Java 6和SwingUtilities2

Question

There is component within the application that uses com.sun.java.swing.SwingUtilities2 Now I understand that this class shouldn't be used, but it's a component within the system that uses it.

Therefore since it's no longer available in Java 6 I get a NoClassDefFoundError. How can I get around this issue without having to upgrade the component as I don't yet know if that's an option.

Answer 1

If you have absolutely no other choice, then you should figure out exactly what it was that the class is using from SwingUtilities2, and then make proxies for that functionality in your own SwingUtilities2. You can then stick it in your own com.sun.java.swing package, which will overlap with the original one, and if the same class loader that loads your component is also aware of SwingUtilities2, then the one will see the other and your application will work.

Depending on what the component is, and what it used out of SwingUtilities2, this could be significantly harder than upgrading it or even rewriting it.

Answer 2

Da-dum! This is precisely why you should pay attention to those pesky warnings admonishing you not to rely upon internals of the JVM!

Answer 3

Just a though, I don't know if this would work.

Try pulling out the SwingUtilities2 class and put it in a patch jar, include this jar in your classpath. Hopefully this works until you can change the source.

Answer 4

The only correct way (out of hacking) is to ask vendor to fix and rebuild this component to Java 6. The possible working way is copy sun.swing.SU2 to com.sun...SU2 and package it into separate jar (eg java6fix.jar) and try to run your application. It will be fine if you add this patch jar into jvm bootclasspath. The best patch should be to create own com.sun..SU2 and delegate all calls to sun.swing.SU2. And take a look for different version of component which support Java6 maybe also from different vendor. Also if the problem is only in the mentioned line ((Boolean)c.getClientProperty(AA_TEXT_PROPERTY_KEY)); then you may put your own client property for this component to prevent NPE. When you take this path you can just simply create your own com.sun...SU2.AA_TEXT_PROPERTY_KEY and call c.setClientProperty(AA_TEXT_PROPERTY_KEY, true) on this component. Also try to disable anti aliasing check on component if possible.