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  • java TrayIcon using image with transparent background

    - by Jack
    I am using the following code to set a tray icon in Windows and Linux. It works wonderful in Windows and works okay in Linux. In Linux (Ubuntu) I have my panel set to be (somewhat) transparent and when I add a GIF (with a transparent background) the background of the icon shows up all grey and ugly (see image, green diamond "!")....Any ideas on how to make the GIF image I am adding "keep" its transparent background? and the image I am using, if you'd like to test: import java.awt.*; import java.awt.event.*; public class TrayFun { static class ShowMessageListener implements ActionListener { TrayIcon trayIcon; String title; String message; TrayIcon.MessageType messageType; ShowMessageListener( TrayIcon trayIcon, String title, String message, TrayIcon.MessageType messageType) { this.trayIcon = trayIcon; this.title = title; this.message = message; this.messageType = messageType; } public void actionPerformed(ActionEvent e) { trayIcon.displayMessage(title, message, messageType); } } public static void main(String args[]) { Runnable runner = new Runnable() { public void run() { if (SystemTray.isSupported()) { final SystemTray tray = SystemTray.getSystemTray(); Image image = Toolkit.getDefaultToolkit().getImage("green_info.png"); PopupMenu popup = new PopupMenu(); final TrayIcon trayIcon = new TrayIcon(image, "The Tip Text", popup); trayIcon.setImageAutoSize(true); MenuItem item = new MenuItem("Close"); item.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { tray.remove(trayIcon); } }); popup.add(item); try { tray.add(trayIcon); } catch (AWTException e) { System.err.println("Can't add to tray"); } } else { System.err.println("Tray unavailable"); } } }; EventQueue.invokeLater(runner); } }

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  • Oracle rownum in db2 - Java data archiving

    - by HonorGod
    I have a data archiving process in java that moves data between db2 and sybase. FYI - This is not done through any import/export process because there are several conditions on each table that are available on run-time and so this process is developed in java. Right now I have single DatabaseReader and DatabaseWriter defined for each source and destination combination so that data is moved in multiple threads. I guess I wanted to expand this further where I can have Multiple DatabaseReaders and Multiple DatabaseWriters defined for each source and destination combination. So, for example if the source data is about 100 rows and I defined 10 readers and 10 writer, each reader will read 10 rows and give them to the writer. I hope process will give me extreme performance depending on the resources available on the server [CPU, Memory etc]. But I guess the problem is these source tables do not have primary keys and it is extremely difficult to grab rows in multiple sets. Oracle provides rownum concept and i guess the life is much simpler there....but how about db2? How can I achieve this behavior with db2? Is there a way to say fetch first 10 records and then fetch next 10 records and so on? Any suggestions / ideas ? Db2 Version - DB2 v8.1.0.144 Fix Pack Num - 16 Linux

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  • Problem with AssetManager while loading a Model type

