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  • Is it safe to reuse javax.xml.ws.Service objects

    - by Noel Ang
    I have JAX-WS style web service client that was auto-generated with the NetBeans IDE. The generated proxy factory (extends javax.xml.ws.Service) delegates proxy creation to the various Service.getPort methods. The application that I am maintaining instantiates the factory and obtains a proxy each time it calls the targetted service. Creating the new proxy factory instances repeatedly has been shown to be expensive, given that the WSDL documentation supplied to the factory constructor, an HTTP URI, is re-retrieved for each instantiation. We had success in improving the performance by caching the WSDL. But this has ugly maintenance and packaging implications for us. I would like to explore the suitability of caching the proxy factory itself. Is it safe, e.g., can two different client classes, executing on the same JVM and targetting the same web service, safely use the same factory to obtain distinct proxy objects (or a shared, reentrant one)? I've been unable to find guidance from either the JAX-WS specification nor the javax.xml.ws API documentation. The factory-proxy multiplicity is unclear to me. Having Service.getPort rather than Service.createPort does not inspire confidence.

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  • Jar dependencies to use jetty httpclient

    - by Alfred
    Hi all, I want to use the jetty httpclient(in netbeans) but have the least number of jar dependencies. I know I can import all jars from the jetty lib folder to my project but I would like to know what the minimum number of dependencies are and how you did find this out? Our there tools to find jar dependencies?

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  • Why does XPath.selectNodes(context) always use the whole document in JDOM

    - by Simeon
    Hi, I'm trying to run the same query on several different contexts, but I always get the same result. This is an example xml: <root> <p> <r> <t>text</t> </r> </p> <t>text2</t> </root> So this is what I'm doing: final XPath xpath = XPath.newInstance("//t"); List<Element> result = xpath.selectNodes(thisIsThePelement); // and I've debuged it, it really is the <p> element And I always get both <t> elements in the result list. I need just the <t> inside the <p> I'm passing to the XPath object. Any ideas would be of great help, thanks.

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  • Get Cell RSSI(Network Signal Strength) on Android 1.5

    - by Brandon
    Is there any way to retrieve the current cellular Signal Strength (RSSI) on Android 1.5? I know there's a way to listen for signal strength updates through the TelephonyManager, but this seems to only give a "state," not a numeric value. Is using the RSSI field on a neighboring cell fairly accurate? I'm guessing not, but I'm running out of ideas.

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  • Losing sessions on GlassFish

    - by synti
    I have a web application that logs users in a @SessionScoped managed bean. It's all the basic stuff, pretty much like this: users logs in using regular http form and gets redirect to user area (wich is protected using a filter). But if any resource on that area is accessed, the request somehow uses a new session, wich has no managed bean, no user, and the filter does his job, redirecting him to login page. Here's the login form: <h:form> <h:outputLabel for="email" value="Email "/> <p:inputText id="email" size="30" value="#{loginManager.email}"/> <h:outputLabel for="password" value="Password "/> <p:password id="password" size="12" value="#{loginManager.password}"/> <p:commandButton value="Login" action="#{loginManager.login()}"/> </h:form> The loginManager managed bean: @ManagedBean @SessionScoped public class LoginManager implements Serializable { @EJB private UserService userService; private User user; private String email; private String password; public String login() { user = userService.findBy(email, password); if (user == null) { // FacesMessage stuff } else { return "/user/welcome.xhtml?faces-redirect=true"; } } public String logout() { FacesContext.getCurrentInstance().getExternalContext().invalidateSession(); return "/index.xhtml?faces-redirect=true"; } // Getters, setters (no setter for user) and serialVersionUID And then comes the filter that protects the user area: @WebFilter(urlPatterns="/user/*", displayName="UserFilter") public class UserFilter implements Filter { @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { HttpSession session = ((HttpServletRequest)request).getSession(false); LoginManager loginManager = (LoginManager) session.getAttribute("loginManager"); if (loginManager == null || !loginManager.hasUser()) { HttpServletResponse resp = (HttpServletResponse) response; resp.sendRedirect("index.xhtml"); } final User user = loginManager.getUser(); if (user.isValid()) { chain.doFilter(request, response); } else { HttpServletResponse resp = (HttpServletResponse) response; resp.sendRedirect("index.xhtml"); } } The UserService is just a stateless EJB that handles persistence. Part of the JSF for user area: <h:form> <p:panelMenu> <p:submenu label="Items"> <p:menuitem value="Add item" action="#{userItens.addItems}" ajax="false"/> <p:menuitem value="My items" /> </p:submenu> </p:panelMenu> </h:form> And finally the userItens managed bean. @ManagedBean @RequestScoped public class UserItens { private User user; @PostConstruct private void init() { HttpSession session = (HttpSession) FacesContext.getCurrentInstance() .getExternalContext().getSession(false); LoginManager loginManager = (LoginManager) session.getAttribute("loginManager"); if (loginManager != null) user = loginManager.getUser(); } public String addItems() { // Doesn't get here. Seems like UserFilter comes first, doesn't find // an user and redirects. } I'm using glassfish and session timeout is now on 0.

