Search Results

Search found 33297 results on 1332 pages for 'java java ee'.

Page 114/1332 | < Previous Page | 110 111 112 113 114 115 116 117 118 119 120 121  | Next Page >

  • Unique number generation with Java Server Faces

    - by Buddhika Ariyaratne
    I am developing an application for a medical channelling centre where multiple users reserve bookings for doctors with JSF and JPA. A sequence number is unique to the Doctor, Date and Session. I tried to get a unique sequence number from counting the previous bookings and add one, but if two requests comes at the same time, two bookings get the same number causing trouble to functionality. How can I get unique number in this case? Can I use an application wide bean to generate it? (I thought it is not practicle to get the unique number from the database sequence number as there are several doctors, sessions and daily they have to have different booking number.)

    Read the article

  • No Need to Disable Java, Update Instead

    - by Tori Wieldt
    Oracle has just released Security Alert CVE-2012-4681 to address 3 distinct but related vulnerabilities and one security-in-depth issue affecting Java running in desktop browsers.  These vulnerabilities are: CVE-2012-4681, CVE-2012-1682, CVE-2012-3136, and CVE-2012-0547.  These vulnerabilities are not applicable to standalone Java desktop applications or Java running on servers, i.e. these vulnerabilities do not affect any Oracle server based software. Due to the severity of these vulnerabilities, the public disclosure of technical details and the reported exploitation of CVE-2012-4681 "in the wild," Oracle strongly recommends that customers apply the updates provided by this Security Alert as soon as possible.  Developers should download the latest release at http://www.oracle.com/technetwork/java/javase/downloads/index.html   Java users should download the latest release of JRE at http://java.com Windows users can take advantage of the Java Automatic Update to get the latest release JUG leader John Yeary tweeted "I want to take a moment to THANK #Oracle for doing the right thing. Too often people don't say thanks enough when they get it right." Thanks for your thanks.  For More Information Oracle Security Alert for CVE-2012-4681 Change to Java SE 7 and Java SE 6 Update Release Numbers

    Read the article

  • Localized text in Java

    - by Eager Learner
    My requirement is to display localized text messages in a J2EE web application. I know J2EE provides very good support for this. My question is what is the practice followed to have the localized messages stored to be used by the application. If I want to display Japanese / Chinese kind of messages which are not like English like char sets how do we get that messages/text into the properties files or Database tables.

    Read the article

  • Java : fusion approuvée des éditions SE/EE/ME, la gouvernance du langage remaniée, vers plus d'équité ?

    Java : fusion approuvée des comités exécutifs des éditions SE/EE/ME La gouvernance du langage remaniée, vers plus d'équité ? [IMG]http://adiguba.developpez.com/blog/javacup.png[/IMG] Avec quatorze votes favorables et une abstention de Google du comité exécutif (EC) de Java SE/EE, seize Oui et deux abstentions de RIM et AT&T du comité de Java ME, la fusion des comités exécutifs de Java SE (Standard Edition), Java EE (Entreprise Edition) et Java ME (Micro Edition) vient d'être approuvé. Le JCP (Java Community Process) Document passe ainsi à la version 2.9. Le comité exécutif est un groupe de membres qui guide l'évolution de la technologie Java au sein du JCP. Il...

    Read the article

  • How do I stop infinite loop? [closed]

    - by SystemNetworks
    As you see, I have a stack overflow error. I wanted to use a class (goldArmor.java) which has all its own stuffs and uses some booleans, int, double from my main class(play.java). Now I want to call my other class(goldArmor.java) to my main class(play.java). When I press run, it says stackoverflow. How do I fix it? For My goldArmor.java: Play playI = new Play(); This is what I tried: Created another class(connect) to connect from my sub-class to my play.class: goldArmor goldArm = new goldArmor(); THen in my play.java: connect con = new connect();

    Read the article

  • Java invalid stream header Problem

    - by David zsl
    Hi all, im writen a client-server app, and now i´m facing a problem that I dont know how to solve: This is the client: try { Socket socket = new Socket(ip, port); ObjectOutputStream ooos = new ObjectOutputStream(socket .getOutputStream()); SendMessage message = new SendMessage(); message.numDoc = value.numDoc; message.docFreq = value.docFreq; message.queryTerms = query; message.startIndex = startIndex; message.count = count; message.multiple = false; message.ips = null; message.ports = null; message.value = true; message.docFreq = value.docFreq; message.numDoc = value.numDoc; ooos.writeObject(message); ObjectInputStream ois = new ObjectInputStream(socket .getInputStream()); ComConstants mensajeRecibido; Object mensajeAux; String mensa = null; byte[] by = null; do { mensajeAux = ois.readObject(); if (mensajeAux instanceof ComConstants) { System.out.println("Thread by Thread has Search Results"); String test; ByteArrayOutputStream testo = new ByteArrayOutputStream(); mensajeRecibido = (ComConstants) mensajeAux; byte[] wag; testo.write( mensajeRecibido.fileContent, 0, mensajeRecibido.okBytes); wag = testo.toByteArray(); if (by == null) { by = wag; } else { int size = wag.length; System.arraycopy(wag, 0, by, 0, size); } } else { System.err.println("Mensaje no esperado " + mensajeAux.getClass().getName()); break; } } while (!mensajeRecibido.lastMessage); //ByteArrayInputStream bs = new ByteArrayInputStream(by.toByteArray()); // bytes es el byte[] ByteArrayInputStream bs = new ByteArrayInputStream(by); ObjectInputStream is = new ObjectInputStream(bs); QueryWithResult[] unObjetoSerializable = (QueryWithResult[])is.readObject(); is.close(); //AQUI TOCARIA METER EL QUICKSORT XmlConverter xce = new XmlConverter(unObjetoSerializable, startIndex, count); String serializedd = xce.runConverter(); tempFinal = serializedd; ois.close(); socket.close(); } catch (Exception e) { e.printStackTrace(); } i++; } And this is the sender: try { QueryWithResult[] outputLine; Operations op = new Operations(); boolean enviadoUltimo=false; ComConstants mensaje = new ComConstants(); mensaje.queryTerms = query; outputLine = op.processInput(query, value); //String c = new String(); //c = outputLine.toString(); //StringBuffer swa = sw.getBuffer(); ByteArrayOutputStream bs= new ByteArrayOutputStream(); ObjectOutputStream os = new ObjectOutputStream (bs); os.writeObject(outputLine); os.close(); byte[] mybytearray = bs.toByteArray(); ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(mybytearray); BufferedInputStream bis = new BufferedInputStream(byteArrayInputStream); int readed = bis.read(mensaje.fileContent,0,4000); while (readed > -1) { mensaje.okBytes = readed; if (readed < ComConstants.MAX_LENGTH) { mensaje.lastMessage = true; enviadoUltimo=true; } else mensaje.lastMessage = false; oos.writeObject(mensaje); if (mensaje.lastMessage) break; mensaje = new ComConstants(); mensaje.queryTerms = query; readed = bis.read(mensaje.fileContent); } if (enviadoUltimo==false) { mensaje.lastMessage=true; mensaje.okBytes=0; oos.writeObject(mensaje); } oos.close(); } catch (Exception e) { e.printStackTrace(); } } And this is the error log: Thread by Thread has Search Results java.io.StreamCorruptedException: invalid stream header: 20646520 at java.io.ObjectInputStream.readStreamHeader(Unknown Source) at java.io.ObjectInputStream.<init>(Unknown Source) at org.tockit.comunication.ServerThread.enviaFicheroMultiple(ServerThread.java:747) at org.tockit.comunication.ServerThread.run(ServerThread.java:129) at java.lang.Thread.run(Unknown Source) Where at org.tockit.comunication.ServerThread.enviaFicheroMultiple(ServerThread.java:747) is this line ObjectInputStream is = new ObjectInputStream(bs); on the 1st code just after while (!mensajeRecibido.lastMessage); Any ideas?