    - by user1204548
    Today I've tried the AssetManager for the first time with .g3db files and I'm having some problems. Exception in thread "LWJGL Application" com.badlogic.gdx.utils.GdxRuntimeException: com.badlogic.gdx.utils.GdxRuntimeException: Couldn't load dependencies of asset: data/data at com.badlogic.gdx.assets.AssetManager.handleTaskError(AssetManager.java:508) at com.badlogic.gdx.assets.AssetManager.update(AssetManager.java:342) at com.lostchg.martagdx3d.MartaGame.render(MartaGame.java:78) at com.badlogic.gdx.Game.render(Game.java:46) at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:207) at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:114) Caused by: com.badlogic.gdx.utils.GdxRuntimeException: Couldn't load dependencies of asset: data/data at com.badlogic.gdx.assets.AssetLoadingTask.handleAsyncLoader(AssetLoadingTask.java:119) at com.badlogic.gdx.assets.AssetLoadingTask.update(AssetLoadingTask.java:89) at com.badlogic.gdx.assets.AssetManager.updateTask(AssetManager.java:445) at com.badlogic.gdx.assets.AssetManager.update(AssetManager.java:340) ... 4 more Caused by: com.badlogic.gdx.utils.GdxRuntimeException: com.badlogic.gdx.utils.GdxRuntimeException: Couldn't load file: data/data at com.badlogic.gdx.utils.async.AsyncResult.get(AsyncResult.java:31) at com.badlogic.gdx.assets.AssetLoadingTask.handleAsyncLoader(AssetLoadingTask.java:117) ... 7 more Caused by: com.badlogic.gdx.utils.GdxRuntimeException: Couldn't load file: data/data at com.badlogic.gdx.graphics.Pixmap.<init>(Pixmap.java:140) at com.badlogic.gdx.assets.loaders.TextureLoader.loadAsync(TextureLoader.java:72) at com.badlogic.gdx.assets.loaders.TextureLoader.loadAsync(TextureLoader.java:41) at com.badlogic.gdx.assets.AssetLoadingTask.call(AssetLoadingTask.java:69) at com.badlogic.gdx.assets.AssetLoadingTask.call(AssetLoadingTask.java:34) at com.badlogic.gdx.utils.async.AsyncExecutor$2.call(AsyncExecutor.java:49) at java.util.concurrent.FutureTask.run(Unknown Source) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source) Caused by: com.badlogic.gdx.utils.GdxRuntimeException: File not found: data\data (Internal) at com.badlogic.gdx.files.FileHandle.read(FileHandle.java:132) at com.badlogic.gdx.files.FileHandle.length(FileHandle.java:586) at com.badlogic.gdx.files.FileHandle.readBytes(FileHandle.java:220) at com.badlogic.gdx.graphics.Pixmap.<init>(Pixmap.java:137) ... 9 more Why it tries to load that unexisting file? It seems that the AssetManager manages to load my .g3db file at first, because earlier the java console threw some errors related to the textures associated to the 3D scene having to be a power of 2. Relevant code: public void show() { ... assets = new AssetManager(); assets.load("data/levelprueba2.g3db", Model.class); loading = true; ... } private void doneLoading() { Model model = assets.get("data/levelprueba2.g3db", Model.class); for (int i = 0; i < model.nodes.size; i++) { String id = model.nodes.get(i).id; ModelInstance instance = new ModelInstance(model, id); Node node = instance.getNode(id); instance.transform.set(node.globalTransform); node.translation.set(0,0,0); node.scale.set(1,1,1); node.rotation.idt(); instance.calculateTransforms(); instances.add(instance); } loading = false; } public void render(float delta) { super.render(delta); if (loading && assets.update()) doneLoading(); ... } The error points to the line with the assets.update() method. Please, help! Sorry for my bad English and my amateurish doubts.

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  • sample java code for approximate string matching or boyer-moore extended for approximate string matc

    - by Dolphin
    Hi I need to find 1.mismatch(incorrectly played notes), 2.insertion(additional played), & 3.deletion (missed notes), in a music piece (e.g. note pitches [string values] stored in a table) against a reference music piece. This is either possible through exact string matching algorithms or dynamic programming/ approximate string matching algos. However I realised that approximate string matching is more appropriate for my problem due to identifying mismatch, insertion, deletion of notes. Or an extended version of Boyer-moore to support approx. string matching. Is there any link for sample java code I can try out approximate string matching? I find complex explanations and equations - but I hope I could do well with some sample code and simple explanations. Or can I find any sample java code on boyer-moore extended for approx. string matching? I understand the boyer-moore concept, but having troubles with adjusting it to support approx. string matching (i.e. to support mismatch, insertion, deletion). Also what is the most efficient approx. string matching algorithm (like boyer-moore in exact string matching algo)? Greatly appreciate any insight/ suggestions. Many thanks in advance

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  • Java OutOfMemoryError due to Linux RAM disk cache not freed

    - by Markus Jevring
    The process will run fine all day, then, bam, without warning, it will throw this error. Sometimes seemingly in the middle of doing nothing. It will happen at seemingly random times during the day. I checked to see if anything else was running on the machine, like scheduled backups or something, but found nothing. The machine has enough physical memory (2GB, with about 1GB free for a 3-500MB load), and has sufficient -Xmx specified. According to our sysadmin, the problem is that the RAM that the kernel uses as a disk cache (apparently all but 8MB) is not freed when the JVM needs to allocate memory, so the JVM process throws an OutOfMemoryError. This could be because Java asks the kernel if enough memory is available before allocating and finds that it is insufficient, resulting in a crash. I would like to think, however, that Java simply tries to allocate the memory via the kernel, and when the kernel gets such a request, it makes room for the application by throwing our some of the disk cache. Has anyone else run in to the issue, and if so, what was the error, and how did you solve it? We are currently using jdk1.6.0_20 on SLES 10 SP2 Linux 2.6.16.60-0.42.9-smp in VMWare ESX.

