java jni調用 非託管 dll

Step1:

 編寫java類,e.g.:

//filename: HelloWorld.javapublic 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

產生標頭檔如下:

/* DO NOT EDIT THIS FILE - it is machine generated */#include <jni.h>/* Header for class HelloWorld */#ifndef _Included_HelloWorld#define _Included_HelloWorld#ifdef __cplusplusextern "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建立一個win32 dll項目, 項目名hello

Step5:

tools->option->directory(標籤)

directories增加兩個include 路徑(具體看java的實際include路徑):

D:\java\jdk\jdk1.6.0_21\include

D:\java\jdk\jdk1.6.0_21\include\win32

Step6:

建立hello.cpp

#include <jni.h>#include "HelloWorld.h"#include <stdio.h>#include <windows.h>JNIEXPORT void JNICALL Java_HelloWorld_displayHelloWorld  (JNIEnv *, jobject){printf("hello 中國 !@#$");}/** Class:     HelloWorld* Method:    add* Signature: (II)I*/JNIEXPORT jint JNICALL Java_HelloWorld_add(JNIEnv *, jobject, jint a, jint b){return a+b;}