    Read the article

  • How to Stich to Image objects in Java

    - by Imran
    Hi, I have a scenario in which i`m getting a number of tiles (e.g.12) from my mapping server. Now for buffering and offline functions I need to join them all back again so that we have to deal with 1 single image object instead of 12. I ve tried to do it without JAI my code is below. package imagemerge; import java.awt.*; import java.awt.image.*; import java.awt.event.*; public class ImageSticher extends WindowAdapter { Image tile1; Image tile2; Image result; ColorModel colorModel; int width,height,widthr,heightr; //int t1,t2; int t12[]; public ImageSticher() { } public ImageSticher (Image img1,Image img2,int w,int h) { tile1=img1; tile2=img2; width=w; height=h; colorModel=ColorModel.getRGBdefault(); } public Image horizontalStich() throws Exception { widthr=width*2; heightr=height; t12=new int[widthr * heightr]; int t1[]=new int[width*height]; PixelGrabber p1 =new PixelGrabber(tile1, 0, 0, width, height, t1, 0, width); p1.grabPixels(); int t2[]=new int[width*height]; PixelGrabber p2 =new PixelGrabber(tile2, 0, 0, width, height, t1, 0, width); p2.grabPixels(); int y, x, rp, rpi; int red1, red2, redr; int green1, green2, greenr; int blue1, blue2, bluer; int alpha1, alpha2, alphar; for(y=0;y<heightr;y++) { for(x=0;x<widthr;x++) { //System.out.println(x); rpi=y*widthr+x; // index of resulting pixel; rp=0; //initializing resulting pixel System.out.println(rpi); if(x<(widthr/2)) // x is less than width , copy first tile { //System.out.println("tile1="+x); blue1 = t1[rpi] & 0x00ff; // ERROR occurs here green1=(t1[rpi] >> 8) & 0x00ff; red1=(t1[rpi] >> 16) & 0x00ff; alpha1 = (t1[rpi] >> 24) & 0x00ff; redr = (int)(red1 * 1.0); // copying red band pixel into redresult,,,,1.0 is the alpha valye redr = (redr < 0)?(0):((redr>255)?(255):(redr)); greenr = (int)(green1 * 1.0); // redr = (int)(red1 * 1.0); // greenr = (greenr < 0)?(0):((greenr>255)?(255):(greenr)); bluer = (int)(blue1 * 1.0); bluer = (bluer < 0)?(0):((bluer>255)?(255):(bluer)); alphar = 255; //resulting pixel computed rp = (((((alphar << 8) + (redr & 0x0ff)) << 8) + (greenr & 0x0ff)) << 8) + (bluer & 0x0ff); } else // index is ahead of half way...copy second tile { blue2 = t2[rpi] & 0x00ff; // blue band bit of first tile green2=(t2[rpi] >> 8) & 0x00ff; red2=(t2[rpi] >> 16) & 0x00ff; alpha2 = (t2[rpi] >> 24) & 0x00ff; redr = (int)(red2 * 1.0); // copying red band pixel into redresult,,,,1.0 is the alpha valye redr = (redr < 0)?(0):((redr>255)?(255):(redr)); greenr = (int)(green2 * 1.0); // redr = (int)(red2 * 1.0); // greenr = (greenr < 0)?(0):((greenr>255)?(255):(greenr)); bluer = (int)(blue2 * 1.0); bluer = (bluer < 0)?(0):((bluer>255)?(255):(bluer)); alphar = 255; //resulting pixel computed rp = (((((alphar << 8) + (redr & 0x0ff)) << 8) + (greenr & 0x0ff)) << 8) + (bluer & 0x0ff); } t12[rpi] = rp; // copying resulting pixel in the result int array which will be converted to image } } MemoryImageSource mis; if (t12!=null) { mis = new MemoryImageSource(widthr, heightr, colorModel, t12, 0, widthr); result = Toolkit.getDefaultToolkit().createImage(mis); return result; } return null; } } now to check the my theory Im trying to join or stich two tiles horizontaly but im getting the error : java.lang.ArrayIndexOutOfBoundsException: 90000 at imagemerge.ImageSticher.horizontalStich(ImageSticher.java:69) at imageStream.ImageStream.getImage(ImageStream.java:75) at imageStream.ImageStream.main(ImageStream.java:28) is there some kind of limitation because when stiching two images of 300 x 300 horizontally it means the resulting image will be 600 x 300 ... that would make 180000 index size but its giving error at 90000, what am I doing wrong here