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  • Selecting a Java framework for large application w/ only ONE user

    - by Bijan
    I am building a large application that will be hosted on an AWS server. I'm trying to select a web framework for assisting me with code organization, template design, and generally presentation aspects. Here are some points of consideration: Require security/login/user authentication. I may add the ability in the future to allow more than just an administrator to access the web app, but it is not a public facing website. AJAX support would be helpful. There are a couple widgets that I don't want to recreate. One is a tree object, where the user can expand/contract items in the list, can create new branches, add/edit objects. This would be better off in some dynamic view rather than all done in ugly html. Generally, this is just to provide the application with a face for control, management, and monitoring. Having an easier time adding buttons, CSS, AJAX widgets are great additions though, but not the primary purpose. I'm considering: Wicket Spring Seam GWT Stripe and the list goes on, as I'm sure you all know. I originally planned on using GWT, but then started to feel that GWT didn't cover my primary needs. I could be wrong about this, but there seems to be a lot of support for GWT AND Wicket/Spring. All of this 'getting lost in java frameworks' got me thinking outside the java realm for a framework that would suit my needs that was a clear option, like: JRuby/Rails Jython/Django Groovy/Grails Guice (just throwing this in there... I don't clearly understand the main purposes of all these frameworks. It doesn't seem like DInjection is something I need for a single purpose application) Thanks as always. This community makes Googling for esoteric programming information an order of magnitude better.

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  • Vote on Pros and Cons of Java HTML to XML cleaners

    - by George Bailey
    I am looking to allow HTML emails (and other HTML uploads) without letting in scripts and stuff. I plan to have a white list of safe tags and attributes as well as a whitelist of CSS tags and value regexes (to prevent automatic return receipt). I asked a question: Parse a badly formatted XML document (like an HTML file) I found there are many many ways to do this. Some systems have built in sanitizers (which I don't care so much about). This page is a very nice listing page but I get kinda lost http://java-source.net/open-source/html-parsers It is very important that the parsers never throw an exception. There should always be best guess results to the parse/clean. It is also very important that the result is valid XML that can be traversed in Java. I posted some product information and said Community Wiki. Please post any other product suggestions you like and say Community Wiki so they can be voted on. Also any comments or wiki edits on what part of a certain product is better and what is not would be greatly appreciated. (for example,, speed vs accuracy..) It seems that we will go with either jsoup (seems more active and up to date) or TagSoup (compatible with JDK4 and been around awhile). A +1 for any of these products would be if they could convert all style sheets into inline style on the elements.

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  • Best way to close nested streams in Java?

    - by dirtyvagabond
    What is considered the best, most comprehensive way to close nested streams in Java? For example, consider the setup: FileOutputStream fos = new FileOutputStream(...) BufferedOS bos = new BufferedOS(fos); ObjectOutputStream oos = new ObjectOutputStream(bos); I understand the close operation needs to be insured (probably by using a finally clause). What I wonder about is, is it necessary to explicitly make sure the nested streams are closed, or is it enough to just make sure to close the outer stream (oos)? One thing I notice, at least dealing with this specific example, is that the inner streams only seem to throw FileNotFoundExceptions. Which would seem to imply that there's not technically a need to worry about closing them if they fail. Here's what a colleague wrote: Technically, if it were implemented right, closing the outermost stream (oos) should be enough. But the implementation seems flawed. Example: BufferedOutputStream inherits close() from FilterOutputStream, which defines it as: 155 public void close() throws IOException { 156 try { 157 flush(); 158 } catch (IOException ignored) { 159 } 160 out.close(); 161 } However, if flush() throws a runtime exception for some reason, then out.close() will never be called. So it seems "safest" (but ugly) to mostly worry about closing FOS, which is keeping the file open. What is considered to be the hands-down best, when-you-absolutely-need-to-be-sure, approach to closing nested streams? And are there any official Java/Sun docs that deal with this in fine detail?

