerManager.start(ServerManager.java:331) NMProcess: at weblogic.nodemanager.server.Handler.handleStart(Handler.java:541) NMProcess: at weblogic.nodemanager.server.Handler.handleCommand(Handler.java:116) NMProcess: at weblogic.nodemanager.server.Handler.run(Handler.java:70) NMProcess: at java.lang.Thread.run(Thread.java:619) NMProcess: NMProcess: Mar 15, 2010 3:33:30 PM weblogic.nodemanager.server.Handler handleStart NMProcess: WARNING: Exception while starting server 'soa_server1' NMProcess: java.io.IOException: Server failed to start up. See server output log for more details. NMProcess: at weblogic.nodemanager.server.ServerManager.start(ServerManager.java:331) NMProcess: at weblogic.nodemanager.server.Handler.handleStart(Handler.java:541) NMProcess: at weblogic.nodemanager.server.Handler.handleCommand(Handler.java:116) NMProcess: at weblogic.nodemanager.server.Handler.run(Handler.java:70) NMProcess: at java.lang.Thread.run(Thread.java:619) Error Starting server soa_server1: weblogic.nodemanager.NMException: Exception while starting server 'soa_server1' In the log file I've got this: Enter username to boot WebLogic server:Enter password to boot WebLogic server: There are 1 nested errors: weblogic.management.ManagementException: Booting as admin server, but servername, soa_server1, does not match the admin server name, AdminServer at weblogic.management.provider.internal.RuntimeAccessService.start(RuntimeAccessService.java:67) at weblogic.t3.srvr.ServerServicesManager.startService(ServerServicesManager.java:461) at weblogic.t3.srvr.ServerServicesManager.startInStandbyState(ServerServicesManager.java:166) at weblogic.t3.srvr.T3Srvr.initializeStandby(T3Srvr.java:749) at weblogic.t3.srvr.T3Srvr.startup(T3Srvr.java:488) at weblogic.t3.srvr.T3Srvr.run(T3Srvr.java:446) at weblogic.Server.main(Server.java:67) > <Mar 15, 2010 3:33:30 PM ART> <Notice> <WebLogicServer> <BEA-000365> <Server state changed to FAILED> <Mar 15, 2010 3:33:30 PM ART> <Error> <WebLogicServer> <BEA-000383> <A critical service failed. The server will shut itself down> <Mar 15, 2010 3:33:30 PM ART> <Notice> <WebLogicServer> <BEA-000365> <Server state changed to FORCE_SHUTTING_DOWN> <Mar 15, 2010 3:33:30 PM> <FINEST> <NodeManager> <Waiting for the process to die: 31144> <Mar 15, 2010 3:33:30 PM> <INFO> <NodeManager> <Server failed during startup so will not be restarted> <Mar 15, 2010 3:33:30 PM> <FINEST> <NodeManager> <runMonitor returned, setting finished=true and notifying waiters> Do you have any clue of what is happening? If you need more info, just ask for it. thanks in advance

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• Yet another (13)Permission denied error on Apache2 server

  - by lollercoaster

  I just can't figure it out. I'm running apache2 on a Ubuntu 10.04 i386 server. Whenever I visit my server (has an IP address, and is connected to internet with static IP xxx.xxx.xxx.xxx) so that's not the problem) in browser, mysub.domain.edu (renamed here), I get the following: Forbidden You don't have permission to access /index.html on this server The apache2 error log confirms this: [Mon Apr 18 02:38:20 2011] [error] [client zzz.zzz.zzz.zzz] (13)Permission denied: access to / denied I'll try to provide all necessary information below: 1) Contents of /etc/apache2/httpd.conf DirectoryIndex index.html index.php 2) Contents of /etc/apache2/sites-available/default <VirtualHost *:80> ServerAdmin [email protected] DocumentRoot /home/myusername/htdocs <Directory /> Options FollowSymLinks AllowOverride None </Directory> <Directory "/home/myusername/htdocs/"> Options Indexes FollowSymLinks MultiViews AllowOverride None order allow,deny allow from all DirectoryIndex index.html index.php Satisfy any </Directory> ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/ <Directory "/usr/lib/cgi-bin"> AllowOverride None Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch Order allow,deny Allow from all </Directory> ErrorLog /var/log/apache2/error.log # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. LogLevel warn CustomLog /var/log/apache2/access.log combined Alias /doc/ "/usr/share/doc/" <Directory "/usr/share/doc/"> Options Indexes MultiViews FollowSymLinks AllowOverride None Order deny,allow Deny from all Allow from 127.0.0.0/255.0.0.0 ::1/128 </Directory> ServerName mysub.domain.edu </VirtualHost> 3) Contents of /etc/apache2/sites-enabled/000-default <VirtualHost *:80> ServerAdmin [email protected] DocumentRoot /home/myusername/htdocs <Directory /> Options FollowSymLinks AllowOverride None </Directory> <Directory "/home/myusername/htdocs/"> Options Indexes FollowSymLinks MultiViews AllowOverride None order allow,deny allow from all DirectoryIndex index.html index.php Satisfy any </Directory> ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/ <Directory "/usr/lib/cgi-bin"> AllowOverride None Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch Order allow,deny Allow from all </Directory> ErrorLog /var/log/apache2/error.log # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. LogLevel warn CustomLog /var/log/apache2/access.log combined Alias /doc/ "/usr/share/doc/" <Directory "/usr/share/doc/"> Options Indexes MultiViews FollowSymLinks AllowOverride None Order deny,allow Deny from all Allow from 127.0.0.0/255.0.0.0 ::1/128 </Directory> ServerName mysub.domain.edu </VirtualHost> 4) Result of ls -l (when I'm using sudo -i to be root): root@myserver:/home/myusername# ls -l total 4 drwxr-xr-x 2 www-data root 4096 2011-04-18 03:04 htdocs 5) ps auxwww | grep -i apache root@myserver:/home# ps auxwww | grep -i apache root 15121 0.0 0.4 5408 2544 ? Ss 16:55 0:00 /usr/sbin/apache2 -k start www-data 15122 0.0 0.3 5180 1760 ? S 16:55 0:00 /usr/sbin/apache2 -k start www-data 15123 0.0 0.5 227020 2788 ? Sl 16:55 0:00 /usr/sbin/apache2 -k start www-data 15124 0.0 0.5 227020 2864 ? Sl 16:55 0:00 /usr/sbin/apache2 -k start root 29133 0.0 0.1 3320 680 pts/0 R+ 16:58 0:00 grep --color=auto -i apache 6) ls -al /home/myusername/htdocs/ root@myserver:/# ls -al /home/myusername/htdocs/ total 20 drwxr-xr-x 2 www-data root 4096 2011-04-18 03:04 . drw-r--r-- 4 myusername myusername 4096 2011-04-18 02:13 .. -rw-r--r-- 1 root root 69 2011-04-18 02:14 index.html I'm not currently using any .htaccess files in my web root (htdocs) folder in my user folder. I don't know what is wrong, I've been trying to fix his for over 12 hours and I've gotten nowhere. If you have any suggestions, I'm all ears...

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• Standard Oracle Fusion Middleware Installation fails on SOA ManagedServer start due to classpath pro