    Read the article

  • Tomcat stops responding to JK requests

    - by Bruno Reis
    Hello. I have a nasty issue with load-balanced Tomcat servers that are hanging up. Any help would be greatly appreciated. The system I'm running Tomcat 6.0.26 on HotSpot Server 14.3-b01 (Java 1.6.0_17-b04) on three servers sitting behind another server that acts as load balancer. The load balancer runs Apache (2.2.8-1) + MOD_JK (1.2.25). All of the servers are running Ubuntu 8.04. The Tomcat's have 2 connectors configured: an AJP one, and a HTTP one. The AJP is to be used with the load balancer, while the HTTP is used by the dev team to directly connect to a chosen server (if we have a reason to do so). I have Lambda Probe 1.7b installed on the Tomcat servers to help me diagnose and fix the problem soon to be described. The problem Here's the problem: after about 1 day the application servers are up, JK Status Manager starts reporting status ERR for, say, Tomcat2. It will simply get stuck on this state, and the only fix I've found so far is to ssh the box and restart Tomcat. I must also mention that JK Status Manager takes a lot longer to refresh when there's a Tomcat server in this state. Finally, the "Busy" count of the stuck Tomcat on JK Status Manager is always high, and won't go down per se -- I must restart the Tomcat server, wait, then reset the worker on JK. Analysis Since I have 2 connectors on each Tomcat (AJP and HTTP), I still can connect to the application through the HTTP one. The application works just fine like this, very, very fast. That is perfectly normal, since I'm the only one using this server (as JK stopped delegating requests to this Tomcat). To try to better understand the problem, I've taken a thread dump from a Tomcat which is not responding anymore, and from another one that has been restarted recently (say, 1 hour before). The instance that is responding normally to JK shows most of the TP-ProcessorXXX threads in "Runnable" state, with the following stack trace: java.net.SocketInputStream.socketRead0 ( native code ) java.net.SocketInputStream.read ( SocketInputStream.java:129 ) java.io.BufferedInputStream.fill ( BufferedInputStream.java:218 ) java.io.BufferedInputStream.read1 ( BufferedInputStream.java:258 ) java.io.BufferedInputStream.read ( BufferedInputStream.java:317 ) org.apache.jk.common.ChannelSocket.read ( ChannelSocket.java:621 ) org.apache.jk.common.ChannelSocket.receive ( ChannelSocket.java:559 ) org.apache.jk.common.ChannelSocket.processConnection ( ChannelSocket.java:686 ) org.apache.jk.common.ChannelSocket$SocketConnection.runIt ( ChannelSocket.java:891 ) org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run ( ThreadPool.java:690 ) java.lang.Thread.run ( Thread.java:619 ) The instance that is stuck show most (all?) of the TP-ProcessorXXX threads in "Waiting" state. These have the following stack trace: java.lang.Object.wait ( native code ) java.lang.Object.wait ( Object.java:485 ) org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run ( ThreadPool.java:662 ) java.lang.Thread.run ( Thread.java:619 ) I don't know of the internals of Tomcat, but I would infer that the "Waiting" threads are simply threads sitting on a thread pool. So, if they are threads waiting inside of a thread pool, why wouldn't Tomcat put them to work on processing requests from JK? Solution? So, as I've stated before, the only fix I've found is to stop the Tomcat instance, stop the JK worker, wait the latter's busy count slowly go down, start Tomcat again, and enable the JK worker once again. What is causing this problem? How should I further investigate it? What can I do to solve it? Thanks in advance.

    Read the article

  • Ant + JUnit: NoClassDefFoundError

    - by K-Boo
    Ok, I'm frustrated! I've hunted around for a good number of hours and am still stumped. Environment: WinXP, Eclipse Galileo 3.5 (straight install - no extra plugins). So, I have a simple JUnit test. It runs fine from it's internal Eclipse JUnit run configuration. This class has no dependencies on anything. To narrow this problem down as much as possible it simply contains: @Test public void testX() { assertEquals("1", new Integer(1).toString()); } No sweat so far. Now I want to take the super advanced step of running this test case from within Ant (the final goal is to integrate with Hudson). So, I create a build.xml: <project name="Test" default="basic"> <property name="default.target.dir" value="${basedir}/target" /> <property name="test.report.dir" value="${default.target.dir}/test-reports" /> <target name="basic"> <mkdir dir="${test.report.dir}" /> <junit fork="true" printSummary="true" showOutput="true"> <formatter type="plain" /> <classpath> <pathelement path="${basedir}/bin "/> </classpath> <batchtest fork="true" todir="${test.report.dir}" > <fileset dir="${basedir}/bin"> <include name="**/*Test.*" /> </fileset> </batchtest> </junit> </target> </project> ${basedir} is the Java project name in the workspace that contains the source, classes and build file. All .java's and the build.xml are in ${basedir}/src. The .class files are in ${basedir}/bin. I have added eclipse-install-dir/plugins/org.junit4_4.5.0.v20090423/junit.jar to the Ant Runtime Classpath via Windows / Preferences / Ant / Runtime / Contributed Entries. ant-junit.jar is in Ant Home Entries. So, what happens when I run this insanely complex target? My report file contains: Testsuite: com.xyz.test.RussianTest Tests run: 1, Failures: 0, Errors: 1, Time elapsed: 0 sec Testcase: initializationError took 0 sec Caused an ERROR org/hamcrest/SelfDescribing java.lang.NoClassDefFoundError: org/hamcrest/SelfDescribing at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(Unknown Source) at java.security.SecureClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.access$000(Unknown Source) at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClassInternal(Unknown Source) at java.lang.reflect.Constructor.newInstance(Unknown Source) Caused by: java.lang.ClassNotFoundException: org.hamcrest.SelfDescribing at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClassInternal(Unknown Source) What is this org.hamcrest.SelfDescribing class? Something to do with mocks? OK, fine. But why the dependency? I'm not doing anything at all with it. This is literally a Java project with no dependencies other than JUnit. Stumped (and frustrated)!!