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  • XMLRPC java insert issue

    - by Sanjai Palliyil
    I am trying to insert customer details into OpenERP server using XMLPRC and java. I am able to do an authentication. But when i call the execute method to insert the record by passing the parameters, am getting Exception in thread "main" java.lang.NullPointerException on line res_create = client_1.execute("execute", params_create); Please find my code below res = client.execute("login", params); String url_1 = "http://agilewebdevelopment.net:8514/xmlrpc/object"; XmlRpcClientConfigImpl config_1 = new XmlRpcClientConfigImpl(); try { config_1.setServerURL(new URL(url_1)); } catch (MalformedURLException e) { System.out.println("First"); e.printStackTrace(); } System.out.println(res); HashMap<String, Object> vals = new HashMap<String, Object>(); vals.put("name", "Mantavya Gajjar"); vals.put("ref", "MGA"); XmlRpcClient client_1 = new XmlRpcClient(); client.setConfig(config_1); Object[] params_create = new Object[]{"erp_performance", "1", "admin", "res.partner", "create", vals}; Object res_create = null; try { res_create = client_1.execute("execute", params_create); } catch (XmlRpcException e) { e.printStackTrace(); } Any helps is appreciated

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  • Java Server Client Program I/O Exception

    - by AjayP
    I made this program: http://java.sun.com/docs/books/tutorial/networking/sockets/clientServer.html And it works perfectly if I put the server's hostname as 127.0.0.1 or my computers name (Ajay-PC). However these 2 methods are LAN or local only not internet. So I changed it to my internet ip. 70.128.xxx.xxx etc. But it didn't work. I checked: canyouseeme.org and it said 4444 was CLOSED. So I did a quick port forward. Portforward: Name: My Java Program Start Port: 4444 End Port: 4444 Server IP: 10.0.0.12 <-- (Yeah this is my Local IP I checked) then I tried canyouseeme.org AGAIN: and it said 4444 was OPEN I ran my server client program and it yet to work. So my problem is the client server program is not working on the internet just locally. So something is blocking it and I don't know what. Computer: Windows Vista x64 Norton AntiVirus 2010 Thanks! I'll give best answer or whatever to who ever answers the best ;) :)

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  • String length differs from Javascript to Java code

    - by François P.
    I've got a JSP page with a piece of Javascript validation code which limits to a certain amount of characters on submit. I'm using a <textarea> so I can't simply use a length attribute like in a <input type="text">. I use document.getElementById("text").value.length to get the string length. I'm running Firefox 3.0 on Windows (but I've tested this behavior with IE 6 also). The form gets submitted to a J2EE servlet. In my Java servlet the string length of the parameter is larger than 2000! I've noticed that this can easily be reproduced by adding carriage returns in the <textarea>. I've used Firebug to assert the length of the <textare> and it really is 2000 characters long. On the Java side though, the carriage returns get converted to UNIX style (\r\n, instead of \n), thus the string length differs! Am I missing something obvious here or what ? If not, how would you reliably (cross-platform / browser) make sure that the <textarea> is limited.

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  • Using ServletOutputStream to write very large files in a Java servlet without memory issues