  - by Neuquino

  Hi, Trying to install Oracle Fusion Middleware 11gR2 on windows (same thing happens on Linux). I have followed the guidelines provided in the http://download.oracle.com/docs/cd/E12839_01/install.1111/e14318/toc.htm Installing the weblogic (11g) Oracle 11g databse installation Running the RCU utility to create schema Installed and copied relevant files for Java Bridge Configure the Fusion Middleware But i found that the SOA server is not getting up in the enterprise manager its showing as down. When i checked the logs iam getting the following error: oracle.jrf.wls.JRFStartup java.lang.ClassNotFoundException: oracle.jrf.wls.JRFStartup at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:247) at weblogic.management.deploy.classdeployment.ClassDeploymentManager.invokeClass(ClassDeploymentManager.java:253) at weblogic.management.deploy.classdeployment.ClassDeploymentManager.access$000(ClassDeploymentManager.java:54) at weblogic.management.deploy.classdeployment.ClassDeploymentManager$1.run(ClassDeploymentManager.java:205) Truncated. see log file for complete stacktrace <Jul 7, 2009 4:18:48 PM CEST> <Critical> <WebLogicServer> <BEA-000286> <Failed to invoke startup class "SOAStartupClass", java.lang.ClassNotFoundException: oracle.bpel.services.common.util.GenerateBPMCryptoKey java.lang.ClassNotFoundException: oracle.bpel.services.common.util.GenerateBPMCryptoKey at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:247) at weblogic.management.deploy.classdeployment.ClassDeploymentManager.invokeClass(ClassDeploymentManager.java:253) at weblogic.management.deploy.classdeployment.ClassDeploymentManager.access$000(ClassDeploymentManager.java:54) at weblogic.management.deploy.classdeployment.ClassDeploymentManager$1.run(ClassDeploymentManager.java:205) Truncated. see log file for complete stacktrace <Jul 7, 2009 4:19:27 PM CEST> <Error> <Deployer> <BEA-149205> <Failed to initialize the application 'SocketAdapter' due to error weblogic.application.ModuleException: The ra.xml <connectionfactory-impl-class> class 'oracle.tip.adapter.socket.SocketConnectionFactory' could not be loaded from the resource adapter archive/application because of the following error: java.lang.NoClassDefFoundError: oracle/tip/adapter/api/OracleConnectionFactory.weblogic.application.ModuleException: The ra.xml <connectionfactory-impl-class> class 'oracle.tip.adapter.socket.SocketConnectionFactory' could not be loaded from the resource adapter archive/application because of the following error: java.lang.NoClassDefFoundError: oracle/tip/adapter/api/OracleConnectionFactory at weblogic.connector.deploy.ConnectorModule.prepare(ConnectorModule.java:228) at weblogic.application.internal.flow.ModuleListenerInvoker.prepare(ModuleListenerInvoker.java:93) at weblogic.application.internal.flow.DeploymentCallbackFlow$1.next(DeploymentCallbackFlow.java:387) at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:37) at weblogic.application.internal.flow.DeploymentCallbackFlow.prepare(DeploymentCallbackFlow.java:58) Truncated. see log file for complete stacktrace <Jul 7, 2009 4:19:27 PM CEST> <Error> <Deployer> <BEA-149205> <Failed to initialize the application 'MQSeriesAdapter' due to error weblogic.application.ModuleException: The ra.xml <connectionfactory-impl-class> class 'oracle.tip.adapter.mq.ConnectionFactoryImpl' could not be loaded from the resource adapter archive/application because of the following error: java.lang.NoClassDefFoundError: oracle/tip/adapter/api/OracleConnectionFactory.weblogic.application.ModuleException: The ra.xml <connectionfactory-impl-class> class 'oracle.tip.adapter.mq.ConnectionFactoryImpl' could not be loaded from the resource adapter archive/application because of the following error: java.lang.NoClassDefFoundError: oracle/tip/adapter/api/OracleConnectionFactory at weblogic.connector.deploy.ConnectorModule.prepare(ConnectorModule.java:228) at weblogic.application.internal.flow.ModuleListenerInvoker.prepare(ModuleListenerInvoker.java:93) at weblogic.application.internal.flow.DeploymentCallbackFlow$1.next(DeploymentCallbackFlow.java:387) at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:37) at weblogic.application.internal.flow.DeploymentCallbackFlow.prepare(DeploymentCallbackFlow.java:58) Truncated. see log file for complete stacktrace <Jul 7, 2009 4:19:27 PM CEST> <Error> <Deployer> <BEA-149205> <Failed to initialize the application 'OracleAppsAdapter' due to error weblogic.application.ModuleException: java.lang.NoClassDefFoundError: oracle/tip/adapter/api/exception/PCResourceException.weblogic.application.ModuleException: java.lang.NoClassDefFoundError: oracle/tip/adapter/api/exception/PCResourceException at weblogic.connector.deploy.ConnectorModule.prepare(ConnectorModule.java:238) at weblogic.application.internal.flow.ModuleListenerInvoker.prepare(ModuleListenerInvoker.java:93) at weblogic.application.internal.flow.DeploymentCallbackFlow$1.next(DeploymentCallbackFlow.java:387) at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:37) at weblogic.application.internal.flow.DeploymentCallbackFlow.prepare(DeploymentCallbackFlow.java:58) Truncated. see log file for complete stacktrace java.lang.NoClassDefFoundError: oracle/tip/adapter/api/exception/PCResourceException at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Class.java:2427) at java.lang.Class.privateGetPublicMethods(Class.java:2547) at java.lang.Class.getMethods(Class.java:1410) at weblogic.connector.external.impl.RAComplianceChecker.checkOverrides(RAComplianceChecker.java:972) Truncated. see log file for complete stacktrace Can any one please tell me if i have missed any steps? thanks and regards, Naveen

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• Standard Oracle Fusion Middleware Installation fails on SOA ManagedServer start

  - by Neuquino

  Hi, Trying to install Oracle Fusion Middleware 11gR2 on windows (same thing happens on Linux). I have followed the guidelines provided in the http://download.oracle.com/docs/cd/E12839_01/install.1111/e14318/toc.htm Installing the weblogic (11g) Oracle 11g databse installation Running the RCU utility to create schema Installed and copied relevant files for Java Bridge Configure the Fusion Middleware But i found that the SOA server is not getting up in the enterprise manager its showing as down. When i checked the logs iam getting the following error: oracle.jrf.wls.JRFStartup java.lang.ClassNotFoundException: oracle.jrf.wls.JRFStartup at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:247) at weblogic.management.deploy.classdeployment.ClassDeploymentManager.invokeClass(ClassDeploymentManager.java:253) at weblogic.management.deploy.classdeployment.ClassDeploymentManager.access$000(ClassDeploymentManager.java:54) at weblogic.management.deploy.classdeployment.ClassDeploymentManager$1.run(ClassDeploymentManager.java:205) Truncated. see log file for complete stacktrace <Jul 7, 2009 4:18:48 PM CEST> <Critical> <WebLogicServer> <BEA-000286> <Failed to invoke startup class "SOAStartupClass", java.lang.ClassNotFoundException: oracle.bpel.services.common.util.GenerateBPMCryptoKey java.lang.ClassNotFoundException: oracle.bpel.services.common.util.GenerateBPMCryptoKey at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:247) at weblogic.management.deploy.classdeployment.ClassDeploymentManager.invokeClass(ClassDeploymentManager.java:253) at weblogic.management.deploy.classdeployment.ClassDeploymentManager.access$000(ClassDeploymentManager.java:54) at weblogic.management.deploy.classdeployment.ClassDeploymentManager$1.run(ClassDeploymentManager.java:205) Truncated. see log file for complete stacktrace <Jul 7, 2009 4:19:27 PM CEST> <Error> <Deployer> <BEA-149205> <Failed to initialize the application 'SocketAdapter' due to error weblogic.application.ModuleException: The ra.xml <connectionfactory-impl-class> class 'oracle.tip.adapter.socket.SocketConnectionFactory' could not be loaded from the resource adapter archive/application because of the following error: java.lang.NoClassDefFoundError: oracle/tip/adapter/api/OracleConnectionFactory.weblogic.application.ModuleException: The ra.xml <connectionfactory-impl-class> class 'oracle.tip.adapter.socket.SocketConnectionFactory' could not be loaded from the resource adapter archive/application because of the following error: java.lang.NoClassDefFoundError: oracle/tip/adapter/api/OracleConnectionFactory at weblogic.connector.deploy.ConnectorModule.prepare(ConnectorModule.java:228) at weblogic.application.internal.flow.ModuleListenerInvoker.prepare(ModuleListenerInvoker.java:93) at weblogic.application.internal.flow.DeploymentCallbackFlow$1.next(DeploymentCallbackFlow.java:387) at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:37) at weblogic.application.internal.flow.DeploymentCallbackFlow.prepare(DeploymentCallbackFlow.java:58) Truncated. see log file for complete stacktrace <Jul 7, 2009 4:19:27 PM CEST> <Error> <Deployer> <BEA-149205> <Failed to initialize the application 'MQSeriesAdapter' due to error weblogic.application.ModuleException: The ra.xml <connectionfactory-impl-class> class 'oracle.tip.adapter.mq.ConnectionFactoryImpl' could not be loaded from the resource adapter archive/application because of the following error: java.lang.NoClassDefFoundError: oracle/tip/adapter/api/OracleConnectionFactory.weblogic.application.ModuleException: The ra.xml <connectionfactory-impl-class> class 'oracle.tip.adapter.mq.ConnectionFactoryImpl' could not be loaded from the resource adapter archive/application because of the following error: java.lang.NoClassDefFoundError: oracle/tip/adapter/api/OracleConnectionFactory at weblogic.connector.deploy.ConnectorModule.prepare(ConnectorModule.java:228) at weblogic.application.internal.flow.ModuleListenerInvoker.prepare(ModuleListenerInvoker.java:93) at weblogic.application.internal.flow.DeploymentCallbackFlow$1.next(DeploymentCallbackFlow.java:387) at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:37) at weblogic.application.internal.flow.DeploymentCallbackFlow.prepare(DeploymentCallbackFlow.java:58) Truncated. see log file for complete stacktrace <Jul 7, 2009 4:19:27 PM CEST> <Error> <Deployer> <BEA-149205> <Failed to initialize the application 'OracleAppsAdapter' due to error weblogic.application.ModuleException: java.lang.NoClassDefFoundError: oracle/tip/adapter/api/exception/PCResourceException.weblogic.application.ModuleException: java.lang.NoClassDefFoundError: oracle/tip/adapter/api/exception/PCResourceException at weblogic.connector.deploy.ConnectorModule.prepare(ConnectorModule.java:238) at weblogic.application.internal.flow.ModuleListenerInvoker.prepare(ModuleListenerInvoker.java:93) at weblogic.application.internal.flow.DeploymentCallbackFlow$1.next(DeploymentCallbackFlow.java:387) at weblogic.application.utils.StateMachineDriver.nextState(StateMachineDriver.java:37) at weblogic.application.internal.flow.DeploymentCallbackFlow.prepare(DeploymentCallbackFlow.java:58) Truncated. see log file for complete stacktrace java.lang.NoClassDefFoundError: oracle/tip/adapter/api/exception/PCResourceException at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Class.java:2427) at java.lang.Class.privateGetPublicMethods(Class.java:2547) at java.lang.Class.getMethods(Class.java:1410) at weblogic.connector.external.impl.RAComplianceChecker.checkOverrides(RAComplianceChecker.java:972) Truncated. see log file for complete stacktrace Can any one please tell me if i have missed any steps? thanks and regards, Naveen