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  • in a J2EE application when does a listener get called?

    - by josh
    I have a J2EE app and it has a listener in web.xml. Listener contains a method called contextInitialized I want to know when does contextInitialized actually get called? From my reading I understand that it gets called when deploying the application. Can there be situations/scenario's where it could be called after the application has been deployed? Say that I am in a Clustered GlassFish app server environment. Could it be called after the application has been deployed?

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  • Why is the setContextClassLoader() method placed on Thread ?

    - by Roman
    Why is the setContextClassLoader() method placed on thread ? What different thread have different classloaders? The question is what if i extended a classloader , loaded there some new classes. to the my custom classloader. Now , I want it to be the context classloader , so I call the method (Thread.currentThread().setContextClassLoader(loader)). Are these new classes awailable only in the context of the current Thread ? ( or how does it work ?) Thanks

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  • WAS Server - Apache critical problem

    - by murali
    hi, I am facing critical problem for integration of WAS Server-Apache Server.I am using the WAS server for the connection pooling for the database calling...and my webpage is hosted in the apache server and the webpage serarch box is calling the WAS Server and i am using struts frame work for autocomplete action... but it is working in IE of all versions.. but it is not working any browser... the JS file HTTPsuggestions are going to the structs frame work... but the response is is giving as null even i am giving the xmlHttpGetSuggestions.status =200 || xmlHttpGetSuggestions.status =0 but i am not getting the autocomplete feature. can you please help to slove this problem..... Thanks, Murali

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  • Message Queue with 'Message Barrier' Feature?

    - by Lajos Nagy
    Is there a message queue implementation that allows breaking up work into 'batches' by inserting 'message barriers' into the message stream? Let me clarify. No messages after a message barrier should be delivered to any consumers of the queue, until all messages before the barrier are consumed. Sort of like a synchronization point. I'd also prefer if all consumers received notification when they reached a barrier. Anything like this out there?

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  • Launch .jar files with command line arguments (but with no console window)

    - by Virat Kadaru
    I have to do a demo of an application, the application has a server.jar and client.jar. Both have command line arguments and are executable. I need to launch two instances of server.jar and two instances of client.jar. I thought that using a batch file was the way to go, but, the batch file executes the first command (i.e. server.bat [argument1] [argument2]) and does not do anything else unless I close the first instance, in which case it then runs the 2nd command. And also the I do not want a blank console window to open (or be minimized) What I really need is a batch script that will just launch these apps without any console windows and launch all instances that I need. Thanks in Advance! EDIT: javaw: works if I type the command into the console window individually. If I put the same in the batch file, it will behave as before. Console window opens, one instance starts (whichever was first) and it does not proceed further unless I close the application in which case it runs the 2nd command. I want it to run all commands silently SOLUTION: Found the solution, below is the contents of my batch file @echo off start /B server.jar [arg1] [arg2] start /B server.jar [arg3] [arg4] @echo on this opens, runs all the commands and closes the window, does not wait for the command to finish.

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  • Cannot insert non latin symbols in MySQL

    - by glebreutov
    I'm writing web-app using MySQL version 5.1.45, Tomcat 5.5.28 and Hibernate 3 When I'm trying to save string that contains non-latin characters (for example ??????) error occurs: 1589 [main] WARN org.hibernate.util.JDBCExceptionReporter - SQL Error: 1366, SQLState: HY000 1589 [main] ERROR org.hibernate.util.JDBCExceptionReporter - Incorrect string value: '\xD0\xA3\xD0\xBF\xD1\x8F...' for column 'name' at row 1 Hibernate connection settings <property name="connection.driver_class">com.mysql.jdbc.Driver</property> <property name="connection.url">jdbc:mysql://localhost/E2012?characterEncoding=UTF8&amp;useUnicode=true</property> <property name="connection.username">***</property> <property name="connection.password">***</property> <property name="hibernate.connection.charSet">UTF8</property> MySQL config My.cnf [client] default-character-set=utf8 [mysqld] default-character-set=utf8 Even query set name utf-8 doesn't resolve problem Thanks for help!

