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6 Replies Latest reply: Feb 1, 2012 4:44 AM by balind RSS

Ignored exception: java.lang.Exception in java.console.log

balind Newbie
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Hi,

we are using javascript - java (applet) communication in our software's start sequence.

We are testing if the applet is loaded and if a special applet method is avaiable in the javascript code
(typeof(myApplet.myMethod) != 'undefined').
After this test we are calling applet's method.

This works fine in most of all cases.

One of our customers seems to have problems in accessing this applet.
There are exceptions in the java console log:
<message>Ignored exception: java.lang.Exception: myMethod :Method not found</message>
<message>Ignored exception: java.lang.Exception: java.lang.Exception: myMethod :Method not found</message>

We are trying to access myMethod severall times but there always occurs this exception.
Nevertheless, the method "myMethod" seems to be executed (there are logging entries from this method later in log)

The jar-file that contains the applet class and myMethod is completely loaded. The jar file with the applet class is signed, we are using https.

Our customer has tested with IE8 and Firefox 8, JRE 1.60.21 and 1.60.29. Browser and java cache have always been cleared.

I have never seen such an exception in the java console log.

Are there any ideas, known problems?

Thanks in advance.
  • 1. Re: Ignored exception: java.lang.Exception in java.console.log
    801313 Explorer
    Currently Being Moderated
    This is very strange. But if, as you say, the method actually is found and is running, then I would chalk this up to a minor bug in the java plugin that the client your client is using, and leave it at that
  • 2. Re: Ignored exception: java.lang.Exception in java.console.log
    balind Newbie
    Currently Being Moderated
    Our problem is that we need this applet method in a login procedure and the javascript code has to check if any exceptions are thrown. In case of exceptions the applet method is called again (several times). On some systems of our customer we are always getting these exceptions, therefore our login procedure fails and the customer is not able to complete his login sucessful.

    The same code is working on many other clients without problems.
  • 3. Re: Ignored exception: java.lang.Exception in java.console.log
    801313 Explorer
    Currently Being Moderated
    The same code is working on many other clients without problems.
    Yes you said this in your first post.

    I don't have an ideas for workarounds given your requirement that the exception not show up in the console, but I would just comment that scanning the console for the traces of exceptions and taking actions based on that is not generally a good strategy. Java has all the facilities (ie try/catch) you need to handle these problems directly and you avoid problems like this
  • 4. Re: Ignored exception: java.lang.Exception in java.console.log
    balind Newbie
    Currently Being Moderated
    I agree that scanning java console and taking actions based on this is not a good idea :-)

    But we aren't doing that. Normally I don't read the java console log, but I was searching for a reason for not working clients on customer side.

    I hoped to get an information in which situation such an error could occur (maybe incomplete appet loading, timing problems).

    The myApplet.myMethod is surrounded with a javascript try/catch block. We are getting an exception, therefore there is a second attempt to call myApplet.myMethod.

    At the moment we don't know the exact exception text. Because we cannot reproduce the error on our systems we have send a modified javascript file that protocols the exception to our customer.

    Depending on the message text it could be a solution to ignore this very special exception. But this is not a very smart solution.
  • 5. Re: Ignored exception: java.lang.Exception in java.console.log
    817264 Journeyer
    Currently Being Moderated
    - Enable full tracing details. See here:
    http://docs.oracle.com/javase/7/docs/webnotes/tsg/TSG-Desktop/html/plugin.html#gcexdf

    - Does your customer run plugin1 or plugin2?

    - Can he see same issue with JRE7?
    And with latest beta drop - http://jdk7.java.net/download.html ?

    - Is it first call to the applet that fails?
    Can you add test callbacks from applet to js code to see if live connect is working?
    Do they work before fist attempt to call applet?
  • 6. Re: Ignored exception: java.lang.Exception in java.console.log
    balind Newbie
    Currently Being Moderated
    Thanks for the excellent link.

    I will ask the customer to turn on full trace.

    I think the customer is running plugin2. I asked him to make the oracle installation test. He reported that an older java version is found: Java SE Update 21 on Firefox and that the test throws a java exception with Internet Explorer: java.lang.ClassNotFoundException: testJava2_1.TestVMApplet.class.
    I'm a little bit irritated about the 'SE' in the java version.

    It is the first call to the applet that fails.

    Maybe there are proxy problems on some browsers.

Legend

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