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• IIS 7.5 Manager crashes when adding a custom error page

  - by dig412

  I'm running a local IIS 7.5 server in Win 7 Pro, and I'm trying to add a custom error page for 403 responses. When I click OK to add a custom error page for my site, IIS Manager just vanishes. The server is still running, and I can re-start IIS Manager, but the new page has not been saved. I've also tried adding it directly to web.config, but that just gives me The page cannot be displayed because an internal server error has occurred. Does anyone know why this might be happening? Edit: The event log implies that an invalid character in the path caused the crash, but It occured even when I copied & pasted a path from a valid entry. Application error log: IISMANAGER_CRASH IIS Manager terminated unexpectedly. Exception:System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. --- System.ArgumentException: Illegal characters in path. at System.IO.Path.CheckInvalidPathChars(String path) at System.IO.Path.IsPathRooted(String path) at Microsoft.Web.Management.Iis.CustomErrors.CustomErrorsForm.OnAccept() at Microsoft.Web.Management.Client.Win32.TaskForm.OnOKButtonClick(Object sender, EventArgs e) at System.Windows.Forms.Control.OnClick(EventArgs e) at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent) at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ButtonBase.WndProc(Message& m) at System.Windows.Forms.Button.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context) at System.Windows.Forms.Form.ShowDialog(IWin32Window owner) at Microsoft.Web.Management.Host.UserInterface.ManagementUIService.ShowDialogInternal(Form form, IWin32Window parent) at Microsoft.Web.Management.Host.UserInterface.ManagementUIService.Microsoft.Web.Management.Client.Win32.IManagementUIService.ShowDialog(DialogForm form) at Microsoft.Web.Management.Client.Win32.ModulePage.ShowDialog(DialogForm form) at Microsoft.Web.Management.Iis.CustomErrors.CustomErrorsPage.AddCustomError() --- End of inner exception stack trace --- at System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at Microsoft.Web.Management.Client.TaskList.InvokeMethod(String methodName, Object userData) at Microsoft.Web.Management.Host.UserInterface.Tasks.MethodTaskItemLine.InvokeMethod() at System.Windows.Forms.LinkLabel.OnMouseUp(MouseEventArgs e) at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.Label.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context) at Microsoft.Web.Management.Host.Shell.ShellApplication.Execute(Boolean localDevelopmentMode, Boolean resetPreferences, Boolean resetPreferencesNoLaunch) Process:InetMgr

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• DRBD not syncing between my nodes when IP is reset

  - by ramdaz

  I am trying to setup DRBD by following the article at http://www.howtoforge.com/setting-up-network-raid1-with-drbd-on-ubuntu-11.10-p2 I am using Ubuntu 10.04 DRBD - 8.3.11 In the first run I had everything working perfectly and when shifting the systems to a production environment I decided to restart the Meta Data creation part and start from scratch. The IPs had changed entirely in the production environment. Issuing drdbadm create-md r0 in both the servers runs successfully. But when I do "drbdadm -- --overwrite-data-of-peer primary all" on the primary it fails to start the re sync. My config file is as given below resource r0 { protocol C; syncer { rate 50M; } startup { wfc-timeout 15; degr-wfc-timeout 60; } net { cram-hmac-alg sha1; shared-secret "aklsadkjlhdbskjndsf8738734jkfkjfkjf"; } on primaryds { device /dev/drbd0; disk /dev/md2; address 172.16.7.1:7788; meta-disk internal; } on secondaryds { device /dev/drbd0; disk /dev/md2; address 172.16.7.3:7788; meta-disk internal; } } Status on primary root at primaryds:~# cat /proc/drbd version: 8.3.7 (api:88/proto:86-91) GIT-hash: ea9e28dbff98e331a62bcbcc63a6135808fe2917 build by root at primaryds, 2012-05-12 15:08:01 0: cs:WFBitMapS ro:Primary/Secondary ds:UpToDate/Inconsistent C r---- ns:0 nr:0 dw:0 dr:200 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:5690352828 Status on secondary root at secondaryds:/etc/drbd.d# cat /proc/drbd version: 8.3.7 (api:88/proto:86-91) GIT-hash: ea9e28dbff98e331a62bcbcc63a6135808fe2917 build by root at secondaryds, 2012-05-12 15:25:25 0: cs:WFBitMapT ro:Secondary/Primary ds:Inconsistent/UpToDate C r---- ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:5690352828 Log of Primary May 30 13:42:23 primaryds kernel: [ 1584.057076] block drbd0: role( Secondary -> Primary ) disk( Inconsistent -> UpToDate ) May 30 13:42:23 primaryds kernel: [ 1584.086264] block drbd0: Forced to consider local data as UpToDate! May 30 13:42:23 primaryds kernel: [ 1584.086303] block drbd0: Creating new current UUID May 30 13:42:26 primaryds kernel: [ 1586.405551] block drbd0: drbd_sync_handshake: May 30 13:42:26 primaryds kernel: [ 1586.405564] block drbd0: self E8A075F378173D4B:0000000000000004:0000000000000000:0000000000000000 bits:1422588207 flags:0 May 30 13:42:26 primaryds kernel: [ 1586.405574] block drbd0: peer 0000000000000004:0000000000000000:0000000000000000:0000000000000000 bits:1422588207 flags:0 May 30 13:42:26 primaryds kernel: [ 1586.405582] block drbd0: uuid_compare()=2 by rule 30 May 30 13:42:26 primaryds kernel: [ 1586.405587] block drbd0: Becoming sync source due to disk states. May 30 13:42:26 primaryds kernel: [ 1586.405592] block drbd0: Writing the whole bitmap, full sync required after drbd_sync_handshake. May 30 13:42:27 primaryds kernel: [ 1588.171638] block drbd0: 5427 GB (1422588207 bits) marked out-of-sync by on disk bit-map. May 30 13:42:27 primaryds kernel: [ 1588.172769] block drbd0: conn( Connected -> WFBitMapS ) Log in Secondary May 30 13:42:24 secondaryds kernel: [ 1563.304894] block drbd0: peer( Secondary - Primary ) pdsk( Inconsistent - UpToDate ) May 30 13:42:24 secondaryds kernel: [ 1563.339674] block drbd0: drbd_sync_handshake: May 30 13:42:24 secondaryds kernel: [ 1563.339685] block drbd0: self 0000000000000004:0000000000000000:0000000000000000:0000000000000000 bits:1422588207 flags:0 May 30 13:42:24 secondaryds kernel: [ 1563.339695] block drbd0: peer E8A075F378173D4B:0000000000000004:0000000000000000:0000000000000000 bits:1422588207 flags:0 May 30 13:42:24 secondaryds kernel: [ 1563.339703] block drbd0: uuid_compare()=-2 by rule 20 May 30 13:42:24 secondaryds kernel: [ 1563.339709] block drbd0: Becoming sync target due to disk states. May 30 13:42:24 secondaryds kernel: [ 1563.339714] block drbd0: Writing the whole bitmap, full sync required after drbd_sync_handshake. May 30 13:42:26 secondaryds kernel: [ 1565.652342] block drbd0: 5427 GB (1422588207 bits) marked out-of-sync by on disk bit-map. May 30 13:42:26 secondaryds kernel: [ 1565.652965] block drbd0: conn( Connected - WFBitMapT ) The serves are not responding once it reaches this stage. Tried redoing it couple of time but noting happens. Why could the resync not be taking place? I would like some advice? Directions?

