java jni调用 非托管 dll
Step1:
编写java类,e.g.:
//filename: HelloWorld.java
public class HelloWorld{
public native void displayHelloWorld();
public native int add(int a,int b);
static {
System.loadLibrary("hello");
}
public static void main(String[] args){
HelloWorld hw=new HelloWorld();
hw.displayHelloWorld();
System.out.println();
System.out.println(" 1+20= "+ hw.add(1,20) );
}
}
Step2: javac HelloWorld.java
Step3: javah HelloWorld
生成头文件如下:
/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class HelloWorld */
#ifndef _Included_HelloWorld
#define _Included_HelloWorld
#ifdef __cplusplus
extern "C" {
#endif
/*
* Class: HelloWorld
* Method: displayHelloWorld
* Signature: ()V
*/
JNIEXPORT void JNICALL Java_HelloWorld_displayHelloWorld
(JNIEnv *, jobject);
/*
* Class: HelloWorld
* Method: add
* Signature: (II)I
*/
JNIEXPORT jint JNICALL Java_HelloWorld_add
(JNIEnv *, jobject, jint, jint);
#ifdef __cplusplus
}
#endif
#endif
Step4:用vc6建立一个win32 dll项目, 项目名hello
Step5:
tools->option->directory(标签)
directories增加两个include 路径(具体看java的实际include路径):
D:\java\jdk\jdk1.6.0_21\include
D:\java\jdk\jdk1.6.0_21\include\win32
Step6:
新建hello.cpp
#include <jni.h>
#include "HelloWorld.h"
#include <stdio.h>
#include <windows.h>
JNIEXPORT void JNICALL Java_HelloWorld_displayHelloWorld
(JNIEnv *, jobject)
{
printf("hello 中国 !@#$");
}
/*
* Class: HelloWorld
* Method: add
* Signature: (II)I
*/
JNIEXPORT jint JNICALL Java_HelloWorld_add
(JNIEnv *, jobject, jint a, jint b){
return a+b;
}