    - by Martin
    I am using IBM Websphere Application Server v6 and Java 1.4 and am trying to write large CSV files to the ServletOutputStream for a user to download. Files are ranging from a 50-750MB at the moment. The smaller files aren't causing too much of a problem but with the larger files it appears that it is being written into the heap which is then causing an OutOfMemory error and bringing down the entire server. These files can only be served out to authenticated users over https which is why I am serving them through a Servlet instead of just sticking them in Apache. The code I am using is (some fluff removed around this): resp.setHeader("Content-length", "" + fileLength); resp.setContentType("application/vnd.ms-excel"); resp.setHeader("Content-Disposition","attachment; filename=\"export.csv\""); FileInputStream inputStream = null; try { inputStream = new FileInputStream(path); byte[] buffer = new byte[1024]; int bytesRead = 0; do { bytesRead = inputStream.read(buffer, offset, buffer.length); resp.getOutputStream().write(buffer, 0, bytesRead); } while (bytesRead == buffer.length); resp.getOutputStream().flush(); } finally { if(inputStream != null) inputStream.close(); } The FileInputStream doesn't seem to be causing a problem as if I write to another file or just remove the write completly the memory usage doesn't appear to be a problem. What I am thinking is that the resp.getOutputStream().write is being stored in memory until the data can be sent through to the client. So the entire file might be read and stored in the resp.getOutputStream() causing my memory issues and crashing! I have tried Buffering these streams and also tried using Channels from java.nio, none of which seems to make any bit of difference to my memory issues. I have also flushed the outputstream once per iteration of the loop and after the loop, which didn't help.

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  • Difficulty setting ArrayList to java.sql.Blob to save in DB using hibernate

    - by me_here
    I'm trying to save a java ArrayList in a database (H2) by setting it as a blob, for retrieval later. If this is a bad approach, please say - I haven't been able to find much information on this area. I have a column of type Blob in the database, and Hibernate maps to this with java.sql.Blob. The code I'm struggling with is: Drawings drawing = new Drawings(); try { ByteArrayOutputStream bos = new ByteArrayOutputStream(); ObjectOutputStream oos = null; oos = new ObjectOutputStream(bos); oos.writeObject(plan.drawingPane21.pointList); byte[] buff = bos.toByteArray(); Blob drawingBlob = null; drawingBlob.setBytes(0, buff); drawing.setDrawingObject(drawingBlob); } catch (Exception e){ System.err.println(e); } The object I'm trying to save into a blob (plan.drawingPane21.pointList) is of type ArrayList<DrawingDot>, DrawingDot being a custom class implementing Serializable. My code is failing on the line drawingBlob.setBytes(0, buff); with a NullPointerException. Help appreciated.

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  • Persisting Joda DateTime instead of Java Date in hibernate

    - by Tauren
    My entities currently contain java Date properties. I'm starting to use Joda Time for date manipulation and calculations quite frequently. This means that I'm constantly having to convert my Dates into Joda DateTime objects and back again. So I was wondering, is there any reason I shouldn't just change my entities to store Joda DateTime objects instead of Java Date objects? Please note that these entities are persisted via Hibernate. I found the jodatime-hibernate project, but I also was reading on the Joda mailing list that it wasn't compatible with newer versions of hibernate. And it seems like it isn't very well maintained. So I'm wondering if it would be best to just continue converting between Date and DateTime, or if it would be wise to start persisting DateTime objects. My concern is being reliant on a poorly maintained library. Edit: Note that one of my objectives is to be better able to store timezone information. Storing just a Date appears to save the date in the local timezone. As my application can be used globally, I need to know the timezone as well. Joda Time Hibernate seems to address this as well in the user guide.

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  • Maven:install jar file during build process

    - by Venkata
    I have got a requirement as follows. I need to run ant build file during maven build process. I need to invoke the build.xml from my pom.xml file. I have done that using maven-antrun-plugin. Now I need to install the ant build generated jar file automatically into my local repository before maven compiles my project source. I tried using build-helper-maven-plugin but it did not help. Either I am doing something wrong, or i am not doing right. Please help. Update Thank you. ant maven tasks worked for me as well. However I am runing into the following exception at the end of the build process. Any help is highly appreciated. org.apache.tools.ant.ExitException: Permission (java.lang.RuntimePermission exitVM) was not granted. at org.apache.tools.ant.types.Permissions$MySM.checkExit(Permissions.java:196) at java.lang.Runtime.exit(Runtime.java:99) at java.lang.System.exit(System.java:275) at org.codehaus.classworlds.Launcher.main(Launcher.java:376) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37) at java.lang.reflect.Method.invoke(Method.java:599) at org.apache.tools.ant.taskdefs.ExecuteJava.run(ExecuteJava.java:217) at org.apache.tools.ant.taskdefs.ExecuteJava.execute(ExecuteJava.java:152) at org.apache.tools.ant.taskdefs.Java.run(Java.java:771) at org.apache.tools.ant.taskdefs.Java.executeJava(Java.java:221) at org.apache.tools.ant.taskdefs.Java.executeJava(Java.java:135) at org.apache.tools.ant.taskdefs.Java.execute(Java.java:108) at org.apache.maven.artifact.ant.Mvn.execute(Mvn.java:81) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37) at java.lang.reflect.Method.invoke(Method.java:599) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.Target.execute(Target.java:390) at org.apache.tools.ant.Target.performTasks(Target.java:411) at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1399) at org.apache.tools.ant.Project.executeTarget(Project.java:1368) at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41) at org.apache.tools.ant.Project.executeTargets(Project.java:1251) at org.apache.tools.ant.Main.runBuild(Main.java:809) at org.apache.tools.ant.Main.startAnt(Main.java:217) at org.apache.tools.ant.launch.Launcher.run(Launcher.java:280) at org.apache.tools.ant.launch.Launcher.main(Launcher.java:109)