    Read the article

  • Android Activity ClassNotFoundException - tried everything

    - by Matthew Rathbone
    I've just refactored an app into a framework library and an application, but now when I try and start the app in the emulator I get the following error stack trace: 06-02 18:22:35.529: E/AndroidRuntime(586): FATAL EXCEPTION: main 06-02 18:22:35.529: E/AndroidRuntime(586): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.matthewrathbone.eastersays/com.matthewrathbone.eastersays.EasterSimonSaysActivity}: java.lang.ClassNotFoundException: com.matthewrathbone.eastersays.EasterSimonSaysActivity in loader dalvik.system.PathClassLoader[/data/app/com.matthewrathbone.eastersays-1.apk] 06-02 18:22:35.529: E/AndroidRuntime(586): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2585) 06-02 18:22:35.529: E/AndroidRuntime(586): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 06-02 18:22:35.529: E/AndroidRuntime(586): at android.app.ActivityThread.access$2300(ActivityThread.java:125) 06-02 18:22:35.529: E/AndroidRuntime(586): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 06-02 18:22:35.529: E/AndroidRuntime(586): at android.os.Handler.dispatchMessage(Handler.java:99) 06-02 18:22:35.529: E/AndroidRuntime(586): at android.os.Looper.loop(Looper.java:123) 06-02 18:22:35.529: E/AndroidRuntime(586): at android.app.ActivityThread.main(ActivityThread.java:4627) 06-02 18:22:35.529: E/AndroidRuntime(586): at java.lang.reflect.Method.invokeNative(Native Method) 06-02 18:22:35.529: E/AndroidRuntime(586): at java.lang.reflect.Method.invoke(Method.java:521) 06-02 18:22:35.529: E/AndroidRuntime(586): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 06-02 18:22:35.529: E/AndroidRuntime(586): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 06-02 18:22:35.529: E/AndroidRuntime(586): at dalvik.system.NativeStart.main(Native Method) 06-02 18:22:35.529: E/AndroidRuntime(586): Caused by: java.lang.ClassNotFoundException: com.matthewrathbone.eastersays.EasterSimonSaysActivity in loader dalvik.system.PathClassLoader[/data/app/com.matthewrathbone.eastersays-1.apk] 06-02 18:22:35.529: E/AndroidRuntime(586): at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:243) 06-02 18:22:35.529: E/AndroidRuntime(586): at java.lang.ClassLoader.loadClass(ClassLoader.java:573) 06-02 18:22:35.529: E/AndroidRuntime(586): at java.lang.ClassLoader.loadClass(ClassLoader.java:532) 06-02 18:22:35.529: E/AndroidRuntime(586): at android.app.Instrumentation.newActivity(Instrumentation.java:1021) 06-02 18:22:35.529: E/AndroidRuntime(586): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2577) 06-02 18:22:35.529: E/AndroidRuntime(586): ... 11 more Usually this means that the manifest file is wrong in some way, but I've double checked everything I can think of. Here is my activity class: package com.matthewrathbone.eastersays; import android.os.Bundle; import com.rathboma.simonsays.Assets.Season; import com.rathboma.simonsays.SeasonPicker; import com.rathboma.simonsays.SimonSaysActivity; public class EasterSimonSaysActivity extends SimonSaysActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); } @Override protected void onDestroy() { // TODO Auto-generated method stub super.onDestroy(); } @Override public SeasonPicker getSeasonPicker() { return new SeasonPicker(){ @Override public Season getSeason() { // TODO Auto-generated method stub return Season.EASTER; } }; } } As you can see, it's listed correctly in the manifest: <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.matthewrathbone.eastersays" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="7" android:targetSdkVersion="15" /> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" > <activity android:name=".EasterSimonSaysActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest> I have no idea how to fix this, and would appreciate any help. I've scanned many similar questions on SO without seeing this particular behavior. More info: I've checked inside the generated APK and the class has an entry in the classes.dex file I've tried cleaning/building the project in eclipse I've tried using a totally new device image that doesn't have a copy of the APK on it already I've changed the library project into a regular java, then changed back into an android project, no difference

    Read the article

  • How to determine errors in java

    - by user225269
    I'm just a java beginner. Do you have any tips there on how to determine errors. I'm trying to connect to mysql derby database. I don't know how to determine the error, there is no red line, but there is a message box that shows up when I try to run the program. All I want to do is to display the first record in the database. All I get is this in the output: E:\Users\users.netbeans\6.8\var\cache\executor-snippets\run.xml:45: package Employees; import java.sql.Statement; import javax.swing.JOptionPane; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; import java.sql.ResultSet; /** * * @author Nrew */ public class Students extends javax.swing.JFrame { Connection con; Statement stmt; ResultSet rs; /** Creates new form Students */ public Students() { initComponents(); DoConnect(); } public void DoConnect(){ try { String host= "jdbc:derby://localhost:1527/YURA"; String uname = "bart"; String pword = "12345"; con = DriverManager.getConnection(host, uname, pword); stmt = con.createStatement( ); String SQL = "SELECT * FROM APP.XROSS"; rs = stmt.executeQuery(SQL); rs.next(); rs.next( ); int ids = rs.getInt("IDNUM"); String idz = Integer.toString(ids); String fname = rs.getString("FNAME"); String lname = rs.getString("LNAME"); String course = rs.getString("COURSE"); String skul = rs.getString("SCHOOL"); String gen = rs.getString("GENDER"); TextIDNUM.setText(idz); TextFNAME.setText(fname); TextLNAME.setText(lname); textCOURSE.setText(course); textSCHOOL.setText(skul); textGENDER.setText(gen); } catch (SQLException err) { JOptionPane.showMessageDialog(Students.this, err.getMessage()); } } /** This method is called from within the constructor to * initialize the form. * WARNING: Do NOT modify this code. The content of this method is * always regenerated by the Form Editor. */ @SuppressWarnings("unchecked") // <editor-fold defaultstate="collapsed" desc="Generated Code"> private void initComponents() { TextIDNUM = new javax.swing.JTextField(); TextFNAME = new javax.swing.JTextField(); TextLNAME = new javax.swing.JTextField(); textCOURSE = new javax.swing.JTextField(); textSCHOOL = new javax.swing.JTextField(); textGENDER = new javax.swing.JTextField(); setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane()); getContentPane().setLayout(layout); layout.setHorizontalGroup( layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGap(116, 116, 116) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false) .addComponent(textGENDER, javax.swing.GroupLayout.Alignment.LEADING) .addComponent(textSCHOOL, javax.swing.GroupLayout.Alignment.LEADING) .addComponent(textCOURSE, javax.swing.GroupLayout.Alignment.LEADING) .addComponent(TextLNAME, javax.swing.GroupLayout.Alignment.LEADING) .addComponent(TextFNAME, javax.swing.GroupLayout.Alignment.LEADING) .addComponent(TextIDNUM, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 151, Short.MAX_VALUE)) .addContainerGap(243, Short.MAX_VALUE)) ); layout.setVerticalGroup( layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGap(37, 37, 37) .addComponent(TextIDNUM, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addGap(18, 18, 18) .addComponent(TextFNAME, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addGap(18, 18, 18) .addComponent(TextLNAME, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addGap(18, 18, 18) .addComponent(textCOURSE, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED) .addComponent(textSCHOOL, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED) .addComponent(textGENDER, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addContainerGap(67, Short.MAX_VALUE)) ); pack(); }// </editor-fold> /** * @param args the command line arguments */ public static void main(String args[]) { java.awt.EventQueue.invokeLater(new Runnable() { public void run() { new Students().setVisible(true); } }); } // Variables declaration - do not modify private javax.swing.JTextField TextFNAME; private javax.swing.JTextField TextIDNUM; private javax.swing.JTextField TextLNAME; private javax.swing.JTextField textCOURSE; private javax.swing.JTextField textGENDER; private javax.swing.JTextField textSCHOOL; // End of variables declaration }

