7u25 classloader revisited

Question

We have multiple WebStart based product streams requiring various JRE versions (e.g. 5u14,
6u43 and 7u21). If 7u25 or later is installed on the client the product fails to launch properly.
We have investigated the classloader change outlined in Oracle bug JDK-8017776.  The main
and associated bugs indicate this issue resolved in later JRE releases (e.g 7u40, 7u45 etc.)
Testing shows this to not be the case. If the classloader change is in place the product
launches and runs.
Internal testing of the classloader change has revealed an issue. If the Java Console is opened
at launch time and later closed the product starts to report ClassNotFoundExceptions.
Investigation shows that during launch the EDT classloader has been changed to:
com.sun.jnlp.JNLPClassLoader with a thread ID of say 18. If the console is closed and a
reproducible set of steps is applied ClassNotFoundExceptions are reported. Based on
the exception stacktraces I have added output statements to report the EDT classloader
and thread ID. The IDs are identical but the classloader is now reported as:
sun.misc.Launcher$AppClassLoader.
The same behavior is also observed if the console is left open and the "Clear" button is
selected. If the console is left open or not launched there is no issue. The problem is we
have no control over customer use of the Java Console.
There are reports of classloader issue resolution (no 8017776 change in place) if the
console window is left open. This is not the case in our testing nor is it an option if it
did resolve the issue.
Further testing shows that if the streams are compiled with 7u25 or later that the
8017776 change is not required. This is not an option at this time for numerous reasons.
Is the 8017776 change the only known solution for this issue?
Has there been any news from Oracle concerning an "official" fix?
I am interested in hearing from other developers that have addressed this issue.

Answer 1

Some additional information:
When clearing the Java Console the SwingConsoleWindow::clear() method is called. This method
,via an invokeLater method call, replaces the PlainDocument associated with the text area then
prints the version and help. These are printed via ConsoleHelper::displayVersion() and
ConsoleHelper::displayHelp().
Each of those methods makes use of SwingConsoleWindow::append() that itself uses invokeLater
method calls to queue an event for each line.
Many of the remaining actions that can be triggered in the console window do not use the append() method.
The ConsoleHelper methods are simply calls to the SwingConsoleWindow::append() method.
Methods from SwingConsoleWindow::
public void clear() {
    invokeLater(new Runnable() {
      public void run() {
        PlainDocument localPlainDocument = new PlainDocument();
        SwingConsoleWindow.this.textArea.setDocument(localPlainDocument);
        SwingConsoleWindow.this.textArea.revalidate();
        SwingConsoleWindow.this.setScrollPosition();
        ConsoleHelper.displayVersion(SwingConsoleWindow.this.controller, SwingConsoleWindow.this);
        SwingConsoleWindow.this.append("\n");
        ConsoleHelper.displayHelp(SwingConsoleWindow.this.controller, SwingConsoleWindow.this);
public void append(String paramString) {
    invokeLater(new Runnable() {
      private final String val$text;
      public void run() {
        int i = SwingConsoleWindow.this.textArea.getText().length() + this.val$text.length() - 1048575;
        try {
          if (i > 0) {
            SwingConsoleWindow.this.textArea.replaceRange("", 0, i);
          SwingConsoleWindow.this.textArea.append(this.val$text);
          SwingConsoleWindow.this.textArea.revalidate();
          SwingConsoleWindow.this.setScrollPosition();
        } catch (Exception localException)  {
          SwingConsoleWindow.this.clear();
          Trace.println(ResourceManager.getMessage("console.trace.error"));
private void invokeLater(Runnable paramRunnable)  {
    if (paramRunnable == null) {
      return;
    try  {
      DeploySysRun.execute(new DeploySysAction() {
        private final Runnable val$r;
        public Object execute()  {
          SwingUtilities.invokeLater(this.val$r);
          return null;
    } catch (Exception localException)  {
      Trace.ignoredException(localException);