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  • Spelling correction for data normalization in Java

    - by dareios
    I am looking for a Java library to do some initial spell checking / data normalization on user generated text content, imagine the interests entered in a Facebook profile. This text will be tokenized at some point (before or after spell correction, whatever works better) and some of it used as keys to search for (exact match). It would be nice to cut down misspellings and the like to produce more matches. It would be even better if the correction would perform well on tokens longer than just one word, e.g. "trinking coffee" would become "drinking coffee" and not "thinking coffee". I found the following Java libraries for doing spelling correction: JAZZY does not seem to be under active development. Also, the dictionary-distance based approach seems inadequate because of the use of non-standard language in social network profiles and multi-word tokens. APACHE LUCENE seems to have a statistical spell checker that should be much more suited. Question here would how to create a good dictionary? (We are not using Lucene otherwise, so there is no existing index.) Any suggestions are welcome!

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  • Java: Handling cookies when logging in with POST

    - by Cris Carter
    I'm having quite some trouble logging in to any site in Java. I'm using the default URLconnection POST request, but I'm unsure how to handle the cookies properly. I tried this guide: http://www.hccp.org/java-net-cookie-how-to.html But couldn't get it working. I've been trying basically for days now, and I really need help if anyone wants to help me. I'll probably be told that it's messy and that I should use a custom library meant for this stuff. I tried downloading one, but wasn't sure how to get it set up and working. I've been trying various things for hours now, and it just won't work. I'd rather do this with a standard URLconnection, but if anyone can help me get another library working that's better for this, that would be great, too. I would really appreciate if someone could post a working source that I could study. What I need is: POST login data to site - Get and store the cookie from the site - use cookie with next URLconnection requests to get logged-in version of the site. Can anyone help me with this? Would be EXTREMELY appreciated. It really does mean a lot. If anyone wants to actually help me out live, please leave an instant-messenger address. Thank you a lot for your time.

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  • Java Collections and Garbage Collector

    - by Anth0
    A little question regarding performance in a Java web app. Let's assume I have a List<Rubrique> listRubriques with ten Rubrique objects. A Rubrique contains one list of products (List<product> listProducts) and one list of clients (List<Client> listClients). What exactly happens in memory if I do this: listRubriques.clear(); listRubriques = null; My point of view would be that, since listRubriques is empty, all my objects previously referenced by this list (including listProducts and listClients) will be garbage collected pretty soon. But since Collection in Java are a little bit tricky and since I have quite performance issues with my app i'm asking the question :) edit : let's assume now that my Client object contains a List<Client>. Therefore, I have kind of a circular reference between my objects. What would happen then if my listRubrique is set to null? This time, my point of view would be that my Client objects will become "unreachable" and might create a memory leak?

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  • JAVA vs .NET - Choice for way to go further [closed]

    - by Sarang
    I have my subject .Net acedemically. I also learned core Java and did a project as well. I took training from a Java firm. Now, as a skill I do have knowledge as both language. But, it is creating a large problem to me that, which field I should chhose? Even if having better OOP fundamentals, will it be easier for me to transfer from one to another in the future ? Please suggest me a way. Also, we do have may technologies available at both side, like JSP, JSF, J2ME, Share Point, SilverLight etc. Which is better as per their reliabity point of view? Which are fast growing and useful technologies used mostly in current IT corporate world ? Are they easier to learn at fresher's point of view? Please answer. Perhaps, this answer may help me mostly to create my way to learn them and go further. Every IT developer, please help to find me my way.

