We recently finished migrating our product from Java5 to Java6. The software migration itself went quite smoothly with only a couple unanticipated problems.

However we do have a number of developers on MacBook Pro’s (myself included) that began having problems with other Java-based applications after making Java6 their default JVM.

One such problem was with the popular Spark IM client. After upgrading to Java6 we started getting the following exception:

macos:/Applications/Spark.app/Contents/MacOS ajordens$ ./JavaApplicationStub

NSRuntime.loadLibrary(/usr/lib/java/libObjCJava.dylib) error.

java.lang.UnsatisfiedLinkError: /usr/lib/java/libObjCJava.A.dylib:
at java.lang.ClassLoader$NativeLibrary.load(Native Method)
at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1822)
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1702)
at java.lang.Runtime.load0(Runtime.java:770)
at java.lang.System.load(System.java:1005)
at com.apple.cocoa.foundation.NSRuntime.loadLibrary(NSRuntime.java:127)

Revert back to Java6 and the problems disappeared.

Solution:

Reverting back to Java5 for a particular application was about the only suggestion I’ve seen that has actually worked.

Fortunately, you should be able to apply the change directly to the problem application’s Info.plist and not system-wide. Best of both worlds in a way.

Using the Spark example:

Edit /Applications/Spark.app/Contents/Info.plist and change the value associated with the JVMVersion key to be 1.5 instead of 1.5+.

Similar to a JNLP file, this will result in the runtime falling back to 1.5.0.