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• Attempting Unauthorized operation - SQL 2008 R2 install

  - by Fred L

  I've been banging against this for a few days. Keep getting this unauthorized error when trying to install SQL 2008 R2 on a Windows 7 machine. I've changed permissions on the key, does not fix... Created an admin user, gave specific permissions on that key, does not fix... Disabled all firewalls, installed from a local admin, does not fix... I'm out of patience and ideas! :) Help? 2012-07-06 13:09:11 Slp: Sco: Attempting to set value AppName 2012-07-06 13:09:11 Slp: SetValue: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VSTAHostConfig\SSIS_ScriptComponent\2.0, Name = AppName 2012-07-06 13:09:11 Slp: Sco: Attempting to create base registry key HKEY_LOCAL_MACHINE, machine 2012-07-06 13:09:11 SSIS: Processing Registry ACLs for SID 'S-1-5-21-2383144575-3599344511-819193542-1074' 2012-07-06 13:09:11 Slp: Sco: Attempting to open registry subkey SOFTWARE\Microsoft\Microsoft SQL Server\100 2012-07-06 13:09:11 SSIS: Setting permision on registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\100. 2012-07-06 13:09:11 Slp: Sco: Attempting to replace account with sid in security descriptor D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:11 Slp: ReplaceAccountWithSidInSddl -- SDDL to be processed: D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:11 Slp: ReplaceAccountWithSidInSddl -- SDDL to be returned: D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:11 Slp: Sco: Attempting to set security descriptor D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:11 Slp: Sco: Attempting to normalize security descriptor D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:11 Slp: Sco: Attempting to replace account with sid in security descriptor D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:11 Slp: ReplaceAccountWithSidInSddl -- SDDL to be processed: D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:11 Slp: ReplaceAccountWithSidInSddl -- SDDL to be returned: D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:11 Slp: Sco: Attempting to normalize security descriptor D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:11 Slp: Sco: Attempting to replace account with sid in security descriptor D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:11 Slp: ReplaceAccountWithSidInSddl -- SDDL to be processed: D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:11 Slp: ReplaceAccountWithSidInSddl -- SDDL to be returned: D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:11 Slp: Prompting user if they want to retry this action due to the following failure: 2012-07-06 13:09:11 Slp: ---------------------------------------- 2012-07-06 13:09:11 Slp: The following is an exception stack listing the exceptions in outermost to innermost order 2012-07-06 13:09:11 Slp: Inner exceptions are being indented 2012-07-06 13:09:11 Slp: 2012-07-06 13:09:11 Slp: Exception type: Microsoft.SqlServer.Configuration.Sco.ScoException 2012-07-06 13:09:11 Slp: Message: 2012-07-06 13:09:11 Slp: Attempted to perform an unauthorized operation. 2012-07-06 13:09:11 Slp: Data: 2012-07-06 13:09:11 Slp: WatsonData = 100 2012-07-06 13:09:11 Slp: DisableRetry = true 2012-07-06 13:09:11 Slp: Inner exception type: System.UnauthorizedAccessException 2012-07-06 13:09:11 Slp: Message: 2012-07-06 13:09:11 Slp: Attempted to perform an unauthorized operation. 2012-07-06 13:09:11 Slp: Stack: 2012-07-06 13:09:11 Slp: at System.Security.AccessControl.Win32.GetSecurityInfo(ResourceType resourceType, String name, SafeHandle handle, AccessControlSections accessControlSections, RawSecurityDescriptor& resultSd) 2012-07-06 13:09:11 Slp: at System.Security.AccessControl.NativeObjectSecurity.CreateInternal(ResourceType resourceType, Boolean isContainer, String name, SafeHandle handle, AccessControlSections includeSections, Boolean createByName, ExceptionFromErrorCode exceptionFromErrorCode, Object exceptionContext) 2012-07-06 13:09:11 Slp: at Microsoft.SqlServer.Configuration.Sco.SqlRegistrySecurity..ctor(ResourceType resourceType, SafeRegistryHandle handle, AccessControlSections includeSections) 2012-07-06 13:09:11 Slp: at Microsoft.SqlServer.Configuration.Sco.SqlRegistrySecurity.Create(InternalRegistryKey key) 2012-07-06 13:09:11 Slp: at Microsoft.SqlServer.Configuration.Sco.InternalRegistryKey.GetAccessControl() 2012-07-06 13:09:11 Slp: at Microsoft.SqlServer.Configuration.Sco.InternalRegistryKey.SetSecurityDescriptor(String sddl, Boolean overwrite) 2012-07-06 13:09:11 Slp: ---------------------------------------- 2012-07-06 13:09:24 Slp: User has chosen to retry this action 2012-07-06 13:09:24 Slp: Sco: Attempting to normalize security descriptor D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:24 Slp: Sco: Attempting to replace account with sid in security descriptor D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:24 Slp: ReplaceAccountWithSidInSddl -- SDDL to be processed: D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:24 Slp: ReplaceAccountWithSidInSddl -- SDDL to be returned: D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:24 Slp: Sco: Attempting to normalize security descriptor D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:24 Slp: Sco: Attempting to replace account with sid in security descriptor D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:24 Slp: ReplaceAccountWithSidInSddl -- SDDL to be processed: D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:24 Slp: ReplaceAccountWithSidInSddl -- SDDL to be returned: D:(A;OICI;KR;;;S-1-5-21-2383144575-3599344511-819193542-1074) 2012-07-06 13:09:24 Slp: Prompting user if they want to retry this action due to the following failure: 2012-07-06 13:09:24 Slp: ----------------------------------------

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• How to obtain a random sub-datatable from another data table

  - by developerit

  Introduction In this article, I’ll show how to get a random subset of data from a DataTable. This is useful when you already have queries that are filtered correctly but returns all the rows. Analysis I came across this situation when I wanted to display a random tag cloud. I already had the query to get the keywords ordered by number of clicks and I wanted to created a tag cloud. Tags that are the most popular should have more chance to get picked and should be displayed larger than less popular ones. Implementation In this code snippet, there is everything you need. ' Min size, in pixel for the tag Private Const MIN_FONT_SIZE As Integer = 9 ' Max size, in pixel for the tag Private Const MAX_FONT_SIZE As Integer = 14 ' Basic function that retreives Tags from a DataBase Public Shared Function GetTags() As MediasTagsDataTable ' Simple call to the TableAdapter, to get the Tags ordered by number of clicks Dim dt As MediasTagsDataTable = taMediasTags.GetDataValide ' If the query returned no result, return an empty DataTable If dt Is Nothing OrElse dt.Rows.Count < 1 Then Return New MediasTagsDataTable End If ' Set the font-size of the group of data ' We are dividing our results into sub set, according to their number of clicks ' Example: 10 results -> [0,2] will get font size 9, [3,5] will get font size 10, [6,8] wil get 11, ... ' This is the number of elements in one group Dim groupLenth As Integer = CType(Math.Floor(dt.Rows.Count / (MAX_FONT_SIZE - MIN_FONT_SIZE)), Integer) ' Counter of elements in the same group Dim counter As Integer = 0 ' Counter of groups Dim groupCounter As Integer = 0 ' Loop througt the list For Each row As MediasTagsRow In dt ' Set the font-size in a custom column row.c_FontSize = MIN_FONT_SIZE + groupCounter ' Increment the counter counter += 1 ' If the group counter is less than the counter If groupLenth <= counter Then ' Start a new group counter = 0 groupCounter += 1 End If Next ' Return the new DataTable with font-size Return dt End Function ' Function that generate the random sub set Public Shared Function GetRandomSampleTags(ByVal KeyCount As Integer) As MediasTagsDataTable ' Get the data Dim dt As MediasTagsDataTable = GetTags() ' Create a new DataTable that will contains the random set Dim rep As MediasTagsDataTable = New MediasTagsDataTable ' Count the number of row in the new DataTable Dim count As Integer = 0 ' Random number generator Dim rand As New Random() While count < KeyCount Randomize() ' Pick a random row Dim r As Integer = rand.Next(0, dt.Rows.Count - 1) Dim tmpRow As MediasTagsRow = dt(r) ' Import it into the new DataTable rep.ImportRow(tmpRow) ' Remove it from the old one, to be sure not to pick it again dt.Rows.RemoveAt(r) ' Increment the counter count += 1 End While ' Return the new sub set Return rep End Function Pro’s This method is good because it doesn’t require much work to get it work fast. It is a good concept when you are working with small tables, let says less than 100 records. Con’s If you have more than 100 records, out of memory exception may occur since we are coping and duplicating rows. I would consider using a stored procedure instead.