    Read the article

  • Android: Showing photos runs out of memory

    - by Tom Beech
    I'm using a dialog box to display images in my android project. The first one opens fine, but when I close it and do the process again to show a different one the app falls over with a memory error (it's running on a samsung galaxy s3 - so shouldnt be an issue). Error: 10-24 11:25:45.575: E/dalvikvm-heap(29194): Out of memory on a 31961104-byte allocation. 10-24 11:25:45.580: E/AndroidRuntime(29194): FATAL EXCEPTION: main 10-24 11:25:45.580: E/AndroidRuntime(29194): java.lang.OutOfMemoryError 10-24 11:25:45.580: E/AndroidRuntime(29194): at android.graphics.BitmapFactory.nativeDecodeStream(Native Method) 10-24 11:25:45.580: E/AndroidRuntime(29194): at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:587) 10-24 11:25:45.580: E/AndroidRuntime(29194): at android.graphics.BitmapFactory.decodeFile(BitmapFactory.java:389) 10-24 11:25:45.580: E/AndroidRuntime(29194): at android.graphics.BitmapFactory.decodeFile(BitmapFactory.java:418) 10-24 11:25:45.580: E/AndroidRuntime(29194): at android.graphics.drawable.Drawable.createFromPath(Drawable.java:882) 10-24 11:25:45.580: E/AndroidRuntime(29194): at android.widget.ImageView.resolveUri(ImageView.java:569) 10-24 11:25:45.580: E/AndroidRuntime(29194): at android.widget.ImageView.setImageURI(ImageView.java:340) 10-24 11:25:45.580: E/AndroidRuntime(29194): at com.directenquiries.assessment.tool.AddAsset.loadPhoto(AddAsset.java:771) 10-24 11:25:45.580: E/AndroidRuntime(29194): at com.directenquiries.assessment.tool.AddAsset$11.onClick(AddAsset.java:748) 10-24 11:25:45.580: E/AndroidRuntime(29194): at com.android.internal.app.AlertController$AlertParams$3.onItemClick(AlertController.java:936) 10-24 11:25:45.580: E/AndroidRuntime(29194): at android.widget.AdapterView.performItemClick(AdapterView.java:292) 10-24 11:25:45.580: E/AndroidRuntime(29194): at android.widget.AbsListView.performItemClick(AbsListView.java:1359) 10-24 11:25:45.580: E/AndroidRuntime(29194): at android.widget.AbsListView$PerformClick.run(AbsListView.java:2988) 10-24 11:25:45.580: E/AndroidRuntime(29194): at android.widget.AbsListView$1.run(AbsListView.java:3783) 10-24 11:25:45.580: E/AndroidRuntime(29194): at android.os.Handler.handleCallback(Handler.java:605) 10-24 11:25:45.580: E/AndroidRuntime(29194): at android.os.Handler.dispatchMessage(Handler.java:92) 10-24 11:25:45.580: E/AndroidRuntime(29194): at android.os.Looper.loop(Looper.java:137) 10-24 11:25:45.580: E/AndroidRuntime(29194): at android.app.ActivityThread.main(ActivityThread.java:4517) 10-24 11:25:45.580: E/AndroidRuntime(29194): at java.lang.reflect.Method.invokeNative(Native Method) 10-24 11:25:45.580: E/AndroidRuntime(29194): at java.lang.reflect.Method.invoke(Method.java:511) 10-24 11:25:45.580: E/AndroidRuntime(29194): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993) 10-24 11:25:45.580: E/AndroidRuntime(29194): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760) 10-24 11:25:45.580: E/AndroidRuntime(29194): at dalvik.system.NativeStart.main(Native Method) Loading code: public void loadPhotoList(){ Cursor f = db.rawQuery("select * from stationphotos where StationObjectID = '"+ checkStationObjectID + "'", null); final ArrayList<String> mHelperNames= new ArrayList<String>(); if(f.getCount() != 0) { f.moveToFirst(); f.moveToFirst(); while(!f.isAfterLast()) { mHelperNames.add(f.getString(f.getColumnIndex("FilePath"))); f.moveToNext(); } } f.close(); final String [] nameStrings = new String [mHelperNames.size()]; for(int i=0; i<mHelperNames.size(); i++) nameStrings[i] = mHelperNames.get(i).toString(); AlertDialog.Builder builder = new AlertDialog.Builder(this); builder.setTitle("Select Picture"); builder.setItems(nameStrings, new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int item) { loadPhoto(mHelperNames.get(item).toString()); } }); AlertDialog alert = builder.create(); alert.show(); } public void loadPhoto(String imagepath){ Dialog dialog = new Dialog(this); dialog.setContentView(R.layout.activity_show_image); dialog.setTitle("Image"); dialog.setCancelable(true); ImageView img = (ImageView) dialog.findViewById(R.id.imageView1); img.setImageResource(R.drawable.ico_partial); Uri imgUri = Uri.parse(imagepath); img.setImageURI(imgUri); dialog.show(); }

    Read the article

  • How to determine the exact java executable that a running app is using?

