JNI

package org.jxch.study;

public class Demo {
    static {
        System.loadLibrary("DemoNative");
    }
    
    private native void demo();
    
    // 回调 Java 方法
    private void callback() {
        System.out.println("callback");
    }
}

编译头文件 javac -h . Demo.java

编写 demo.c:

#include "org_jxch_study_Demo.h"

org_jxch_study_Demo_demo(JNIEnv *env, jobject c1) {
    printf("netive demo/n");
	
    jclass thisClass = (*env)->GetObjectClass(env, c1);
    //根据方法名和签名获取方法的id
    jmethodID midCallBack = (*env)->GetMethodID(env, thisClass, "callback", "()V");
    //调用方法
    (*env)->CallVoidMethod(env, c1, midCallBack);
}

生成 so 文件:

gcc -fPIC -I /...jdk.../include -I /...jdk.../include/linux -shared -o DemoNative.so demo.c

添加到环境变量：

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/...demo.c 所在目录...