JNI - Exception Handling

来源：互联网发布：centos yum nmap 编辑：程序博客网时间：2024/05/29 19:18

.java file:

class CatchThrow{private native void doit()throws IllegalArgumentException;private void callback() throws NullPointerException{throw new NullPointerException("CathThrow.callback");}public static void main(String args[]){CatchThrow c = new CatchThrow();try {c.doit();} catch (Exception e){System.out.println("In Java:\n\t" + e);}}static {System.loadLibrary("CatchThrow");}}

.c file:

#include <jni.h>#include <stdio.h>#include "CatchThrow.h"JNIEXPORT void JNICALL <span style="color:#000099;">Java_CatchThrow_doit //do it.</span>  (JNIEnv *env, jobject obj){jthrowable exc;jclass cls = (*env)->GetObjectClass(env,obj);jmethodID mid = (*env)->GetMethodID(env, cls, "callback", "()V");if (mid == NULL) return;<span style="color:#000099;">(*env)->CallVoidMethod(env, obj, mid);//Invoke callback</span>exc = (*env)->ExceptionOccurred(env);if (exc){jclass newExcCls;<span style="color:#009900;">(*env)->ExceptionDescribe(env);//This stmt describes the stack trace.</span>(*env)->ExceptionClear(env);newExcCls = (*env)->FindClass(env, "java/lang/IllegalArgumentException");if (newExcCls == NULL){return;}(*env)->ThrowNew(env, newExcCls, "thrown from C code");}}

Result:

Exception in thread "main" java.lang.NullPointerException: CathThrow.callbackat CatchThrow.callback(CatchThrow.java:5)at CatchThrow.doit(Native Method)at CatchThrow.main(CatchThrow.java:10)In Java:java.lang.IllegalArgumentException: thrown from C code

In JNI, an exception does not immediately disrupt the native method execution. This is different from Java(JVM automatically transfer the control flow to the nearest try/catch).

JNI need to explicitly implement the control flow after an exception has occurred.

0 0