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• Michael Crump&rsquo;s notes for 70-563 PRO &ndash; Designing and Developing Windows Applications usi

  - by mbcrump

  TIME TO GO PRO! This is my notes for 70-563 PRO – Designing and Developing Windows Applications using .NET Framework 3.5 I created it using several resources (various certification web sites, msdn, official ms 70-548 book). The reason that I created this review is because a) I am taking the exam. b) MS did not create a book for this exam. Use the(MS 70-548)book. c) To make sure I am familiar with each before the exam. I hope that it provides a good start for your own notes. I hope that someone finds this useful. At least, it will give you a starting point of what to expect to know on the PRO exam. Also, for those wondering, the PRO exam does contains very little code. It is basically all theory. 1. Validation Controls – How to prevent users from entering invalid data on forms. (MaskedTextBox control and RegEx) 2. ServiceController – used to start and control the behavior of existing services. 3. User Feedback (know winforms Status Bar, Tool Tips, Color, Error Provider, Context-Sensitive and Accessibility) 4. Specific (derived) exceptions must be handled before general (base class) exceptions. By moving the exception handling for the base type Exception to after exception handling of ArgumentNullException, all ArgumentNullException thrown by the Helper method will be caught and logged correctly. 5. A heartbeat method is a method exposed by a Web service that allows external applications to check on the status of the service. 6. New users must master key tasks quickly. Giving these tasks context and appropriate detail will help. However, advanced users will demand quicker paths. Shortcuts, accelerators, or toolbar buttons will speed things along for the advanced user. 7. MSBuild uses project files to instruct the build engine what to build and how to build it. MSBuild project files are XML files that adhere to the MSBuild XML schema. The MSBuild project files contain complete file, build action, and dependency information for each individual projects. 8. Evaluating whether or not to fix a bug involves a triage process. You must identify the bug's impact, set the priority, categorize it, and assign a developer. Many times the person doing the triage work will assign the bug to a developer for further investigation. In fact, the workflow for the bug work item inside of Team System supports this step. Developers are often asked to assess the impact of a given bug. This assessment helps the person doing the triage make a decision on how to proceed. When assessing the impact of a bug, you should consider time and resources to fix it, bug risk, and impacts of the bug. 9. In large projects it is generally impossible and unfeasible to fix all bugs because of the impact on schedule and budget. 10. Code reviews should be conducted by a technical lead or a technical peer. 11. Testing Applications 12. WCF Services – application state 13. SQL Server 2005 / 2008 Express Edition – reliable storage of data / Microsoft SQL Server 3.5 Compact Database– used for client computers to retrieve and save data from a shared location. 14. SQL Server 2008 Compact Edition – used for minimum possible memory and can synchronize data with a corporate SQL Server 2008 Database. Supports offline user and minimum dependency on external components. 15. MDI and SDI Forms (specifically IsMDIContainer) 16. GUID – in the case of data warehousing, it is important to define unique keys. 17. Encrypting / Security Data 18. Understanding of Isolated Storage/Proper location to store items 19. LINQ to SQL 20. Multithreaded access 21. ADO.NET Entity Framework model 22. Marshal.ReleaseComObject 23. Common User Interface Layout (ComboBox, ListBox, Listview, MaskedTextBox, TextBox, RichTextBox, SplitContainer, TableLayoutPanel, TabControl) 24. DataSets Class - http://msdn.microsoft.com/en-us/library/system.data.dataset%28VS.71%29.aspx 25. SQL Server 2008 Reporting Services (SSRS) 26. SystemIcons.Shield (Vista UAC) 27. Leverging stored procedures to perform data manipulation for a database schema that can change. 28. DataContext 29. Microsoft Windows Installer Packages, ClickOnce(bootstrapping features), XCopy. 30. Client Application Services – will authenticate users by using the same data source as a ASP.NET web application. 31. SQL Server 2008 Caching 32. StringBuilder 33. Accessibility Guidelines for Windows Applications http://msdn.microsoft.com/en-us/library/ms228004.aspx 34. Logging erros 35. Testing performance related issues. 36. Role Based Security, GenericIdentity and GenericPrincipal 37. System.Net.CookieContainer will store session data for webapps (see isolated storage for winforms) 38. .NET CLR Profiler tool will identify objects that cause performance issues. 39. ADO.NET Synchronization (SyncGroup) 40. Globalization - CultureInfo 41. IDisposable Interface- reports on several questions relating to this. 42. Adding timestamps to determine whether data has changed or not. 43. Converting applications to .NET Framework 3.5 44. MicrosoftReportViewer 45. Composite Controls 46. Windows Vista KNOWN folders. 47. Microsoft Sync Framework 48. TypeConverter -Provides a unified way of converting types of values to other types, as well as for accessing standard values and sub properties. http://msdn.microsoft.com/en-us/library/system.componentmodel.typeconverter.aspx 49. Concurrency control mechanisms The main categories of concurrency control mechanisms are: Optimistic - Delay the checking of whether a transaction meets the isolation rules (e.g., serializability and recoverability) until its end, without blocking any of its (read, write) operations, and then abort a transaction, if the desired rules are violated. Pessimistic - Block operations of a transaction, if they may cause violation of the rules. Semi-optimistic - Block operations in some situations, and do not block in other situations, while delaying rules checking to transaction's end, as done with optimistic. 50. AutoResetEvent 51. Microsoft Messaging Queue (MSMQ) 4.0 52. Bulk imports 53. KeyDown event of controls 54. WPF UI components 55. UI process layer 56. GAC (installing, removing and queuing) 57. Use a local database cache to reduce the network bandwidth used by applications. 58. Sound can easily be annoying and distracting to users, so use it judiciously. Always give users the option to turn sound off. Because a user might have sound off, never convey important information through sound alone.

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• Constructor parameter validation in C# - Best practices

  - by MPelletier

  What is the best practice for constructor parameter validation? Suppose a simple bit of C#: public class MyClass { public MyClass(string text) { if (String.IsNullOrEmpty(text)) throw new ArgumentException("Text cannot be empty"); // continue with normal construction } } Would it be acceptable to throw an exception? The alternative I encountered was pre-validation, before instantiating: public class CallingClass { public MyClass MakeMyClass(string text) { if (String.IsNullOrEmpty(text)) { MessageBox.Show("Text cannot be empty"); return null; } else { return new MyClass(text); } } }

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• ¿Es más barato desarrollar a medida que adquirir un ERP?

  - by Luis Alberto Quilez

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} La clave está en el tiempo. Cuando abordamos un desarrollo a medida, estamos pensando únicamente en las necesidades de hoy. Tenemos un proyecto concreto, un determinado alcance funcional y conocemos las herramientas que hoy tenemos disponibles. Somos los que mejor conocemos nuestra empresa de hoy, sus procesos y el desarrollo parece una buena opción, pues las licencias de las herramientas de desarrollo son económicas y el coste de la tarifa diaria de programación es asequible, y entonces, caemos en la trampa del corto plazo y vamos adelante. Es muy posible que este desarrollo salga bien, que estemos orgullosos de nuestro trabajo, e incluso que proclamemos a los 4 vientos el dinero que nos hemos ahorrado. Sin embargo el mundo no se para, el negocio no se para, la adaptación debe ser permanente, nuestros clientes, internos y externos, tendrán nuevas exigencias y nuestro desarrollo no estará terminado, tendremos que integrarlo con otras áreas, tendremos que tratar de darle mayor funcionalidad y alcance, tendremos que adaptarlo a las nuevas tecnologías, permitir que la información se analice, se comparta, se acceda desde nuevos dispositivos … y veremos en primera persona cómo la trampa del desarrollo se cierra sobre nuestras cabezas, nunca estará terminado, la tecnología que usamos un día se quedará obsoleta, el ritmo de exigencia por funcionalidad e integración será cada vez mayor y no podremos sino poner más y más recursos dedicados al mantenimiento de un desarrollo propio, que no deja de comer, que me obliga a gastar más y más cada día y del que no puedo salir. Al poco tiempo me he convertido en una empresa de desarrollo de software dentro de mi propia empresa y ni tengo los recursos económicos para hacerlo viable, ni tengo las capacidades humanas y de inversión para responder a lo que se me exige desde el negocio. Así que pensemos, desde el principio, en que nuestra empresa debe perdurar muchos años, y hagamos el análisis de costes bajo esta perspectiva a la hora de tomar la decisión y veremos entonces que la adquisición de un ERP es mucho más económica que el desarrollo a medida. Por otro lado tenemos la integración. Un sistema de producción, requiere la asignación de recursos, que a su vez requieren de un plan de desarrollo, una formación o un cálculo de su nómina; también requiere de una cuenta contable, de una gestión de compras o de una asignación de costes y claro,de todos estos puntos nos vamos dando cuenta sobre la marcha, cuando en un sistema de gestión integral (ERP) lo tenemos disponible desde el primer momento. Claro que no nos vale un ERP cerrado, poco flexible y que no me permita diferenciar a mi empresa. Tenemos que buscar un socio tecnológico que nos acompañe, que asuma la inversión en tecnología y que me vaya suministrando versiones y soluciones acordes a las exigencias de los tiempos, de hoy y de mañana, pero además que me permita adaptar los flujos e innovar en los procesos para que podamos diferenciar nuestra empresa de la competencia, hoy y mañana. Veremos cómo, con la decisión de un ERP, flexible y abierto, los números salen y en el largo plazo es mucho más económica la decisión de adquirir un ERP que de optar por el desarrollo. Luis Alberto Quilez v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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• weblogic.socket.MaxMessageSizeExceededException: Incoming message of size: '10000080' bytes exceeds

  - by Ramkumar Menon

  If you are using BPEL Client APIs against WLS 9.2, and if you run into this exception, pass the following JVM argument to get things going, -Dweblogic.MaxMessageSize=value Make the value high enough for all that data to come through and you should be good.

