一、JNI 入门教程
1.编写java测试类
package com.liu.jni;
public class JNILibrary {
public native static void show();
public native static int calc(int a, int b);
static {
System.loadLibrary("libshared_jni");
}
}
package com.liu.jni;
public class JNITest {
public static void main(String[] args) {
JNILibrary.show();
System.out.println(JNILibrary.calc(3, 5));
}
}
2.利用java类生成C头文件
cmd进入class文件根目录：
cd D:\jps-workspace\jni_jna\target\classes
执行命令：
javah -classpath . -jni com.liu.jni.JNILibrary
重命名com.liu.jni.JNILibrary.h为JNILibrary.h
3.编译生成C++动态库
创建动态库project：
复制JNILibrary.h到C++动态库project:
JNILibrary.h代码：
/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class com_liu_jni_JNILibrary */
#ifndef _Included_com_liu_jni_JNILibrary
#define _Included_com_liu_jni_JNILibrary
#ifdef __cplusplus
extern "C" {
#endif
/*
* Class: com_liu_jni_JNILibrary
* Method: show
* Signature: ()V
*/
JNIEXPORT void JNICALL Java_com_liu_jni_JNILibrary_show
(JNIEnv *, jclass);
/*
* Class: com_liu_jni_JNILibrary
* Method: calc
* Signature: (II)I
*/
JNIEXPORT jint JNICALL Java_com_liu_jni_JNILibrary_calc
(JNIEnv *, jclass, jint, jint);
#ifdef __cplusplus
}
#endif
#endif
JNIShared.cc代码：
#include <iostream>
#include "JNILibrary.h"
using namespace std;
JNIEXPORT void JNICALL Java_com_liu_jni_JNILibrary_show(JNIEnv *, jclass) {
cout << "JNI Shared Library." << endl;
}
JNIEXPORT jint JNICALL Java_com_liu_jni_JNILibrary_calc(JNIEnv *, jclass,
jint a, jint b) {
return a + b;
}
然后编译生成动态库：
4.添加动态库到jni_jna
复制libshared_jni.dll到jni_jna工程
目录
然后设置动态库位置：
5.测试JNITest
二、JNA入门教程
1.编写java测试类
package com.liu.jna;
import com.sun.jna.Library;
import com.sun.jna.Native;
public interface JNALibrary extends Library {
JNALibrary INSTANCE = (JNALibrary) Native.loadLibrary("libshared_jna", JNALibrary.class);
void show();
int calc(int a, int b);
}
package com.liu.jna;
public class JNATest {
public static void main(String[] args) {
JNALibrary.INSTANCE.show();
System.out.println(JNALibrary.INSTANCE.calc(3, 5));
}
}
2.编译生成C++动态库
创建动态库project同上
JNAShared.cc代码：
#include <iostream>
using namespace std;
extern "C" __declspec(dllexport) void show();
extern "C" __declspec(dllexport) int calc(int a, int b);
void show() {
cout << "JNA Shared Library." << endl;
}
int calc(int a, int b) {
return a + b;
}
然后编译生成动态库：
3.添加动态库到jni_jna
复制libshared_jna.dll到jni_jna工程目录
4.测试JNATest
实例源码：