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C调用java JNI

2015/4/10镜像同步7 回复

c中通过GetStaticMethodID()找java中的static方法,不知道为什么找不到.程序很简单,用ndk中的hello-jni改的. 以下为代码: hello-jni.c中: jstring Java_com_example_hellojni_HelloJni_stringFromJNI( JNIEnv* env, jobject thiz ) { #if defined(__arm__) #if defined(__ARM_ARCH_7A__) #if defined(__ARM_NEON__) #if defined(__ARM_PCS_VFP) #define ABI "armeabi-v7a/NEON (hard-float)" #else #define ABI "armeabi-v7a/NEON" #endif #else #if defined(__ARM_PCS_VFP) #define ABI "armeabi-v7a (hard-float)" #else #define ABI "armeabi-v7a" #endif #endif #else #define ABI "armeabi" #endif #elif defined(__i386__) #define ABI "x86" #elif defined(__x86_64__) #define ABI "x86_64" #elif defined(__mips64) /* mips64el-* toolchain defines __mips__ too */ #define ABI "mips64" #elif defined(__mips__) #define ABI "mips" #elif defined(__aarch64__) #define ABI "arm64-v8a" #else #define ABI "unknown" #endif jclass clazz = (*env)->FindClass(env, "com/example/hellojni/HelloJni"); if(clazz == NULL) { LOGD("cannot find class HelloJni"); } jmethodID java_method = (*env)->GetStaticMethodID(env, clazz, "test", "(V)V"); if(java_method == NULL) { LOGD("cannot find java_method"); }else { (*env)->CallStaticVoidMethod(env, clazz, java_method); } return (*env)->NewStringUTF(env, "Hello from JNI ! Compiled with ABI " ABI "."); } HelloJni.java中: public class HelloJni extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); /* Create a TextView and set its content. * the text is retrieved by calling a native * function. */ TextView tv = new TextView(this); tv.setText( stringFromJNI() ); setContentView(tv); } /* A native method that is implemented by the * 'hello-jni' native library, which is packaged * with this application. */ public native String stringFromJNI(); /* This is another native method declaration that is *not* * implemented by 'hello-jni'. This is simply to show that * you can declare as many native methods in your Java code * as you want, their implementation is searched in the * currently loaded native libraries only the first time * you call them. * * Trying to call this function will result in a * java.lang.UnsatisfiedLinkError exception ! */ public native String unimplementedStringFromJNI(); /* this is used to load the 'hello-jni' library on application * startup. The library has already been unpacked into * /data/data/com.example.hellojni/lib/libhello-jni.so at * installation time by the package manager. */ public static void test(){ Log.i("testTag", "wa ha ha"); } static { System.loadLibrary("hello-jni"); } } 在调用GetStaticMethodID()的时候程序还奔溃了.求问怎么改才对?

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