/* gets target VM version from the given VMVersionMismatchException.
* Note that we need to reflectively call the method because of we may
* have got this from different classloader's namespace */
private static String getVMVersion(Throwable throwable)
throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
// assert isVMVersionMismatch(throwable), "not a VMVersionMismatch"
Class expClass = throwable.getClass();
Method targetVersionMethod = expClass.getMethod("getTargetVersion", new Class[0]);
return (String) targetVersionMethod.invoke(throwable);
}
/**
* If the causal chain has a sun.jvm.hotspot.runtime.VMVersionMismatchException, attempt to load
* VirtualMachineImpl class for target VM version.
*/
protected static Class handleVMVersionMismatch(InvocationTargetException ite) {
Throwable cause = ite.getCause();
if (DEBUG) {
System.out.println("checking for version mismatch...");
}
while (cause != null) {
try {
if (isVMVersionMismatch(cause)) {
if (DEBUG) {
System.out.println("Triggering cross VM version support...");
}
return loadVirtualMachineImplClass(getVMVersion(cause));
}
} catch (Exception exp) {
if (DEBUG) {
System.out.println("failed to load VirtualMachineImpl class");
exp.printStackTrace();
}
return null;
}
cause = cause.getCause();
}
return null;
}
/* Is the given throwable an instanceof VMVersionMismatchException?
* Note that we can't do instanceof check because the exception
* class might have been loaded by a different class loader.
*/
private static boolean isVMVersionMismatch(Throwable throwable) {
String className = throwable.getClass().getName();
return className.equals("sun.jvm.hotspot.runtime.VMVersionMismatchException");
}