android java 调用 .so 动态库实例
MainActivity.javapackage com.example.com.test.jni;
import android.view.View;
import android.view.View.OnClickListener;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
private EditText mSetValue = null;
private TextView mGetValue = null;
private Button mButton = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSetValue = (EditText) findViewById(R.id.setValue);
mGetValue = (TextView) findViewById(R.id.getValue);
mButton = (Button) findViewById(R.id.mButton);
mButton.setOnClickListener(new ButtonClick());
}
class ButtonClick implements OnClickListener{
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
int val = Integer.parseInt(mSetValue.getText().toString());
setValue(val);
int temp = getValue();
mGetValue.setText(""+temp);
}
}
static
{
System.loadLibrary("testJNI");
}
public native static int getValue();
public native static void setValue(int i);
}
activity_main.xml
使用 javah命令生成 JNI 的接口文件 注意：执行命令在原代码的目录下面，不要在 .class文件的目录线面。eg:Java项目目录是 E：/TestJNI , windows 下 cmd 进入到 E：/TestJNI/src 执行 ：javah com.example.com.test.jni.MainActivity执行前如果运行的是 Android 代码 需要在环境变量 classpath中添加 sdk的位置
生成的com_example_com_test_jni_MainActivity.h文件
/* DO NOT EDIT THIS FILE - it is machine generated */
#include
/* Header for class com_example_com_test_jni_MainActivity */
#ifndef _Included_com_example_com_test_jni_MainActivity
#define _Included_com_example_com_test_jni_MainActivity
#ifdef __cplusplus
extern "C" {
#endif
#undef com_example_com_test_jni_MainActivity_BIND_ABOVE_CLIENT
#define com_example_com_test_jni_MainActivity_BIND_ABOVE_CLIENT 8L
#undef com_example_com_test_jni_MainActivity_BIND_ADJUST_WITH_ACTIVITY
#define com_example_com_test_jni_MainActivity_BIND_ADJUST_WITH_ACTIVITY 128L
#undef com_example_com_test_jni_MainActivity_BIND_ALLOW_OOM_MANAGEMENT
#define com_example_com_test_jni_MainActivity_BIND_ALLOW_OOM_MANAGEMENT 16L
#undef com_example_com_test_jni_MainActivity_BIND_AUTO_CREATE
#define com_example_com_test_jni_MainActivity_BIND_AUTO_CREATE 1L
#undef com_example_com_test_jni_MainActivity_BIND_DEBUG_UNBIND
#define com_example_com_test_jni_MainActivity_BIND_DEBUG_UNBIND 2L
#undef com_example_com_test_jni_MainActivity_BIND_IMPORTANT
#define com_example_com_test_jni_MainActivity_BIND_IMPORTANT 64L
#undef com_example_com_test_jni_MainActivity_BIND_NOT_FOREGROUND
#define com_example_com_test_jni_MainActivity_BIND_NOT_FOREGROUND 4L
#undef com_example_com_test_jni_MainActivity_BIND_WAIVE_PRIORITY
#define com_example_com_test_jni_MainActivity_BIND_WAIVE_PRIORITY 32L
#undef com_example_com_test_jni_MainActivity_CONTEXT_IGNORE_SECURITY
#define com_example_com_test_jni_MainActivity_CONTEXT_IGNORE_SECURITY 2L
#undef com_example_com_test_jni_MainActivity_CONTEXT_INCLUDE_CODE
#define com_example_com_test_jni_MainActivity_CONTEXT_INCLUDE_CODE 1L
#undef com_example_com_test_jni_MainActivity_CONTEXT_RESTRICTED
#define com_example_com_test_jni_MainActivity_CONTEXT_RESTRICTED 4L
#undef com_example_com_test_jni_MainActivity_MODE_APPEND
#define com_example_com_test_jni_MainActivity_MODE_APPEND 32768L
#undef com_example_com_test_jni_MainActivity_MODE_ENABLE_WRITE_AHEAD_LOGGING
