JNI java调用c函数 native 步骤 代码

步骤：

1、java中声明该函数为native

public class MyNative
{
public static native void greeting();
static
{
System.loadLibrary("MyNative");
}
public static void main(String[] args)
{
greeting();
}
}

2、编译

E:/native>javac MyNative.java

E:/native>javah MyNative

声称.h文件

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

#ifndef _Included_MyNative
#define _Included_MyNative
#ifdef __cplusplus
extern "C" {
#endif
/*
* Class: MyNative
* Method: greeting
* Signature: ()V
*/
JNIEXPORT void JNICALL Java_MyNative_greeting
(JNIEnv *, jclass);

#ifdef __cplusplus
}
#endif
#endif

3、编写调用的C函数

#include "MyNative.h"
#include <stdio.h>

JNIEXPORT void JNICALL Java_MyNative_greeting
(JNIEnv * env, jclass cl)
{
printf("Hello Native!/n");
return;
}

编译出库文件

windows：

cl -ID:/jdk/jdk1.5.0_06/include -ID:/jdk/jdk1.5.0_06/include/win32 -LD
MyNative.c -FeMyNative.dll

linux

gcc -c -fPIC -I/opt/jdk1.5.0_06/include -I/opt/jdk1.5.0_06/include/linux MyNative.c
gcc -shared -o libMyNative.so MyNative.o