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• An Honest look at SharePoint Web Services

  - by juanlarios

  INTRODUCTION If you are a SharePoint developer you know that there are two basic ways to develop against SharePoint. 1) The object Model 2) Web services. SharePoint object model has the advantage of being quite rich. Anything you can do through the SharePoint UI as an administrator or end user, you can do through the object model. In fact everything that is done through the UI is done through the object model behind the scenes. The major disadvantage to getting at SharePoint this way is that the code needs to run on the server. This means that all web parts, event receivers, features, etc… all of this is code that is deployed to the server. The second way to get to SharePoint is through the built in web services. There are many articles on how to manipulate web services, how to authenticate to them and interact with them. The basic idea is that a remote application or process can contact SharePoint through a web service. Lots has been written about how great these web services are. This article is written to document the limitations, some of the issues and frustrations with working with SharePoint built in web services. Ultimately, for the tasks I was given to , SharePoint built in web services did not suffice. My evaluation of SharePoint built in services was compared against creating my own WCF Services to do what I needed. The current project I'm working on right now involved several "integration points". A remote application, installed on a separate server was to contact SharePoint and perform an task or operation. So I decided to start up Visual Studio and built a DLL and basically have 2 layers of logic. An integration layer and a data layer. A good friend of mine pointed me to SOLID principles and referred me to some videos and tutorials about it. I decided to implement the methodology (although a lot of the principles are common sense and I already incorporated in my coding practices). I was to deliver this dll to the application team and they would simply call the methods exposed by this dll and voila! it would do some task or operation in SharePoint. SOLUTION My integration layer implemented an interface that defined some of the basic integration tasks that I was to put together. My data layer was about the same, it implemented an interface with some of the tasks that I was going to develop. This gave me the opportunity to develop different data layers, ultimately different ways to get at SharePoint if I needed to. This is a classic SOLID principle. In this case it proved to be quite helpful because I wrote one data layer completely implementing SharePoint built in Web Services and another implementing my own WCF Service that I wrote. I should mention there is another layer underneath the data layer. In referencing SharePoint or WCF services in my visual studio project I created a class for every web service call. So for example, if I used List.asx. I created a class called "DocumentRetreival" this class would do the grunt work to connect to the correct URL, It would perform the basic operation of contacting the service and so on. If I used a view.asmx, I implemented a class called "ViewRetrieval" with the same idea as the last class but it would now interact with all he operations in view.asmx. This gave my data layer the ability to perform multiple calls without really worrying about some of the grunt work each class performs. This again, is a classic SOLID principle. So, in order to compare them side by side we can look at both data layers and with is involved in each. Lets take a look at the "Create Project" task or operation. The integration point is described as , "dll is to provide a way to create a project in SharePoint". Projects , in this case are basically document libraries. I am to implement a way in which a remote application can create a document library in SharePoint. Easy enough right? Use the list.asmx Web service in SharePoint. So here we go! Lets take a look at the code. I added the List.asmx web service reference to my project and this is the class that contacts it:  class DocumentRetrieval     {         private ListsSoapClient _service;      d   private bool _impersonation;         public DocumentRetrieval(bool impersonation, string endpt)         {             _service = new ListsSoapClient();             this.SetEndPoint(string.Format("{0}/{1}", endpt, ConfigurationManager.AppSettings["List"]));             _impersonation = impersonation;             if (_impersonation)             {                 _service.ClientCredentials.Windows.ClientCredential.Password = ConfigurationManager.AppSettings["password"];                 _service.ClientCredentials.Windows.ClientCredential.UserName = ConfigurationManager.AppSettings["username"];                 _service.ClientCredentials.Windows.AllowedImpersonationLevel =                     System.Security.Principal.TokenImpersonationLevel.Impersonation;             }     private void SetEndPoint(string p)          {             _service.Endpoint.Address = new EndpointAddress(p);          }          /// <summary>         /// Creates a document library with specific name and templateID         /// </summary>         /// <param name="listName">New list name</param>         /// <param name="templateID">Template ID</param>         /// <returns></returns>         public XmlElement CreateLibrary(string listName, int templateID, ref ExceptionContract exContract)         {             XmlDocument sample = new XmlDocument();             XmlElement viewCol = sample.CreateElement("Empty");             try             {                 _service.Open();                 viewCol = _service.AddList(listName, "", templateID);             }             catch (Exception ex)             {                 exContract = new ExceptionContract("DocumentRetrieval/CreateLibrary", ex.GetType(), "Connection Error", ex.StackTrace, ExceptionContract.ExceptionCode.error);                             }finally             {                 _service.Close();             }                                      return viewCol;         } } There was a lot more in this class (that I am not including) because i was reusing the grunt work and making other operations with LIst.asmx, For example, updating content types, changing or configuring lists or document libraries. One of the first things I noticed about working with the built in services is that you are really at the mercy of what is available to you. Before creating a document library (Project) I wanted to expose a IsProjectExisting method. This way the integration or data layer could recognize if a library already exists. Well there is no service call or method available to do that check. So this is what I wrote:   public bool DocLibExists(string listName, ref ExceptionContract exContract)         {             try             {                 var allLists = _service.GetListCollection();                                return allLists.ChildNodes.OfType<XmlElement>().ToList().Exists(x => x.Attributes["Title"].Value ==listName);             }             catch (Exception ex)             {                 exContract = new ExceptionContract("DocumentRetrieval/GetList/GetListWSCall", ex.GetType(), "Unable to Retrieve List Collection", ex.StackTrace, ExceptionContract.ExceptionCode.error);             }             return false;         } This really just gets an XMLElement with all the lists. It was then up to me to sift through the clutter and noise and see if Document library already existed. This took a little bit of getting used to. Now instead of working with code, you are working with XMLElement response format from web service. I wrote a LINQ query to go through and find if the attribute "Title" existed and had a value of the listname then it would return True, if not False. I didn't particularly like working this way. Dealing with XMLElement responses and then having to manipulate it to get at the exact data I was looking for. Once the check for the DocLibExists, was done, I would either create the document library or send back an error indicating the document library already existed. Now lets examine the code that actually creates the document library. It does what you are really after, it creates a document library. Notice how the template ID is really an integer. Every document library template in SharePoint has an ID associated with it. Document libraries, Image Library, Custom List, Project Tasks, etc… they all he a unique integer associated with it. Well, that's great but the client came back to me and gave me some specifics that each "project" or document library, should have. They specified they had 3 types of projects. Each project would have unique views, about 10 views for each project. Each Project specified unique configurations (auditing, versioning, content types, etc…) So what turned out to be a simple implementation of creating a document library as a repository for a project, turned out to be quite involved.  The first thing I thought of was to create a template for document library. There are other ways you can do this too. Using the web Service call, you could configure views, versioning, even content types, etc… the only catch is, you have to be working quite extensively with CAML. I am not fond of CAML. I can do it and work with it, I just don't like doing it. It is quite touchy and at times it is quite tough to understand where errors were made with CAML statements. Working with Web Services and CAML proved to be quite annoying. The service call would return a generic error message that did not particularly point me to a CAML statement syntax error, or even a CAML error. I was not sure if it was a security , performance or code based issue. It was quite tough to work with. At times it was difficult to work with because of the way SharePoint handles metadata. There are "Names", "Display Name", and "StaticName" fields. It was quite tough to understand at times, which one to use. So it took a lot of trial and error. There are tools that can help with CAML generation. There is also now intellisense for CAML statements in Visual Studio that might help but ultimately I'm not fond of CAML with Web Services.   So I decided on the template. So my plan was to create create a document library, configure it accordingly and then use The Template Builder that comes with the SharePoint SDK. This tool allows you to create site templates, list template etc… It is quite interesting because it does not generate an STP file, it actually generates an xml definition and a feature you can activate and make that template available on a site or site collection. The first issue I experienced with this is that one of the specifications to this template was that the "All Documents" view was to have 2 web parts on it. Well, it turns out that using the template builder , it did not include the web parts as part of the list template definition it generated. It backed up the settings, the views, the content types but not the custom web parts. I still decided to try this even without the web parts on the page. This new template defined a new Document library definition with a unique ID. The problem was that the service call accepts an int but it only has access to the built in library int definitions. Any new ones added or created will not be available to create. So this made it impossible for me to approach the problem this way.     I should also mention that one of the nice features about SharePoint is the ability to create list templates, back them up and then create lists based on that template. It can all be done by end user administrators. These templates are quite unique because they are saved as an STP file and not an xml definition. I also went this route and tried to see if there was another service call where I could create a document library based no given template name. Nope! none.      After some thinking I decide to implement a WCF service to do this creation for me. I was quite certain that the object model would allow me to create document libraries base on a template in which an ID was required and also templates saved as STP files. Now I don't want to bother with posting the code to contact WCF service because it's self explanatory, but I will post the code that I used to create a list with custom template. public ServiceResult CreateProject(string name, string templateName, string projectId)         {             string siteurl = SPContext.Current.Site.Url;             Guid webguid = SPContext.Current.Web.ID;                        using (SPSite site = new SPSite(siteurl))             {                 using (SPWeb rootweb = site.RootWeb)                 {                     SPListTemplateCollection temps = site.GetCustomListTemplates(rootweb);                     ProcessWeb(siteurl, webguid, web => Act_CreateProject(web, name, templateName, projectId, temps));                 }//SpWeb             }//SPSite              return _globalResult;                   }         private void Act_CreateProject(SPWeb targetsite, string name, string templateName, string projectId, SPListTemplateCollection temps) {                         var temp = temps.Cast<SPListTemplate>().FirstOrDefault(x => x.Name.Equals(templateName));             if (temp != null)             {                             try                 {                                         Guid listGuid = targetsite.Lists.Add(name, "", temp);                     SPList newList = targetsite.Lists[listGuid];                     _globalResult = new ServiceResult(true, "Success", "Success");                 }                 catch (Exception ex)                 {                     _globalResult = new ServiceResult(false, (string.IsNullOrEmpty(ex.Message) ? "None" : ex.Message + " " + templateName), ex.StackTrace.ToString());                 }                                       }        private void ProcessWeb(string siteurl, Guid webguid, Action<SPWeb> action) {                        using (SPSite sitecollection = new SPSite(siteurl)) {                 using (SPWeb web = sitecollection.AllWebs[webguid]) {                     action(web);                 }                     }                  } This code is actually some of the code I implemented for the service. there was a lot more I did on Project Creation which I will cover in my next blog post. I implemented an ACTION method to process the web. This allowed me to properly dispose the SPWEb and SPSite objects and not rewrite this code over and over again. So I implemented a WCF service to create projects for me, this allowed me to do a lot more than just create a document library with a template, it now gave me the flexibility to do just about anything the client wanted at project creation. Once this was implemented , the client came back to me and said, "we reference all our projects with ID's in our application. we want SharePoint to do the same". This has been something I have been doing for a little while now but I do hope that SharePoint 2010 can have more of an answer to this and address it properly. I have been adding metadata to SPWebs through property bag. I believe I have blogged about it before. This time it required metadata added to a document library. No problem!!! I also mentioned these web parts that were to go on the "All Documents" View. I took the opportunity to configure them to the appropriate settings. There were two settings that needed to be set on these web parts. One of them was a Project ID configured in the webpart properties. The following code enhances and replaces the "Act_CreateProject " method above:  private void Act_CreateProject(SPWeb targetsite, string name, string templateName, string projectId, SPListTemplateCollection temps) {                         var temp = temps.Cast<SPListTemplate>().FirstOrDefault(x => x.Name.Equals(templateName));             if (temp != null)             {                 SPLimitedWebPartManager wpmgr = null;                               try                 {                                         Guid listGuid = targetsite.Lists.Add(name, "", temp);                     SPList newList = targetsite.Lists[listGuid];                     SPFolder rootFolder = newList.RootFolder;                     rootFolder.Properties.Add(KEY, projectId);                     rootFolder.Update();                     if (rootFolder.ParentWeb != targetsite)                         rootFolder.ParentWeb.Dispose();                     if (!templateName.Contains("Natural"))                     {                         SPView alldocumentsview = newList.Views.Cast<SPView>().FirstOrDefault(x => x.Title.Equals(ALLDOCUMENTS));                         SPFile alldocfile = targetsite.GetFile(alldocumentsview.ServerRelativeUrl);                         wpmgr = alldocfile.GetLimitedWebPartManager(PersonalizationScope.Shared);                         ConfigureWebPart(wpmgr, projectId, CUSTOMWPNAME);                                              alldocfile.Update();                     }                                        if (newList.ParentWeb != targetsite)                         newList.ParentWeb.Dispose();                     _globalResult = new ServiceResult(true, "Success", "Success");                 }                 catch (Exception ex)                 {                     _globalResult = new ServiceResult(false, (string.IsNullOrEmpty(ex.Message) ? "None" : ex.Message + " " + templateName), ex.StackTrace.ToString());                 }                 finally                 {                     if (wpmgr != null)                     {                         wpmgr.Web.Dispose();                         wpmgr.Dispose();                     }                 }             }                         }       private void ConfigureWebPart(SPLimitedWebPartManager mgr, string prjId, string webpartname)         {             var wp = mgr.WebParts.Cast<System.Web.UI.WebControls.WebParts.WebPart>().FirstOrDefault(x => x.DisplayTitle.Equals(webpartname));             if (wp != null)             {                           (wp as ListRelationshipWebPart.ListRelationshipWebPart).ProjectID = prjId;                 mgr.SaveChanges(wp);             }         }   This Shows you how I was able to set metadata on the document library. It has to be added to the RootFolder of the document library, Unfortunately, the SPList does not have a Property bag that I can add a key\value pair to. It has to be done on the root folder. Now everything in the integration will reference projects by ID's and will not care about names. My, "DocLibExists" will now need to be changed because a web service is not set up to look at property bags.  I had to write another method on the Service to do the equivalent but with ID's instead of names.  The second thing you will notice about the code is the use of the Webpartmanager. I have seen several examples online, and also read a lot about memory leaks, The above code does not produce memory leaks. The web part manager creates an SPWeb, so just dispose it like I did. CONCLUSION This is a long long post so I will stop here for now, I will continue with more comparisons and limitations in my next post. My conclusion for this example is that Web Services will do the trick if you can suffer through CAML and if you are doing some simple operations. For Everything else, there's WCF! **** fireI apologize for the disorganization of this post, I was on a bus on a 12 hour trip to IOWA while I wrote it, I was half asleep and half awake, hopefully it makes enough sense to someone.