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  • How can I interrupt a ServerSocket accept() method?

    - by lukeo05
    Hi, In my main thread I have a while(listening) loop which calls accept() on my ServerSocket object, then starts a new client thread and adds it to a Collection when a new client is accepted. I also have an Admin thread which I want to use to issue commands, like 'exit', which will cause all the client threads to be shut down, shut itself down, and shut down the main thread, by turning listening to false. However, the accept() call in the while(listening) loop blocks, and there doesn't seem to be any way to interrupt it, so the while condition cannot be checked again and the program cannot exit! Is there a better way to do this? Or some way to interrupt the blocking method? Thanks!

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  • How do I get spring-ws + tomcat to log errors

    - by Dave
    I'm creating a Spring-WS based webservice and running it in tomcat. I made some change and now get a fault with OperationUnsupportedException. I'd like to see the entire stack trace that Spring-WS is getting, but cannot figure out how to have it logged. Does anybody know how to have this stack trace logged somewhere?

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  • URL load error during adding

    - by Steven
    hi, i have a string say Path ="C:\AAA\bin" which is a path to a project's bin folder. I used new URL(Path) during invocation of addURL method of URLClassLoader class. ex- addURL(sysLoader,new URL(Path)) ; its giving unknown protocol:c exception whats the problem?Help

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  • Limit Connections with semaphores

    - by Robert
    I'm trying to limit the number of connections my server will accept using semaphores, but when running, my code doesn't seem to make this restriction - am I using the semaphore correctly? eg. I have hardcoded the number of permit as 2, but I can connect an unlimited number of clients... public class EServer implements Runnable { private ServerSocket serverSocket; private int numberofConnections = 0; private Semaphore sem = new Semaphore(2); private volatile boolean keepProcessing = true; public EServer(int port) throws IOException { serverSocket = new ServerSocket(port); } @Override public void run() { while (keepProcessing) { try { sem.acquire(); Socket socket = serverSocket.accept(); process(socket, getNextConnectionNumber()); } catch (Exception e) { } finally { sem.release(); } } closeIgnoringException(serverSocket); } private synchronized int getNextConnectionNumber() { return ++numberofConnections; } // processing related methods }

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  • onchange force page submit

    - by cometta
    <form jwcid="@Form" listener="listener:updateStaff"> <select jwcid="staffselect@Select" multiple="ognl:false" validators="validators:required" onchange="this.form.submit()" listener="listener:updateStaff"> <span jwcid="@For" source="ognl:hrStaff" value="ognl:currentHrStaff" index="ognl:currentHrStaffIndex"> <option class="text11" jwcid="@Option" selected="ognl:hrStaffSelection[currentHrStaffIndex]" label="ognl:currentHrStaff"/> </span> </select> </form> when onchange on selectbox, this form will be submitted and my pageValidate() will be called follow by upadteStaff() listener method. I wonder, when such submission is fired, can onchange='' pass a flag ('selectboxisfired' string) that i able to capture inside pagevalidate() 'selectboxisfired'? this will allow my logic inside pagevalidate to indicate is triggered by selectbox.

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  • how to show integer values in JComboBox?

    - by Edan
    Hello, I would like to know how to set a JComboBox that contain integers values that I could save. Here is the definitions of values: public class Item { private String itemDesc; private int itemType; public static int ENTREE=0; public static int MAIN_MEAL=1; public static int DESSERT=2; public static int DRINK=3; private float price; int[] itemTypeArray = { ENTREE, MAIN_MEAL, DESSERT, DRINK }; Object[][] data = {{itemDesc, new Integer(itemType), new Float(price)}}; . . . } Now, I want the add a JComboBox that the user will choose 1 of the items (ENTREE, MAIN_MEAL...) and then I could set the number as an Integer. I know that JComboBox need to be something like that: JComboBox combo = new JComboBox(itemTypeArray.values()); JOptionPane.showMessageDialog( null, combo,"Please Enter Item Type", `JOptionPane.QUESTION_MESSAGE);` What am I doing wrong?

