JNI methods modifying pointers

Question

Hello,

Having a peculiar problem. When I call the following JNI method.

jobjectArray array = env->NewObjectArray(list->size, jclass, 0);

Now, list->size is set to 54. But as soon as the code above is run the same pointer returns, 2405015736 whats going on? As affects the values held in the rest of the struct also. Setting a static value i.e.

jobjectArray array = env->NewObjectArray(54, jclass, 0)

Also has no effect. Any ideas? I'm stumped.

(jclass is a loaded class object jclass = env->FindClass("name"); )

Thanks

Answer 1

Your problem is that size may not be of 'jsize' type so conversion has to take place. Now, this would be all well and good, but JNI is an absolute pain with this stuff. I think what is happening is that your stack is getting corrupted from a number which is interpreted as being too big. Or something like that. Just do the size conversion like so:

jint msize = list->size;
jobjectArray array = env->NewObjectArray(msize, jclass, 0);

This should do the trick.