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  • Cannot parse persistence unit from class path resource

    - by Grzegorz S
    so I have this problem in running my Spring WS app which implements JPA ( or should implement..) I have a problem with running a WS, it looks like my Spring context can't find file persistence.xml Which i am able to believe because i did not have generated META-INF folder in my template (which is Maven project template with archetype org.springframework.ws) I have created META-INF manually. Here is the HTTP 500: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'caChainDao' defined in file [E:\STS\vfabric-tc-server-developer-2.7.2.RELEASE\zz\wtpwebapps\FCAWSv4\WEB-INF\classes\pl\famoc\test\ws\db\dao\caChainDao.class]: Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in ServletContext resource [/WEB-INF/spring-ws-servlet.xml]: Invocation of init method failed; nested exception is java.lang.IllegalArgumentException: Cannot parse persistence unit from class path resource [persistence.xml] org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:527) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456) org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294) org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225) org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291) org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193) org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:609) org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:469) org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:631) org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:588) org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:645) org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:508) org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:449) org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:133) javax.servlet.GenericServlet.init(GenericServlet.java:160) org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99) org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1002) org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:585) org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310) java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) java.lang.Thread.run(Thread.java:722) Here it is my persistence.xml <?xml version="1.0" encoding="UTF-8" ?> <persistence xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd" version="2.0" xmlns="http://java.sun.com/xml/ns/persistence"> <persistence-unit name="persistenceUnit" transaction-type="RESOURCE_LOCAL" /> </persistence> here it is where i am looking for it <property name="persistenceXmlLocation" value="classpath:persistence.xml" /> and here it is path to this xml in my classpath: src/main/webapp/META-INF/persistence.xml Could anyone give me a hint what am i missing?

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  • How does Java handle ArrayList refrerences and assignments?

    - by Jonathan
    Hey all- I mostly write in C but am using Java for this project. I want to know what Java is doing here under the hood. ArrayList<Integer> prevRow, currRow; currRow = new ArrayList<Integer>(); for(i =0; i < numRows; i++){ prevRow = currRow; currRow.clear(); currRow.addAll(aBunchOfItems); } Is the prevRow = currRow line copying the list or does prevRow now point to the same list as currRow? If prevRow points to the same list as currRow, I should create a new ArrayList instead of clearing.... private ArrayList<Integer> someFunction(ArrayList<Integer> l){ Collections.sort(l); return l; } main(){ ArrayList<Integer> list = new ArrayList<Integer>(Integer(3), Integer(2), Integer(1)); list = someFunction(list); //Option 1 someFunction(list); //Option 2 } In a similar question, do Option 1 and Option 2 do the same thing in the above code? Thanks- Jonathan

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  • Connection details & timeouts in a java web service client

    - by f1sh
    Hello fellow Coders, I have to implement a webservice client to a given WSDL file. I used the SDK's 'wsimport' tool to create Java classes from the WSDL as well as a class that wrap's the webservice's only method (enhanceAddress(auth, param, address)) into a simple java method. So far, so good. The webservice is functional and returning results correcty. The code looks like this: try { EnhancedAddressList uniservResponse = getWebservicePort().enhanceAddress(m_auth, m_param, uniservAddress); //Where the Port^ is the HTTP Soap 1.2 Endpoint }catch (Throwable e) { throw new AddressValidationException("Error during uniserv webservice request.", e); } The Problem now: I need to get Information about the connection and any error that might occur in order to populate various JMX values (such as COUNT_READ_TIMEOUT, COUNT_CONNECT_TIMEOUT, ...) Unfortunately, the method does not officially throw any Exceptions, so in order to get details about a ConnectException, i need to use getCause() on the ClientTransportException that will be thrown. Even worse: I tried to test the read timeout value, but there is none. I changed the service's location in the wsdl file to post the request to a php script that simply waits forever and does not return. Guess what: The web service client does not time out but waits forever as well (I killed the app after 30+ minutes of waiting). That is not an option for my application as i eventually run out of tcp connections if some of them get 'stuck'. The enhanceAddress(auth, param, address) method is not implemented but annotated with javax.jws.* Annotations, meaning that i cannot see/change/inspect the code that is actually executed. Do i have any option but to throw the whole wsimport/javax.jsw-stuff away and implement my own soap client?

