Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-4879884

NullPointerException thrown before init and getDocumentBase() returns null

XMLWordPrintable

    • Icon: Bug Bug
    • Resolution: Duplicate
    • Icon: P4 P4
    • None
    • 1.4.2
    • deploy
    • x86
    • windows_xp



      Name: gm110360 Date: 06/17/2003


      FULL PRODUCT VERSION :
      java version "1.4.1_02"
      Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1_02-b06)
      Java HotSpot(TM) Client VM (build 1.4.1_02-b06, mixed mode)

      FULL OS VERSION :
      Microsoft Windows XP [Version 5.1.2600]

      EXTRA RELEVANT SYSTEM CONFIGURATION :
      ATI graphics card

      A DESCRIPTION OF THE PROBLEM :
      When an applet tag is written to an HTML document, the applet is loaded but a NullPointerException is thrown before init and getDocumentBase() returns null. If the applet tag appears in the HTML when it is loaded or on 1.3.x versions of the plug-in, everything works fine.

      STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
      - Compile AppletTest.java (source below) in the same directory as applet-inline.html and applet-written.html
      - Configure IE to use java plug-in 1.4.1_02 (or any previous 1.4.x)
      - Open applet-inline.html (source below) in IE.
      - Open the java console. It will show (as expected) something like:
      here in init
      ac = sun.plugin.viewer.context.IExplorerAppletContext@d6a05e
      db = file:/C:/at/applet-inline.html
      - Open applet-written.html (source below) in IE.
      - Open the java console. It will show something like:
      java.lang.NullPointerException
      at sun.plugin.viewer.context.IExplorerAppletContext.getJSObject(Unknown Source)
      at sun.plugin.AppletViewer.getDocumentBase(Unknown Source)
      at sun.plugin.AppletViewer.getCodeBase(Unknown Source)
      at sun.plugin.AppletViewer.appletInit(Unknown Source)
      at sun.plugin.viewer.LifeCycleManager.initAppletPanel(Unknown Source)
      at sun.plugin.viewer.IExplorerPluginObject$Initer.run(Unknown Source)
      here in init
      ac = sun.plugin.viewer.context.IExplorerAppletContext@1b3f8f6
      db = null


      EXPECTED VERSUS ACTUAL BEHAVIOR :
      The console should contain something like:

      here in init
      ac = sun.plugin.viewer.context.IExplorerAppletContext@d6a05e
      db = file:/C:/at/applet-inline.html

      as it does for applet-inline.html and for both .html files using a 1.3.x plug-in.
      With applet-written.html and the 1.4.x plug-in, the console contains:

      java.lang.NullPointerException
      at sun.plugin.viewer.context.IExplorerAppletContext.getJSObject(Unknown Source)
      at sun.plugin.AppletViewer.getDocumentBase(Unknown Source)
      at sun.plugin.AppletViewer.getCodeBase(Unknown Source)
      at sun.plugin.AppletViewer.appletInit(Unknown Source)
      at sun.plugin.viewer.LifeCycleManager.initAppletPanel(Unknown Source)
      at sun.plugin.viewer.IExplorerPluginObject$Initer.run(Unknown Source)
      here in init
      ac = sun.plugin.viewer.context.IExplorerAppletContext@1b3f8f6
      db = null


      ERROR MESSAGES/STACK TRACES THAT OCCUR :
      See results above.

      REPRODUCIBILITY :
      This bug can be reproduced always.

      ---------- BEGIN SOURCE ----------
      Here is AppletTest.java:
      ----------------------------------------------------------------------
      import java.net.URL;
      import java.applet.Applet;

      public class AppletTest extends Applet
      {
          public void init()
          {
      System.err.println("here in init");

      System.err.println("ac = " + getAppletContext());

      URL db = getDocumentBase();

      System.err.println("db = " + db);
          }
      }
      ----------------------------------------------------------------------
      Here is applet-inline.html:
      ----------------------------------------------------------------------
      <html>
      <head>
      <title>Applet Test</title>
      </head>
      <body>
      <applet name="AppletTest" code="AppletTest.class" width=100 height=40
       mayscript></applet>
      </body>
      </html>
      ----------------------------------------------------------------------
      Here is applet-written.html:
      ----------------------------------------------------------------------
      <html>
      <head>
      <title>Applet Test</title>
      <script type='text/javascript'>
      <!--
      function go()
      {
          var s = '<applet name="AppletTest" ' +
      'code="AppletTest.class" ' +
      'width=100 ' +
      'height=40 ' +
      'mayscript>' +
      '</applet>';

          if (document.all)
      document.all.appletHolder.innerHTML = s;
          else if (document.getElementById)
      document.getElementById('appletHolder').innerHTML = s;
          else
      alert('This example doesn\'t work on your browser');
      }
      //-->
      </script>
      </head>
      <body onload="go()">
      <div id=appletHolder style="position: absolute;"></div>
      </body>
      </html>

      ---------- END SOURCE ----------
      (Review ID: 184110)
      ======================================================================

            mafishersunw Margarita Fisher (Inactive)
            gmanwanisunw Girish Manwani (Inactive)
            Votes:
            0 Vote for this issue
            Watchers:
            0 Start watching this issue

              Created:
              Updated:
              Resolved:
              Imported:
              Indexed: