What could cause SIGSEGV when calling NewObjectArray for JNI in Android?

Question

I just started working with the Android NDK but I keep getting SIGSEGV when I have this call in my C code:

jobjectArray someStringArray;
someStringArray = (*env)->NewObjectArray(env, 10, 
(*env)->FindClass(env,"java/lang/String"),(*env)->NewStringUTF(env, ""));

Base on all the example I can find, the above code is correct but I keep getting SIGSERGV and everything is ok if the NewObjectArray line is commented out. Any idea what could cause such a problem?

Answer 1

that looks right, so i'm guessing you've done something else wrong. i assume you're running with checkjni on? you might want to break that up into multiple lines: do the FindClass and check the return value, do the NewStringUTF and check the return value, and then call NewObjectArray.

btw, you might want to pass NULL as the final argument; this pattern of using the empty string as the default value for each element of the array is commonly used (i think it's copy & pasted from some Sun documentation and has spread from there) but it's rarely useful, and it's slightly wasteful. (and it doesn't match the behavior of "new String[10]" in Java.)