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  • Embedded SQL in OO languages like Java

    - by Steve De Caux
    One of the things that annoys me working with SQL in OO languages is having to define SQL statements in strings. When I used to work on IBM mainframes, the languages used an SQL preprocessor to parse SQL statements out of the native code, so the statements could be written in cleartext SQL without the obfuscation of strings, for instance in Cobol there is a EXEC SQL .... END-EXEC syntax construct that allows pure SQL statements to be embedded in the Cobol code. <pure cobol code, including assignment of value to local variable HOSTVARIABLE> EXEC SQL SELECT COL_A, COL_B, COL_C INTO :COLA, :COLB, :COLC FROM TAB_A WHERE COL_D = :HOSTVARIABLE END_EXEC <more cobol code, variables COLA, COLB, COLC have been set> ...this makes the SQL statement really easy to read & check for errors. Between the EXEC SQL .... END-EXEC tokens there are no constraints on indentation, linebreaking etc., so you can format the SQL statement according to taste. Note that this example is for a single-row select, when a multiple-row resultset is expected, the coding is different (but still v. easy to read). So, taking Java as an example What made the "old COBOL" approach undesirable ? Not only SQL, but system calls could be made much more readable with that approach. Let's call it the embedded foreign language preprocessor approach. Would an embedded foreign language preprocessor for SQL be useful to implement ? Would you see a benefit in being able to write native SQL statements inside java code ? Edit I'm really asking if you think SQL in OO languages is a throwback, and if not then what could be done to make it better.

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  • Documentation for java.util.concurrent.locks.ReentrantReadWriteLock

    - by Andrei Taptunov
    Disclaimer: I'm not very good at Java and just comparing read/writer locks between C# and Java to understand this topic better & decisions behind both implementations. There is JavaDoc about ReentrantReadWriteLock. It states the following about upgrade/downgrade for locks: Lock downgrading ... However, upgrading from a read lock to the write lock is not possible. It also has the following example that shows manual upgrade from read lock to write lock: // Here is a code sketch showing how to exploit reentrancy // to perform lock downgrading after updating a cache void processCachedData() { rwl.readLock().lock(); if (!cacheValid) { // upgrade lock manually #1: rwl.readLock().unlock(); // must unlock first to obtain writelock #2: rwl.writeLock().lock(); if (!cacheValid) { // recheck ... } ... } use(data); rwl.readLock().unlock(); Does it mean that actually the sample from above may not behave correctly in some cases - I mean there is no lock between lines #1 & #2 and underlying structure is exposed to changes from other threads. So it can not be considered as the correct way to upgrade the lock or do I miss something here?

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  • Good patterns for loose coupling in Java?

    - by Eye of Hell
    Hello. I'm new to java, and while reading documentation so far i can't find any good ways for programming with loose coupling between objects. For majority of languages i know (C++, C#, python, javascript) i can manage objects as having 'signals' (notification about something happens/something needed) and 'slots' (method that can be connected to signal and process notification/do some work). In all mentioned languages i can write something like this: Object1 = new Object1Class(); Object2 = new Object2Class(); Connect( Object1.ItemAdded, Object2.OnItemAdded ); Now if object1 calls/emits ItemAdded, the OnItemAdded method of Object2 will be called. Such loose coupling technique is often referred as 'delegates', 'signal-slot' or 'inversion of control'. Compared to interface pattern, technique mentioned don't need to group signals into some interfaces. Any object's methods can be connected to any delegate as long as signatures match ( C++Qt even extends this by allowing only partial signature match ). So i don't need to write additional interface code for each methods / groups of methods, provide default implementation for interface methods not used etc. And i can't see anything like this in Java :(. Maybe i'm looking a wrong way?

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