#define com_example_com_test_jni_MainActivity_MODE_ENABLE_WRITE_AHEAD_LOGGING 8L
#undef com_example_com_test_jni_MainActivity_MODE_MULTI_PROCESS
#define com_example_com_test_jni_MainActivity_MODE_MULTI_PROCESS 4L
#undef com_example_com_test_jni_MainActivity_MODE_PRIVATE
#define com_example_com_test_jni_MainActivity_MODE_PRIVATE 0L
#undef com_example_com_test_jni_MainActivity_MODE_WORLD_READABLE
#define com_example_com_test_jni_MainActivity_MODE_WORLD_READABLE 1L
#undef com_example_com_test_jni_MainActivity_MODE_WORLD_WRITEABLE
#define com_example_com_test_jni_MainActivity_MODE_WORLD_WRITEABLE 2L
#undef com_example_com_test_jni_MainActivity_DEFAULT_KEYS_DIALER
#define com_example_com_test_jni_MainActivity_DEFAULT_KEYS_DIALER 1L
#undef com_example_com_test_jni_MainActivity_DEFAULT_KEYS_DISABLE
#define com_example_com_test_jni_MainActivity_DEFAULT_KEYS_DISABLE 0L
#undef com_example_com_test_jni_MainActivity_DEFAULT_KEYS_SEARCH_GLOBAL
#define com_example_com_test_jni_MainActivity_DEFAULT_KEYS_SEARCH_GLOBAL 4L
#undef com_example_com_test_jni_MainActivity_DEFAULT_KEYS_SEARCH_LOCAL
#define com_example_com_test_jni_MainActivity_DEFAULT_KEYS_SEARCH_LOCAL 3L
#undef com_example_com_test_jni_MainActivity_DEFAULT_KEYS_SHORTCUT
#define com_example_com_test_jni_MainActivity_DEFAULT_KEYS_SHORTCUT 2L
#undef com_example_com_test_jni_MainActivity_RESULT_CANCELED
#define com_example_com_test_jni_MainActivity_RESULT_CANCELED 0L
#undef com_example_com_test_jni_MainActivity_RESULT_FIRST_USER
#define com_example_com_test_jni_MainActivity_RESULT_FIRST_USER 1L
#undef com_example_com_test_jni_MainActivity_RESULT_OK
#define com_example_com_test_jni_MainActivity_RESULT_OK -1L
/*
* Class: com_example_com_test_jni_MainActivity
* Method: getValue
* Signature: ()I
*/
JNIEXPORT jint JNICALL Java_com_example_com_test_jni_MainActivity_getValue
(JNIEnv *, jobject);
/*
* Class: com_example_com_test_jni_MainActivity
* Method: setValue
* Signature: (I)V
*/
JNIEXPORT void JNICALL Java_com_example_com_test_jni_MainActivity_setValue
(JNIEnv *, jobject, jint);
#ifdef __cplusplus
}
#endif
#endif
再实现对应的
com_example_com_test_jni_MainActivity.cpp文件
#include "com_example_com_test_jni_MainActivity.h"
int i = 0;
jint Java_com_example_com_test_jni_MainActivity_getValue(JNIEnv *env, jobject jc)
{
return i;
}
void Java_com_example_com_test_jni_MainActivity_setValue(JNIEnv *env, jobject jc, jint j)
{
i = j;
}
两个文件生成之后就可以编译了
gcc -fPIC -D_REENTRANT -I /usr/lib/jvm/java-1.7.0-openjdk-amd64/include/ -I /usr/lib/jvm/java-1.7.0-openjdk-amd64/include/linux/ -c com_example_com_test_jni_MainActivity.cpp 编译目标文件 com_example_com_test_jni_MainActivity.o
gcc -shared com_example_com_test_jni_MainActivity.o -o libtestJNI.so 生成动态库
这样生成的动态库 会有32 64 位不一致问题，具体怎么搞好没有研究
如果有Android 工程的话可以编写个 Android.mk直接编译即可Android.mk
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE_TAGS := optional
LOCAL_MODULE := libtestJNI
LOCAL_32_BIT_ONLY := true
LOCAL_LDFLAGS += -Wl,--no-warn-shared-textrel
LOCAL_LDFLAGS += -Wl,--no-fatal-warnings
LOCAL_SRC_FILES += com_example_com_test_jni_MainActivity.cpp \
include $(BUILD_SHARED_LIBRARY)
将生成的 .so文件放到app工程的 libs/armeabi 目录下面编译即可