    - by kjo
    Suppose I click on a java app's icon, and the app starts normally. How can I find out the path to the java executable that is running the app? Better yet, is there a way to find the exact command-line invocation of java that would have the same effect as double-clicking on the icon? (Note: I'm aware of open -a, and it is definitely not what I'm asking about here. The command-line invocation I'm interested in should begin with java ..., specify a classpath, etc.)

    Read the article

  • Android "application stopped unexpectedly" - google Hello MapView Tutoria

    - by Cookie
    Hi, I'm trying the Hello MapView Tutorial at the moment. Whe I launch the program in the emulator, I get a huge number of errors (none of the exceptions seems to be related with lines in my code). The emulator window tells the program "stopped unexpectedly". Can anybody tell me which is the key line in the error output? What do I have to change? 05-02 15:04:57.195: ERROR/vold(26): Error opening switch name path '/sys/class/switch/test2' (No such file or directory) 05-02 15:04:57.195: ERROR/vold(26): Error bootstrapping switch '/sys/class/switch/test2' (No such file or directory) 05-02 15:04:57.195: ERROR/vold(26): Error opening switch name path '/sys/class/switch/test' (No such file or directory) 05-02 15:04:57.195: ERROR/vold(26): Error bootstrapping switch '/sys/class/switch/test' (No such file or directory) 05-02 15:05:10.659: ERROR/MemoryHeapBase(51): error opening /dev/pmem: No such file or directory 05-02 15:05:10.659: ERROR/SurfaceFlinger(51): Couldn't open /sys/power/wait_for_fb_sleep or /sys/power/wait_for_fb_wake 05-02 15:05:10.699: ERROR/libEGL(51): couldn't load <libhgl.so> library (Cannot load library: load_library[984]: Library 'libhgl.so' not found) 05-02 15:05:11.403: ERROR/libEGL(62): couldn't load <libhgl.so> library (Cannot load library: load_library[984]: Library 'libhgl.so' not found) 05-02 15:05:14.775: ERROR/BatteryService(51): Could not open '/sys/class/power_supply/usb/online' 05-02 15:05:14.775: ERROR/BatteryService(51): Could not open '/sys/class/power_supply/battery/batt_vol' 05-02 15:05:14.775: ERROR/BatteryService(51): Could not open '/sys/class/power_supply/battery/batt_temp' 05-02 15:05:15.148: ERROR/EventHub(51): could not get driver version for /dev/input/mouse0, Not a typewriter 05-02 15:05:15.148: ERROR/EventHub(51): could not get driver version for /dev/input/mice, Not a typewriter 05-02 15:05:15.282: ERROR/System(51): Failure starting core service 05-02 15:05:15.282: ERROR/System(51): java.lang.SecurityException 05-02 15:05:15.282: ERROR/System(51): at android.os.BinderProxy.transact(Native Method) 05-02 15:05:15.282: ERROR/System(51): at android.os.ServiceManagerProxy.addService(ServiceManagerNative.java:146) 05-02 15:05:15.282: ERROR/System(51): at android.os.ServiceManager.addService(ServiceManager.java:72) 05-02 15:05:15.282: ERROR/System(51): at com.android.server.ServerThread.run(SystemServer.java:162) 05-02 15:05:15.302: ERROR/AndroidRuntime(51): Crash logging skipped, no checkin service 05-02 15:05:17.012: ERROR/LockPatternKeyguardView(51): Failed to bind to GLS while checking for account 05-02 15:05:21.795: ERROR/ActivityThread(100): Failed to find provider info for com.google.settings 05-02 15:05:21.819: ERROR/ActivityThread(100): Failed to find provider info for com.google.settings 05-02 15:05:25.872: ERROR/ApplicationContext(51): Couldn't create directory for SharedPreferences file shared_prefs/wallpaper-hints.xml 05-02 15:05:28.923: ERROR/vold(26): Cannot start volume '/sdcard' (volume is not bound) 05-02 15:05:26.879: ERROR/ActivityThread(97): Failed to find provider info for android.server.checkin 05-02 15:05:30.211: ERROR/ActivityThread(97): Failed to find provider info for android.server.checkin 05-02 15:05:30.430: ERROR/ActivityThread(97): Failed to find provider info for android.server.checkin 05-02 15:05:32.463: ERROR/MediaPlayerService(30): Couldn't open fd for content://settings/system/notification_sound 05-02 15:05:32.489: ERROR/MediaPlayer(51): Unable to to create media player 05-02 15:05:34.783: ERROR/ActivityThread(51): Failed to find provider info for com.google.settings 05-02 15:05:34.783: ERROR/ActivityThread(51): Failed to find provider info for com.google.settings 05-02 15:05:35.359: ERROR/AndroidRuntime(201): Uncaught handler: thread main exiting due to uncaught exception 05-02 15:05:35.395: ERROR/AndroidRuntime(201): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{org.diretto.client.smartphone.android/org.diretto.client.smartphone.android.ShowMap}: java.lang.ClassNotFoundException: org.diretto.client.smartphone.android.ShowMap in loader dalvik.system.PathClassLoader@4376af90 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2324) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2417) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at android.app.ActivityThread.access$2100(ActivityThread.java:116) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1794) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at android.os.Handler.dispatchMessage(Handler.java:99) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at android.os.Looper.loop(Looper.java:123) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at android.app.ActivityThread.main(ActivityThread.java:4203) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at java.lang.reflect.Method.invokeNative(Native Method) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at java.lang.reflect.Method.invoke(Method.java:521) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at dalvik.system.NativeStart.main(Native Method) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): Caused by: java.lang.ClassNotFoundException: org.diretto.client.smartphone.android.ShowMap in loader dalvik.system.PathClassLoader@4376af90 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:243) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at java.lang.ClassLoader.loadClass(ClassLoader.java:573) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at java.lang.ClassLoader.loadClass(ClassLoader.java:532) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at android.app.Instrumentation.newActivity(Instrumentation.java:1097) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2316) 05-02 15:05:35.395: ERROR/AndroidRuntime(201): ... 11 more 05-02 15:05:35.527: ERROR/dalvikvm(201): Unable to open stack trace file '/data/anr/traces.txt': Permission denied

