Name: rmT116609 Date: 04/22/2004


FULL PRODUCT VERSION :
java version "1.4.2_04"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_04-b05)
Java HotSpot(TM) Client VM (build 1.4.2_04-b05, mixed mode)

java version "1.5.0-beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-beta-b32c)
Java HotSpot(TM) Client VM (build 1.5.0-beta-b32c, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
When the property swing.defaultlaf is set to a class that does not exist, Java opens a dialog box saying "Java Virtual Machine Launcher: fatal exception occured. Program will exit" and exits. I think this should be considered a bug since a wrong setting at the command line or in a file should not crash Java.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Create a file called swing.properties and put it in <java_home>\lib. The file contains a line

swing.defaultlaf=javax.swing.plaf.metal.MetalLookAndFeelx

Please note the additional x. Clearly such a class is not present and therefor the above message appears. If I remove the trailing x everything works fine, of course

or

Open cmd.exe.

Run SwingSet2 as follows:

C:\tmpjava>java -Dswing.defaultlaf=javax.swing.plaf.metal.MetalLookAndFeel -jar
\j2sdk1.4.2_04\demo\jfc\SwingSet2\SwingSet2.jar

-> works great!

Now do the same once more, but notice the incorrect look and feel class:

C:\tmpjava>java -Dswing.defaultlaf=javax.swing.plaf.metal.MetalLookAndFeelX -jar
\j2sdk1.4.2_04\demo\jfc\SwingSet2\SwingSet2.jar
Exception in thread "main" java.lang.Error: can't load javax.swing.plaf.metal.Me
talLookAndFeelX
        at javax.swing.UIManager.initializeDefaultLAF(UIManager.java:1091)
        at javax.swing.UIManager.initialize(UIManager.java:1181)
        at javax.swing.UIManager.maybeInitialize(UIManager.java:1164)
        at javax.swing.UIManager.getUI(UIManager.java:775)
        at javax.swing.JPanel.updateUI(JPanel.java:104)
        at javax.swing.JPanel.<init>(JPanel.java:64)
        at javax.swing.JPanel.<init>(JPanel.java:87)
        at javax.swing.JPanel.<init>(JPanel.java:95)
        at SwingSet2.<init>(SwingSet2.java:191)
        at SwingSet2.main(SwingSet2.java:243)

The same error occurs when you create the file swing.properties and put it to <java_home>\lib. Insert a line swing-defaultlaf=...

SwingSet will work perfectly if the fully qualified classname after swing.defaultlauf= exists, otherwise Java crashes.

The same behaviour can be seen under Tiger Beta1

As I have already pointed out, in my humble opinion Java should not crash if a specified look and feel does not exist but use the default one that would be used if swing.defaultlaf was not specified by the user at all.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
If the specified class cannot be instantiated, Java should behave as if the property had not been set and use another default look and feel
ACTUAL -
Java opens a dialog box saying "Java Virtual Machine Launcher: fatal exception occured. Program will exit" and exits

ERROR MESSAGES/STACK TRACES THAT OCCUR :
Java opens a dialog box saying "Java Virtual Machine Launcher: fatal exception occured. Program will exit" and exits

REPRODUCIBILITY :
This bug can be reproduced always.
(Incident Review ID: 240832)
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