Thao tác với DLL bằng Java

JNI architecture

Calling JNI

public native int add(int a, int b);

public static void main(String[] args) {

Calculator cal = new Calculator();

int sum = cal.add(1,2);

}

javac Calc.java

javah -jni Calc

#include

/* Header for class Calculator */

#ifndef _Included_Calculator

#define _Included_Calculator

#ifdef __cplusplus

extern “C” {

#endif

/*

* Class: Calculator

* Method: add

* Signature: (II)I

*/

JNIEXPORT jint JNICALL Java_Calculator_add

(JNIEnv *, jobject, jint, jint);

#ifdef __cplusplus

} #

endif

#endif

#include

#include “Calc.h”

JNIEXPORT jint JNICALL

Java_Calc_add(JNIEnv *env, jobject obj, jint a, jint b)

{

return a + b;

}

○ file Calc.java

package Calculator;

import com.sun.jna.*;

public interface Calc extends Library {

int add(int a, int b);

}

○ file Cal.java

package Calculator;

import com.sun.jna.*;

public class Cal {

static Calc init() {

Calc c = (Calc) Native.loadLibrary(“Path/to/Calc”,

Calc.class);

return c;

} public static void main (

String [] args) {

System.out.println(add(1, 2));

} public static int add(int a, int b) {

return init().add(a, b);

} public static int substract(int a, int b) {

return init().substract(a, b);

}

}