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• AS11 Oracle B2B Sync Support - Series 1

  - by sinkarbabu.kirubanithi

  Synchronous message support has been enabled in Oracle B2B 11G. This would help customers to send the business message and receive the corresponding business response synchronously. We would like to keep this blog entry as three part series, first one would carry Oracle B2B configuration related details followed by 'how it can be consumed and utilized in an enterprise' using composites backed model. And, the last one would talk about more sophisticated seeded support built on Oracle B2B platform (Note: the last one is still in description phase and ETA hasn't been finalized yet). Details: In an effort to enable synchronous processing in Oracle B2B, we provided a platform using the existing 'callout' mechanism. In this case, we expect the 'callout' attached to the agreement to deliver incoming business message (inbound) to back-end application and get the corresponding business response from back-end and deliver it to Oracle B2B as its output. The output of 'callout' would be processed as outbound message and the same will be attached as a response for the inbound message. Requirements to enable Sync Support: Outbound side: Outbound Agreement - to send business message request Inbound Agreement - to receive business message response Inbound side: Inbound Agreement - to receive business message request Outbound Agreement - to send business message response Agreement Level Callout - to deliver the inbound request to back-end and get the corresponding business response This feature is supported only for HTTP based transport to exchange messages with Trading Partners. One may initiate the outbound message (enqueue) using any of the available Transports in Oracle B2B. Configuration: Outbound side: Please add "syncresponse=true" as "Additional Transport Header" parameter for remote Trading Partner's HTTP delivery channel configuration. This would enable Oracle B2B to process the HTTP response as inbound message and deliver the same to back-end application. All other configuration related to Agreement and Document setup remain same. Inbound side: There is no change in Agreement and Document setup. To enable "Sync Support", you need to build a 'callout' that takes the responsibility of delivering inbound message to back-end and get the corresponding business response from the back-end and attach the same as its output. Oracle B2B treats the output of 'callout' as outbound message and deliver it to Trading Partner as synchronous HTTP response. The requests that needs to processed synchronously should be received by "syncreceiver" (http://:/b2b/syncreceiver) endpoint in Oracle B2B. Exception Handling: Existing Oracle B2B exception handling applies to this use case as well. Here's the sample callout, SampleSyncCallout.java We will get you second part that talks about 'SOA composites' backed model to design the "Sync Support" use case from back-end to Trading Partners, stay tuned.

