Eclipse 错误“java.lang.unsatisfiedlinkerror 未找到本机方法”

Question

我正在通过 Eclipse Luna + APK19 + ndk_r10b 开发 Android 项目。 我尝试通过一些在线教程了解 NDK 开发流程。 http://www.decom.ufop.br/imobilis/?p=1832

我可以在Eclipse中编译没有错误，但是当我运行到虚拟设备时，它会弹出错误“java.lang.unsatisfiedlinkerror Native method not found”，然后虚拟设备显示“Unexpected Stop”。我尝试导出为.apk，它在硬件上也失败了。我尝试更改不同的教程，但出现了同样的问题。

能否帮助我了解如何调试？ 我在这里停留了一个多星期，非常感谢您的帮助。 提前致谢。

09-30 03:07:15.668: I/Process(1723): Sending signal. PID: 1723 SIG: 9
09-30 03:29:02.248: D/dalvikvm(1770): Trying to load lib /data/app-lib/com.test.ndkexample-
2/libNativeFunctionality.so 0xb4d45338
09-30 03:29:02.248: D/dalvikvm(1770): Added shared lib /data/app-lib/com.test.ndkexample 2/libNativeFunctionality.so 0xb4d45338
09-30 03:29:02.248: D/dalvikvm(1770): No JNI_OnLoad found in /data/app-lib/com.test.ndkexample ibNativeFunctionality.so 0xb4d45338, skipping init
09-30 03:29:02.568: W/dalvikvm(1770): No implementation found for native Lcom/test/ndkexample/MainActivity;.HelloWorldNDK:()V
09-30 03:29:02.568: D/AndroidRuntime(1770): Shutting down VM
09-30 03:29:02.568: W/dalvikvm(1770): threadid=1: thread exiting with uncaught exception (group=0xb4a94ba8)
09-30 03:29:02.578: E/AndroidRuntime(1770): FATAL EXCEPTION: main
09-30 03:29:02.578: E/AndroidRuntime(1770): Process: com.test.ndkexample, PID: 1770
09-30 03:29:02.578: E/AndroidRuntime(1770): java.lang.UnsatisfiedLinkError: Native method not found: com.test.ndkexample.MainActivity.HelloWorldNDK:()V
09-30 03:29:02.578: E/AndroidRuntime(1770):     at com.test.ndkexample.MainActivity.onStart(MainActivity.java:34)
09-30 03:29:02.578: E/AndroidRuntime(1770):     at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1171)
09-30 03:29:02.578: E/AndroidRuntime(1770):     at android.app.Activity.performStart(Activity.java:5241)
09-30 03:29:02.578: E/AndroidRuntime(1770):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2168)
09-30 03:29:02.578: E/AndroidRuntime(1770):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
09-30 03:29:02.578: E/AndroidRuntime(1770):     at android.app.ActivityThread.access$800(ActivityThread.java:135)
09-30 03:29:02.578: E/AndroidRuntime(1770):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
09-30 03:29:02.578: E/AndroidRuntime(1770):     at android.os.Handler.dispatchMessage(Handler.java:102)
09-30 03:29:02.578: E/AndroidRuntime(1770):     at android.os.Looper.loop(Looper.java:136)
09-30 03:29:02.578: E/AndroidRuntime(1770):     at android.app.ActivityThread.main(ActivityThread.java:5017)
09-30 03:29:02.578: E/AndroidRuntime(1770):     at java.lang.reflect.Method.invokeNative(Native Method)
09-30 03:29:02.578: E/AndroidRuntime(1770):     at java.lang.reflect.Method.invoke(Method.java:515)
09-30 03:29:02.578: E/AndroidRuntime(1770):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
09-30 03:29:02.578: E/AndroidRuntime(1770):     at     com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
09-30 03:29:02.578: E/AndroidRuntime(1770):     at dalvik.system.NativeStart.main(Native Method)

MainActivity.java

package com.test.ndkexample;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;

public class MainActivity extends ActionBarActivity {

    static {
        System.loadLibrary("NativeFunctionality");
        }

    TextView ndkTextView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {    
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
    }

    @Override
    protected void onStart() {
    super.onStart();
    HelloWorldNDK();
    ndkTextView = (TextView)findViewById(R.id.ndkText);
    String ndkString = GetAnswer();
    ndkTextView.setText(ndkString);
    }


    public native void HelloWorldNDK();
    public native String GetAnswer();
    }  

NativeFunctionality.cpp

#include <jni.h>
#include "NativeFunctionality.h"
#include <android/log.h>
#include <pthread.h>
#include <unistd.h>
#define LOG_TAG "NDKTest"

JNIEXPORT void JNICALL Java_com_test_NDKExample_MainActivity_HelloWorldNDK
(JNIEnv *env, jobject obj)
{
__android_log_print(ANDROID_LOG_INFO,LOG_TAG,"Native function called!");

return;

}

JNIEXPORT jstring JNICALL Java_com_test_NDKExample_MainActivity_GetAnswer
(JNIEnv *env, jobject obj)

{

    return (env->NewStringUTF("String returned from native environment!"));

}

NativeFunctionality.h

/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class com_test_ndkexample_MainActivity */

#ifndef _Included_com_test_ndkexample_MainActivity
#define _Included_com_test_ndkexample_MainActivity
 #ifdef __cplusplus

extern "C" {

#endif
/*
 * Class:     com_test_ndkexample_MainActivity
 * Method:    HelloWorldNDK
 * Signature: ()V
     */
JNIEXPORT void JNICALL Java_com_test_ndkexample_MainActivity_HelloWorldNDK
  (JNIEnv *, jobject);

 /*
 * Class:     com_test_ndkexample_MainActivity
 * Method:    GetAnswer
 * Signature: ()Ljava/lang/String;
 */
JNIEXPORT jstring JNICALL Java_com_test_ndkexample_MainActivity_GetAnswer
  (JNIEnv *, jobject);

#ifdef __cplusplus

}
#endif
#endif

Android.mk

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog
LOCAL_MODULE    := NativeFunctionality
LOCAL_SRC_FILES := NativeFunctionality.cpp

include $(BUILD_SHARED_LIBRARY)

Answer 1

JNIEXPORT void JNICALL Java_com_test_NDKExample_MainActivity_HelloWorldNDK(JNIEnv *env, jobject obj)

不正确。您的函数名称必须与您的本机方法声明完全匹配，包括大写（或不包括）包名。

package com.test.ndkexample;
public class MainActivity extends ActionBarActivity {
    public native void HelloWorldNDK();
}

需要

JNIEXPORT void JNICALL Java_com_test_ndkexample_MainActivity_HelloWorldNDK(JNIEnv *env, jobject obj)