GetMethodID找不到id-android JNI

Question

package ch.geniali.Test.service;
public class Service extends Service {
    private void sendMessage(String message) {
        Intent intent = new Intent();
        intent.setAction(Const.ACTION_INFO);
        intent.putExtra(Const.INTENT_MESSAGE, message);
        sendBroadcast(intent);
    }
}

#include <jni.h>
#include <string.h>
#include <android/log.h>
#define DEBUG_TAG "C_libG"

JavaVM* gJavaVM = NULL;
static JNIEnv *pEnv;
const char* kJavaClassPath = "ch/geniali/Test/service/Service";

JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM* pVm, void* reserved){
    __android_log_print(ANDROID_LOG_DEBUG, DEBUG_TAG, "Call JNI_OnLoad");

    gJavaVM = pVm;

    if((*pVm)->GetEnv(pVm, (void **)&pEnv, JNI_VERSION_1_6)){
        __android_log_print(ANDROID_LOG_DEBUG, DEBUG_TAG,
                    "Failed to get the environment");
        return -1;
    }

    jclass gClass = (*pEnv)->FindClass(pEnv, kJavaClassPath);
    if (!gClass)
     {
        __android_log_print(ANDROID_LOG_DEBUG, DEBUG_TAG,"failed to get %s class reference", kJavaClassPath);
      return -1;
     }

    jmethodID mid = (*pEnv)->GetMethodID(pEnv, gClass, "sendMessage", "(Ljava/lang/String;)V");
    if (mid == 0){
        __android_log_print(ANDROID_LOG_DEBUG, DEBUG_TAG,"Method ID not found");
        return -1;
    }

    (*pEnv)->CallVoidMethod(pEnv, gClass, mid, "yay!!!");

    return JNI_VERSION_1_6;
}

03-21 20:46:07.059 161 82-16182/ch.geniali.test：任务w/dalvikvm？JNI警告：不能在LJava/Lang/Class的实例上调用lch/geniali/test/service/service；.sendmessage；（CallVoidMethod）

03-21 20:46:07.059 161 82-16182/ch.geniali.test：任务w/dalvikvm？在ljava/lang/runtime；.nativeLoad中：（ljava/lang/string；ljava/lang/classloader；ljava/lang/string；）ljava/lang/string；（CallVoidMethod）

03-21 20:46:07.059 161 82-16182/CH.Geniali.Test：任务I/Dalvikvm？“main”prio=5 tid=1可运行

Answer 1

方法ID被正确找到，否则您将看到

__android_log_print(ANDROID_LOG_DEBUG, DEBUG_TAG,"Method ID not found");

你的Android日志中的消息。

您的错误是尝试在java.lang.class对象上调用sendMessage()方法，方法是执行以下操作

(*pEnv)->CallVoidMethod(pEnv, **gClass**, mid, "yay!!!");