Java高级应用之JNI

参考link
http://www.cnblogs.com/liuling/p/2013-12-20.html
http://blog.csdn.net/cl05300629/article/details/39050703

1 创建Java包含native方法的类，如下：

public class TestNative
{
	public native void sayHello();
}

2 通过JDK工具javah生成C/C++头文件，如下：

C:\Users\jacky_dai\Desktop\java>javah TestNative

3 生成如下的C++头文件，TestNative.h

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

#ifndef _Included_TestNative
#define _Included_TestNative
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     TestNative
 * Method:    sayHello
 * Signature: ()V
 */
JNIEXPORT void JNICALL Java_TestNative_sayHello
  (JNIEnv *, jobject);

#ifdef __cplusplus
}
#endif
#endif

4 创建C++ win32 DLL Project,并且包含java的include files并添加测试代码

#include <iostream>
#include "TestNative.h"
using namespace std;

JNIEXPORT void JNICALL Java_TestNative_sayHello(JNIEnv *, jobject);
{
    cout<<"hello world!"<<endl;
}

5 添加Java测试代码

public class TestNative
{
    public native void sayHello();
    
    /**
     * @param args
     */
    public static void main(String[] args) {
        System.loadLibrary("NativeCode");
        TestNative tNative = new TestNative();
        tNative.sayHello();    
    }
}

6 编译运行demo，可以看见输出的“Hello World!”

javah TestNative.java
java TestNative