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  • XML strings in JAXB

    - by OOO
    I have a JPA entity class mimicking a table. Something like this: @XmlType(name="MyClassElementType") public class MyClass { String name; String xmlDesc; public MyClass() {} @XmlElement String getName() { return name; } void setName(String name) { this.name = name; } @XmlElement String getXmlDesc() { return xmlDesc; } void setXmlDesc(String xmlDesc) { this.xmlDesc = xmlDesc; } } In a Jersey REST get call I'm trying to return this class: @Get @Produces("application/xml") public MyClass get() { return myClass; } Now I'm expecting the already xml string(xmlStr) to be returned as is, but Jersey/JAXB escapes it... So anyway around this?

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  • where should i put the configuration files in a webservice

    - by KItis
    Could some one help me on this problem. i have webservice , which reads data from configuration files. When i run this webservice from eclipse , i give absolute the path for these webservices of these configuration files , but when i shift the webservice in to server and run, it can not read the config file. so how can i solve this problem. is there a relative path that webservice can understand during run time.

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  • Reducing the pain writing integration and system tests

    - by mdma
    I would like to make integration tests and system tests for my applications but producing good integration and system tests have often needed so much effort that I have not bothered. The few times I tried, I wrote custom, application-specific test harnesses, which felt like re-inventing the wheel each time. I wonder if this is the wrong approach. Is there a "standard" approach to integration and full system testing? EDIT: To clarify, it's automated tests, for desktop and web applications. Ideally a complete test suite that exercises the full functionality of the application.