    Read the article

  • Request header is too large

    - by stck777
    I found serveral IllegalStateException Exception in the logs: [#|2009-01-28T14:10:16.050+0100|SEVERE|sun-appserver2.1|javax.enterprise.system.container.web|_ThreadID=26;_ThreadName=httpSSLWorkerThread-80-53;_RequestID=871b8812-7bc5-4ed7-85f1-ea48f760b51e;|WEB0777: Unblocking keep-alive exception java.lang.IllegalStateException: PWC4662: Request header is too large at org.apache.coyote.http11.InternalInputBuffer.fill(InternalInputBuffer.java:740) at org.apache.coyote.http11.InternalInputBuffer.parseHeader(InternalInputBuffer.java:657) at org.apache.coyote.http11.InternalInputBuffer.parseHeaders(InternalInputBuffer.java:543) at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.parseRequest(DefaultProcessorTask.java:712) at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.doProcess(DefaultProcessorTask.java:577) at com.sun.enterprise.web.connector.grizzly.DefaultProcessorTask.process(DefaultProcessorTask.java:831) at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.executeProcessorTask(DefaultReadTask.java:341) at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:263) at com.sun.enterprise.web.connector.grizzly.DefaultReadTask.doTask(DefaultReadTask.java:214) at com.sun.enterprise.web.portunif.PortUnificationPipeline$PUTask.doTask(PortUnificationPipeline.java:380) at com.sun.enterprise.web.connector.grizzly.TaskBase.run(TaskBase.java:265) at com.sun.enterprise.web.connector.grizzly.ssl.SSLWorkerThread.run(SSLWorkerThread.java:106) |#] Does anybody know configuration changes to fix this?

    Read the article

  • ScrollPanel in java does not appear JTextarea resizes instead

    - by Casper Marcussen
    Hello everyone My program is finished, but testing it out, i found out that the scrollpanel does not appear, it just resizes the JTextarea instead. The code is provided below: package javaapplication15; import java.awt.Container; import java.awt.FlowLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.io.*; import java.io.IOException; import javax.swing.*; public class Tekstprogram extends JFrame { public Tekstprogram() { setSize(400, 600); setDefaultCloseOperation(EXIT_ON_CLOSE); setResizable(false); Container Indhold = getContentPane(); Indhold.setLayout(new FlowLayout()); JButton openButton = new JButton("Open"); JButton saveButton = new JButton("Save"); final JLabel statusbar = new JLabel("Output of your selection will go here"); final JTextArea TekstOmråde = new JTextArea(29, 30); JScrollPane scrollText = new JScrollPane(TekstOmråde); openButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent ae) { JFileChooser chooser = new JFileChooser(); chooser.setMultiSelectionEnabled(true); int option = chooser.showOpenDialog(Tekstprogram.this); if (option == JFileChooser.APPROVE_OPTION) { File[] sf = chooser.getSelectedFiles(); String filelist = "nothing"; if (sf.length > 0) { filelist = sf[0].getName(); } for (int i = 1; i < sf.length; i++) { filelist = filelist + ", " + sf[i].getName(); } try { String strLine; File selectedFile = chooser.getSelectedFile(); FileInputStream in = new FileInputStream(selectedFile); BufferedReader br = new BufferedReader(new InputStreamReader(in)); while ((strLine = br.readLine()) != null) { TekstOmråde.append(strLine + "\n"); } } catch (Exception e) { System.out.println("En fejl opstod ved" + e); } } } }); saveButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent ae) { JFileChooser chooser = new JFileChooser(); int option = chooser.showSaveDialog(Tekstprogram.this); if (option == JFileChooser.APPROVE_OPTION) { File file = chooser.getSelectedFile(); try { BufferedWriter out = new BufferedWriter(new FileWriter(file)); out.write(TekstOmråde.getText()); out.close(); } catch (IOException e) { System.out.println("IOException fejl opstod :"); e.printStackTrace(); } } } }); Indhold.add(openButton); Indhold.add(saveButton); Indhold.add(TekstOmråde); Indhold.add(scrollText); Indhold.add(statusbar); } public static void main(String args[]) { Tekstprogram sfc = new Tekstprogram(); sfc.setVisible(true); } } Is there anyway to make the JTexarea static?

    Read the article

  • What's a good open source java project for students to hack on?

    - by Evan Grim
    I'm working with a professor to develop a course teaching practical software development tools and methodology. We're looking for a sample code base that we can use for hands-on experience in each of the topics and as the basis for a semester-long project where students will work in a team to implement a feature or fix bugs. Here are some basic guidelines for the project that we'd like to come close to meeting: java based, ~50K SLOC, uses ant, depends upon some external library, has a test suite (preferably jUnit), friendly for development within eclipse, actively developed with a substantial history available within a version control system (such as subversion), the more "coolness" factor the better (to motivate the students), and preferably with some kind of user interface (e.g.: not just a library).

