Java JNI 简单实践

cn_fantasticmao_jni_SumNative.c

#include <jni.h>
#include "cn_fantasticmao_jni_SumNative.h"

/*
 * Class:     cn_fantasticmao_jni_SumNative
 * Method:    sum
 * Signature: (II)I
 */
JNIEXPORT jint JNICALL Java_cn_fantasticmao_jni_SumNative_sum
  (JNIEnv *env, jobject obj, jint a, jint b)
{
  return a + b;
}

cn_fantasticmao_jni_SumNative.h

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

#ifndef _Included_cn_fantasticmao_jni_SumNative
#define _Included_cn_fantasticmao_jni_SumNative
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     cn_fantasticmao_jni_SumNative
 * Method:    sum
 * Signature: (II)I
 */
JNIEXPORT jint JNICALL Java_cn_fantasticmao_jni_SumNative_sum
  (JNIEnv *, jobject, jint, jint);

#ifdef __cplusplus
}
#endif
#endif

SumNative.java

package cn.fantasticmao.jni;

public class SumNative {

    static {
        System.loadLibrary("sum");
    }

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

    public static void main(String[] args) {
        int value = new SumNative().sum(1, 2);
        System.out.printf("1 + 2 = %d%n", value);
    }
}