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  • JSF 2.0 Problem

    - by Sarang
    I am doing a project where I am using JSF 2.0 & Primefaces UI Components. There is a tab view component with tabs, "Day","Week" & "Month". In all tab, I have to display Bar Charts in each. For the same, I am fetching three list using the following three method. In the following code, UpdateCountHelper is fetching the data from database. So, UpdateCountHelper is taking some time for fetching data. This is code for fetching lists : public List<UpdateCount> getDayUpdateCounts() { if (projectFlag == true) { if (displayFlag == 1) { dayUpdateCounts = UpdateCountHelper.getProjectUpdates(1); } else { dayUpdateCounts = UpdateCountHelper.getProjectUpdates(name, 1); } } else { dayUpdateCounts = UpdateCountHelper.getResourceUpdates(userName, 1); } return dayUpdateCounts; } public List<UpdateCount> getMonthUpdateCounts() { if (projectFlag == true) { if (displayFlag == 1) { monthUpdateCounts = UpdateCountHelper.getProjectUpdates(30); } else { monthUpdateCounts = UpdateCountHelper.getProjectUpdates(name, 30); } } else { monthUpdateCounts = UpdateCountHelper.getResourceUpdates(userName, 30); } return monthUpdateCounts; } public List<UpdateCount> getWeekUpdateCounts() { if (projectFlag == true) { if (displayFlag == 1) { weekUpdateCounts = UpdateCountHelper.getProjectUpdates(7); } else { weekUpdateCounts = UpdateCountHelper.getProjectUpdates(name, 7); } } else { weekUpdateCounts = UpdateCountHelper.getResourceUpdates(userName, 7); } return weekUpdateCounts; } This is code for UI of Bar Chart : <p:panel id="Chart"> <p:tabView dynamic="false" cache="false"> <p:tab title="Day"> <p:panel id="chartDayPanel"> <center> <h:outputText id="projectWiseDayText" rendered="#{systemUtilizationServiceBean.projectFlag}" value="Project Wise Day Update"/> <p:columnChart id="projectWiseDayUpdateChart" rendered="#{systemUtilizationServiceBean.projectFlag}" value="#{systemUtilizationServiceBean.dayUpdateCounts}" var="dayWiseUpdate" xfield="#{dayWiseUpdate.name}" height="200px" width="640px"> <p:chartSeries label="Project Wise Current Day Update" value="#{dayWiseUpdate.noUpdates}"/> </p:columnChart> <h:outputText id="resourceWiseDayText" rendered="#{systemUtilizationServiceBean.resourceFlag}" value="Resource Wise Day Update"/> <p:columnChart id="resourceWiseDayUpdateChart" rendered="#{systemUtilizationServiceBean.resourceFlag}" value="#{systemUtilizationServiceBean.dayUpdateCounts}" var="dayWiseResourceUpdate" xfield="#{dayWiseResourceUpdate.name}" height="200px" width="640px"> <p:chartSeries label="Resource Wise Current Day Update" value="#{dayWiseResourceUpdate.noUpdates}"/> </p:columnChart> </center> </p:panel> </p:tab> <p:tab title="Week"> <p:panel id="chartWeekPanel"> <center> <h:outputText id="projectWiseWeekText" rendered="#{systemUtilizationServiceBean.projectFlag}" value="Project Wise Week Update"/> <p:columnChart id="projectWiseWeekUpdateChart" rendered="#{systemUtilizationServiceBean.projectFlag}" value="#{systemUtilizationServiceBean.weekUpdateCounts}" var="weekWiseUpdate" xfield="#{weekWiseUpdate.name}" height="200px" width="640px"> <p:chartSeries label="Project Wise Current Week Update" value="#{weekWiseUpdate.noUpdates}"/> </p:columnChart> <h:outputText id="resourceWiseWeekText" rendered="#{systemUtilizationServiceBean.resourceFlag}" value="Resource Wise Week Update"/> <p:columnChart id="resourceWiseWeekUpdateChart" rendered="#{systemUtilizationServiceBean.resourceFlag}" value="#{systemUtilizationServiceBean.weekUpdateCounts}" var="weekWiseResourceUpdate" xfield="#{weekWiseResourceUpdate.name}" height="200px" width="640px"> <p:chartSeries label="Resource Wise Current Week Update" value="#{weekWiseResourceUpdate.noUpdates}"/> </p:columnChart> </center> </p:panel> </p:tab> <p:tab title="Month"> <p:panel id="chartMonthPanel"> <center> <h:outputText id="projectWiseMonthText" rendered="#{systemUtilizationServiceBean.projectFlag}" value="Project Wise Month Update"/> <p:columnChart id="projectWiseMonthUpdateChart" rendered="#{systemUtilizationServiceBean.projectFlag}" value="#{systemUtilizationServiceBean.monthUpdateCounts}" var="monthWiseUpdate" xfield="#{monthWiseUpdate.name}" height="200px" width="640px"> <p:chartSeries label="Project Wise Current Month Update" value="#{monthWiseUpdate.noUpdates}"/> </p:columnChart> <h:outputText id="resourceWiseMonthText" rendered="#{systemUtilizationServiceBean.resourceFlag}" value="Resource Wise Month Update"/> <p:columnChart id="resourceWiseMonthUpdateChart" rendered="#{systemUtilizationServiceBean.resourceFlag}" value="#{systemUtilizationServiceBean.monthUpdateCounts}" var="monthWiseResourceUpdate" xfield="#{monthWiseResourceUpdate.name}" height="200px" width="640px"> <p:chartSeries label="Resource Wise Current Month Update" value="#{monthWiseResourceUpdate.noUpdates}"/> </p:columnChart> </center> </p:panel> </p:tab> </p:tabView> </p:panel> Now, I have to display same data in other tabview with same tabs as mentioned above & only thing is now I have to display in Pie Chart. Now in pie chart, I am using the same lists. So, it will again fetch the data from database & waste time. To solve that problem I have created other three lists & have given only reference of those previous lists. So, now no database fetching occur. The Code for applying the reference is : public List<UpdateCount> getPieDayUpdateCounts() { pieDayUpdateCounts = dayUpdateCounts; return pieDayUpdateCounts; } public List<UpdateCount> getPieMonthUpdateCounts() { pieMonthUpdateCounts = monthUpdateCounts; return pieMonthUpdateCounts; } public List<UpdateCount> getPieWeekUpdateCounts() { pieWeekUpdateCounts = weekUpdateCounts; return pieWeekUpdateCounts; } But, over here the problem occurring is that only chart of which the tab is enable is displayed but the other remaining 2 tabs are not showing any chart. The code for UI is : <p:tabView dynamic="false" cache="false"> <p:tab title="Day"> <center> <p:panel id="pieChartDayPanel"> <h:outputText id="projectWiseDayPieChartText" rendered="#{systemUtilizationServiceBean.projectFlag}" value="Project Wise Day Update"/> <p:pieChart id="projectWiseDayUpdatePieChart" rendered="#{systemUtilizationServiceBean.projectFlag}" value="#{systemUtilizationServiceBean.dayUpdateCounts}" var="dayWisePieUpdate" categoryField="#{dayWisePieUpdate.name}" dataField="#{dayWisePieUpdate.noUpdates}" height="200" width="200"/> <h:outputText id="resourceWiseDayPieChartText" rendered="#{systemUtilizationServiceBean.resourceFlag}" value="Resource Wise Day Update"/> <p:pieChart id="resourceWiseDayUpdatePieChart" rendered="#{systemUtilizationServiceBean.resourceFlag}" value="#{systemUtilizationServiceBean.dayUpdateCounts}" var="dayWiseResourcePieUpdate" categoryField="#{dayWiseResourcePieUpdate.name}" dataField="#{dayWiseResourcePieUpdate.noUpdates}" height="200" width="200"/> </p:panel> </center> </p:tab> <p:tab title="Week"> <center> <p:panel id="pieChartWeekPanel"> <h:outputText id="projectWiseWeekPieChartText" rendered="#{systemUtilizationServiceBean.projectFlag}" value="Project Wise Week Update"/> <p:pieChart id="projectWiseWeekUpdatePieChart" rendered="#{systemUtilizationServiceBean.projectFlag}" value="#{systemUtilizationServiceBean.weekUpdateCounts}" var="weekWisePieUpdate" categoryField="#{weekWisePieUpdate.name}" dataField="#{weekWisePieUpdate.noUpdates}" height="200" width="200"/> <h:outputText id="resourceWiseWeekPieChartText" rendered="#{systemUtilizationServiceBean.resourceFlag}" value="Resource Wise Week Update"/> <p:pieChart id="resourceWiseWeekUpdatePieChart" rendered="#{systemUtilizationServiceBean.resourceFlag}" value="#{systemUtilizationServiceBean.weekUpdateCounts}" var="weekWiseResourcePieUpdate" categoryField="#{weekWiseResourcePieUpdate.name}" dataField="#{weekWiseResourcePieUpdate.noUpdates}" height="200" width="200"/> </p:panel> </center> </p:tab> <p:tab title="Month"> <center> <p:panel id="pieChartMonthPanel"> <h:outputText id="projectWiseMonthPieChartText" rendered="#{systemUtilizationServiceBean.projectFlag}" value="Project Wise Month Update"/> <p:pieChart id="projectWiseMonthUpdatePieChart" rendered="#{systemUtilizationServiceBean.projectFlag}" value="#{systemUtilizationServiceBean.monthUpdateCounts}" var="monthWisePieUpdate" categoryField="#{monthWisePieUpdate.name}" dataField="#{monthWisePieUpdate.noUpdates}" height="200" width="200"/> <h:outputText id="resourceWiseMonthPieChartText" rendered="#{systemUtilizationServiceBean.resourceFlag}" value="Resource Wise Month Update"/> <p:pieChart id="resourceWiseMonthUpdatePieChart" rendered="#{systemUtilizationServiceBean.resourceFlag}" value="#{systemUtilizationServiceBean.monthUpdateCounts}" var="monthWiseResourcePieUpdate" categoryField="#{monthWiseResourcePieUpdate.name}" dataField="#{monthWiseResourcePieUpdate.noUpdates}" height="200" width="200"/> </p:panel> </center> </p:tab> </p:tabView> What should be the reason behind this ?