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• C#/.NET Little Pitfalls: The Dangers of Casting Boxed Values

  - by James Michael Hare

  Starting a new series to parallel the Little Wonders series.  In this series, I will examine some of the small pitfalls that can occasionally trip up developers. Introduction: Of Casts and Conversions What happens when we try to assign from an int and a double and vice-versa? 1: double pi = 3.14; 2: int theAnswer = 42; 3:  4: // implicit widening conversion, compiles! 5: double doubleAnswer = theAnswer; 6:  7: // implicit narrowing conversion, compiler error! 8: int intPi = pi; As you can see from the comments above, a conversion from a value type where there is no potential data loss is can be done with an implicit conversion.  However, when converting from one value type to another may result in a loss of data, you must make the conversion explicit so the compiler knows you accept this risk.  That is why the conversion from double to int will not compile with an implicit conversion, we can make the conversion explicit by adding a cast: 1: // explicit narrowing conversion using a cast, compiler 2: // succeeds, but results may have data loss: 3: int intPi = (int)pi; So for value types, the conversions (implicit and explicit) both convert the original value to a new value of the given type.  With widening and narrowing references, however, this is not the case.  Converting reference types is a bit different from converting value types.  First of all when you perform a widening or narrowing you don’t really convert the instance of the object, you just convert the reference itself to the wider or narrower reference type, but both the original and new reference type both refer back to the same object. Secondly, widening and narrowing for reference types refers the going down and up the class hierarchy instead of referring to precision as in value types.  That is, a narrowing conversion for a reference type means you are going down the class hierarchy (for example from Shape to Square) whereas a widening conversion means you are going up the class hierarchy (from Square to Shape).  1: var square = new Square(); 2:  3: // implicitly convers because all squares are shapes 4: // (that is, all subclasses can be referenced by a superclass reference) 5: Shape myShape = square; 6:  7: // implicit conversion not possible, not all shapes are squares! 8: // (that is, not all superclasses can be referenced by a subclass reference) 9: Square mySquare = (Square) myShape; So we had to cast the Shape back to Square because at that point the compiler has no way of knowing until runtime whether the Shape in question is truly a Square.  But, because the compiler knows that it’s possible for a Shape to be a Square, it will compile.  However, if the object referenced by myShape is not truly a Square at runtime, you will get an invalid cast exception. Of course, there are other forms of conversions as well such as user-specified conversions and helper class conversions which are beyond the scope of this post.  The main thing we want to focus on is this seemingly innocuous casting method of widening and narrowing conversions that we come to depend on every day and, in some cases, can bite us if we don’t fully understand what is going on!  The Pitfall: Conversions on Boxed Value Types Can Fail What if you saw the following code and – knowing nothing else – you were asked if it was legal or not, what would you think: 1: // assuming x is defined above this and this 2: // assignment is syntactically legal. 3: x = 3.14; 4:  5: // convert 3.14 to int. 6: int truncated = (int)x; You may think that since x is obviously a double (can’t be a float) because 3.14 is a double literal, but this is inaccurate.  Our x could also be dynamic and this would work as well, or there could be user-defined conversions in play.  But there is another, even simpler option that can often bite us: what if x is object? 1: object x; 2:  3: x = 3.14; 4:  5: int truncated = (int) x; On the surface, this seems fine.  We have a double and we place it into an object which can be done implicitly through boxing (no cast) because all types inherit from object.  Then we cast it to int.  This theoretically should be possible because we know we can explicitly convert a double to an int through a conversion process which involves truncation. But here’s the pitfall: when casting an object to another type, we are casting a reference type, not a value type!  This means that it will attempt to see at runtime if the value boxed and referred to by x is of type int or derived from type int.  Since it obviously isn’t (it’s a double after all) we get an invalid cast exception! Now, you may say this looks awfully contrived, but in truth we can run into this a lot if we’re not careful.  Consider using an IDataReader to read from a database, and then attempting to select a result row of a particular column type: 1: using (var connection = new SqlConnection("some connection string")) 2: using (var command = new SqlCommand("select * from employee", connection)) 3: using (var reader = command.ExecuteReader()) 4: { 5: while (reader.Read()) 6: { 7: // if the salary is not an int32 in the SQL database, this is an error! 8: // doesn't matter if short, long, double, float, reader [] returns object! 9: total += (int) reader["annual_salary"]; 10: } 11: } Notice that since the reader indexer returns object, if we attempt to convert using a cast to a type, we have to make darn sure we use the true, actual type or this will fail!  If the SQL database column is a double, float, short, etc this will fail at runtime with an invalid cast exception because it attempts to convert the object reference! So, how do you get around this?  There are two ways, you could first cast the object to its actual type (double), and then do a narrowing cast to on the value to int.  Or you could use a helper class like Convert which analyzes the actual run-time type and will perform a conversion as long as the type implements IConvertible. 1: object x; 2:  3: x = 3.14; 4:  5: // if you want to cast, must cast out of object to double, then 6: // cast convert. 7: int truncated = (int)(double) x; 8:  9: // or you can call a helper class like Convert which examines runtime 10: // type of the value being converted 11: int anotherTruncated = Convert.ToInt32(x); Summary You should always be careful when performing a conversion cast from values boxed in object that you are actually casting to the true type (or a sub-type). Since casting from object is a widening of the reference, be careful that you either know the exact, explicit type you expect to be held in the object, or instead avoid the cast and use a helper class to perform a safe conversion to the type you desire. Technorati Tags: C#,.NET,Pitfalls,Little Pitfalls,BlackRabbitCoder

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• Silverlight Cream for November 20, 2011 - 2 -- #1170

  - by Dave Campbell

  In this Issue: Michael Washington, Oliver Fuh, Jeremy Likness, Derik Whittaker, Jesse Liberty, Jeff Blankenburg(-2-), and Michael Crump. Above the Fold: Silverlight: "Handling Extremely Large Data Sets in Silverlight" Jeremy Likness WP7: "31 Days of Mango | Day #8: Contacts API" Jeff Blankenburg LightSwitch: "LightSwitch Chat Application Using A Data Source Extension" Michael Washington Shoutouts: Michael Palermo's latest Desert Mountain Developers is up Michael Washington's latest Visual Studio #LightSwitch Daily is up Check out Shawn Wildermuth's take on the AppStore and WP7 in general: 40,000 Apps - What Does It Mean? Be sure to check out Jesse Liberty & Paul Betts new book: Programming Reactive Extensions and LINQ, I've just had a little time to look at mine, but don't let the size fool you... this is the good stuff! From SilverlightCream.com: LightSwitch Chat Application Using A Data Source Extension In his latest LightSwitch post, Michael Washington gives up code that will enable two people using the same LightSwitch app to chat. Great detailed tutorial as usual! Handling AdControl Fetching Exception WindowsPhoneGeek turns the blog reigns over to Oliver Fuh for this post about using the AdControl in your WP7 app and handling a common exception you get with the Microsoft AdControl Handling Extremely Large Data Sets in Silverlight In this excerpt from his book, Jeremy Likness discusses reading *LARGE* data sets with Silverlight using 3 different patterns: OData, WCF RIA Services, and MVVM. Using MVVM with the AutoCompleteTextBox in Silverlight 4 Derik Whittaker takes a break from WinRT to discuss the Silverlight 4 AutoCompleteTextBox and MVVM ... including a custom Behavior to allow the backing property to be updated and a command to trigger background searches Yet Another Podcast #52–Peter Torr on Windows Phone Multitasking Jesse Liberty scored Peter Torr on his Latest Yet Another Podcast .. talking about Multitasking on Windows Phone including background agents, the backstack, and other Mango features 31 Days of Mango | Day #8: Contacts API Jeff Blankenburg's Day 8 is about a new namespace on WP7: Microsoft.Phone.UserData ... now giving us the ability to treat the user's contact list like a local database 31 Days of Mango | Day #9: Calendar API On Day 9 in his series, Jeff Blankenburg revisits the Microsoft.Phone.UserData namespace and looks at another set of data: the calendar Want to Decompile Silverlight XAP files? Try JustDecompile Beta! Michael Crump has a post up about the new free developer productivity tool from Telerik that provides assembly browsing and decompiling: JustDecompile ... Just download it! Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

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• SSIS Catalog, Windows updates and deployment failures due to System.Core mismatch

  - by jamiet

  This is a heads-up for anyone doing development on SSIS. On my current project where we are implementing a SQL Server Integration Services (SSIS) 2012 solution we recently encountered a situation where we were unable to deploy any of our projects even though we had successfully deployed in the past. Any attempt to use the deployment wizard resulted in this error dialog: The text of the error (for all you search engine crawlers out there) was: A .NET Framework error occurred during execution of user-defined routine or aggregate "create_key_information": System.IO.FileLoadException: Could not load file or assembly 'System.Core, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) ---> System.IO.FileLoadException: The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) System.IO.FileLoadException: System.IO.FileLoadException:     at Microsoft.SqlServer.IntegrationServices.Server.Security.CryptoGraphy.CreateSymmetricKey(String algorithm)    at Microsoft.SqlServer.IntegrationServices.Server.Security.CryptoGraphy.CreateKeyInformation(SqlString algorithmName, SqlBytes& key, SqlBytes& IV) . (Microsoft SQL Server, Error: 6522) After some investigation and a bit of back and forth with some very helpful members of the SSIS product team (hey Matt, Wee Hyong) it transpired that this was due to a .Net Framework fix that had been delivered via Windows Update. I took a look at the server update history and indeed there have been some recently applied .Net Framework updates: This fix had (in the words of Matt Masson) “somehow caused a mismatch on System.Core for SQLCLR” and, as you may know, SQLCLR is used heavily within the SSIS Catalog. The fix was pretty simple – restart SQL Server. This causes the assemblies to be upgraded automatically. If you are using Data Quality Services (DQS) you may have experienced similar problems which are documented at Upgrade SQLCLR Assemblies After .NET Framework Update. I am hoping the SSIS team will follow-up with a more thorough explanation on their blog soon. You DBAs out there may be questioning why Windows Update is set to automatically apply updates on our production servers. We’re checking that out with our hosting provider right now You have been warned! @Jamiet

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