    Read the article

  • Tab Sweep - More OSGi, Coherence, Oracle Java moves, JMS 2.0 and more

    - by alexismp
    Recent Tips and News on Java, Java EE 6, GlassFish & more : • Why I will use Java EE (JEE, and not J2EE) instead of Spring in new Enterprise Java Projects (Kai) • What is Happening vs. What is Interesting (Geertjan) • Oracle Coherence & Oracle Service Bus: REST API Integration (Nino) • Oracle's Top 10 Java Moves of 2011 (eWeek) • JEP 122: Remove the Permanent Generation (OpenJDK.org) • JEE6 – Glassfish 3.1, Clustering & Failover (Xebia.fr) • Testing LAZY mechanism in EJB 3 (e-blog-java) • Discoing with Vorpal (Chuk) • Devoxx : les évolutions de JMS 2.0 (Ippon.fr) • More OSGi... (Jarda) • Practical Migration to Java 7 - Small Codeexamples (FOSSLC) • Coherence Part III : Filtres (Zenika.com)

    Read the article

  • Is there any reason lazy initialization couldn't be built into Java?

    - by Renesis
    Since I'm working on a server with absolutely no non-persisted state for users, every User-related object we have is rolled out on every request. Consequently I often find myself doing lazy initialization of properties of objects that may go unused. protected EventDispatcher dispatcher = new EventDispatcher(); Becomes... protected EventDispatcher<EventMessage> dispatcher; public EventDispatcher<EventMessage> getEventDispatcher() { if (dispatcher == null) { dispatcher = new EventDispatcher<EventMessage>(); } return dispatcher; } Is there any reason this couldn't be built into Java? protected lazy EventDispatcher dispatcher = new EventDispatcher();

    Read the article

  • What are the downsides of implementing a singleton with Java's enum?

    - by irreputable
    Traditionally, a singleton is usually implemented as public class Foo1 { private static final Foo1 INSTANCE = new Foo1(); public static Foo1 getInstance(){ return INSTANCE; } private Foo1(){} public void doo(){ ... } } With Java's enum, we can implement a singleton as public enum Foo2 { INSTANCE; public void doo(){ ... } } As awesome as the 2nd version is, are there any downsides to it? (I gave it some thoughts and I'll answer my own question; hopefully you have better answers)

    Read the article

  • What is the correct way to handle debug output in Java?

    - by Federico Zancan
    As my current Java projects grow bigger and bigger, I feel a likewise growing need to insert debug output in several points of my code. To enable or disable this feature appropriately, depending on the opening or closure of the test sessions, I usually put a private static final boolean DEBUG = false at the beginning of the classes my tests are inspecting, and trivially use it this way (for example): public MyClass { private static final boolean DEBUG = false; ... some code ... public void myMethod(String s) { if (DEBUG) { System.out.println(s); } } } and the like. But that doesn't bliss me out, because of course it works but there could be too many classes in which to set DEBUG to true, if you are not staring at just a couple of them. Conversely, I (like - I think - many others) wouldn't love to put the whole application in debug mode, as the amount of text being output could be overwhelming. So, is there a correct way to architecturally handle such situation or the most correct way is to use the DEBUG class member?

    Read the article

  • Why does Java allow to implement different interfaces, each containing a method with the same signature?

    - by Software Engeneering Learner
    I've recently found that I can have two interfaces containing method with the same signature as a method in the other interface. And then I can have an interface or class that implements both of that interfaces. So the descendant class/interface has implicitly implements two different methods as a one method. Why is this allowed in Java? I can see a numerous problems that arises from that. Even eclipse only can find out about implementations for only one interface method, but for the second one it doesn't show any implementations at all. Also I believe there would be problems with automatic refactoring, like when you would like to change the signature of the method in one of the interfaces and IDE won't be able to correctly change that signature in all implementations, as they implement two different interfaces and how will IDE know what interface method it implementation descends. Why don't just make a compiler error like 'interfaces method names clashes' or something like that?

    Read the article

  • How to remove java.sql.BatchUpdateException in Grails? [closed]

    - by aman.nepid
    I have a domain like this: class BusinessOrganization { static hasMany = [organizationBusinessTypes:OrganizationBusinessType] String name String icon static constraints = { name(blank:false,unique:true) icon(unique:true) } String toString() { return "${name}" } } When I save some data for first time it works fine. But when by the next time it shows this error : Error 500: Internal Server Error URI /nLocatePortal/businessOrganization/save Class java.sql.BatchUpdateException Message Batch entry 0 insert into business_organization (version, icon, name, id) values ('0', '', 'dddd', '2') was aborted. Call getNextException to see the cause. **Around line 24 of grails-app/controllers/com/nlocate/portal/BusinessOrganizationController.groovy** 21: 22: def save() { 23: def businessOrganizationInstance = new BusinessOrganization(params) 24: if (!businessOrganizationInstance.save(flush: true)) { 25: render(view: "create", model: [businessOrganizationInstance: businessOrganizationInstance]) 26: return 27: } Please someone help me why this is happening. I am new to Grails. I have not modified the controllers but still I get this error.

    Read the article

  • Best resources to learn Game Development from a Java background?

    - by Julio
    Hi guys, I'm an enterprise Java programmer, however something I've been interested in and what got me into the whole programming thing was the idea of being able to create a game. Just wondering if anybody could offer any advice, or book recommendations. The side I am most interested in is game engine design and implementation. People may say "ahh but plenty exist why write your own" - its purely for learning purposes, seeing how things work and so on. So far I've taken a look at LWJGL, but achieved nothing too serious. Thanks.

    Read the article

  • Why should most logic be in the monitor objects and not in the thread objects when writing concurrent software in Java?

    - by refuser
    When I took the Realtime and Concurrent programming course our lecturer told us that when writing concurrent programs in Java and using monitors, most of the logic should be in the monitor and as little as possible in the threads that access it. I never really understood why and I really would like to. Let me clarify. In this particular case we had several classes. Lift extends Thread Person extends Thread LiftView Monitor, all methods synchronized. This is nothing we came up with, our task was to implement a lift simulation with persons waiting on different floors, and theses were the class skeletons that were given. Then our lecturer said to implement most of the logic in the monitor (he was talking about class Monitor as THE monitor) and as little as possible in the threads. Why would he make a statement like that?

    Read the article

< Previous Page | 110 111 112 113 114 115 116 117 118 119 120 121  | Next Page >