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  • Find location using only distance and bearing?

    - by pinnacler
    Triangulation works by checking your angle to three KNOWN targets. "I know the that's the Lighthouse of Alexandria, it's located here (X,Y) on a map, and it's to my right at 90 degrees." Repeat 2 more times for different targets and angles. Trilateration works by checking your distance from three KNOWN targets. "I know the that's the Lighthouse of Alexandria, it's located here (X,Y) on a map, and I'm 100 meters away from that." Repeat 2 more times for different targets and ranges. But both of those methods rely on knowing WHAT you're looking at. Say you're in a forest and you can't differentiate between trees, but you know where key trees are. These trees have been hand picked as "landmarks." You have a robot moving through that forest slowly. Do you know of any ways to determine location based solely off of angle and range, exploiting geometry between landmarks? Note, you will see other trees as well, so you won't know which trees are key trees. Ignore the fact that a target may be occluded. Our pre-algorithm takes care of that. 1) If this exists, what's it called? I can't find anything. 2) What do you think the odds are of having two identical location 'hits?' I imagine it's fairly rare. 3) If there are two identical location 'hits,' how can I determine my exact location after I move the robot next. (I assume the chances of having 2 occurrences of EXACT angles in a row, after I reposition the robot, would be statistically impossible, barring a forest growing in rows like corn). Would I just calculate the position again and hope for the best? Or would I somehow incorporate my previous position estimate into my next guess? If this exists, I'd like to read about it, and if not, develop it as a side project. I just don't have time to reinvent the wheel right now, nor have the time to implement this from scratch. So if it doesn't exist, I'll have to figure out another way to localize the robot since that's not the aim of this research, if it does, lets hope it's semi-easy.

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