Mac under Java JNI (Java Native Interface) c

1. Writing a Java class with a native declaration method

2. Compiling Java classes using the Javac command

3. Use the Java-jni className to generate a header file with the suffix named. h

4. Implementing local methods using other languages (c, C + +)

5. Generate a dynamic-link library of files written by local methods

One code: (Do not take the package path)

/**
* Native-0study
*
* @author Xuedui.zhao
* @create 2018-04-23
*/
public class HelloWorld {
    public native void Hello ();

    static{
        System.loadlibrary ("Hello");
    }

    public static void Main (string[] args) {

        New HelloWorld (). hello ();
    }
}

Two:

In terminal execution: Javac Helloworld.java

The Helloworld.class file is generated

Three: Use Java-jni className to generate header file with suffix. h

/* Don't EDIT this file-it are machine generated */
#include <jni.h>
/* Header for class HelloWorld */

#ifndef _included_helloworld
#define _included_helloworld
#ifdef __cplusplus
extern "C" {
#endif
/*
* Class:     HelloWorld
* Method:    Hello
* Signature: () V
*/
jniexport void Jnicall Java_helloworld_hello
  (JNIENV *, jobject);

#ifdef __cplusplus
}
#endif
#endif

IV: Create a HELLOWORLDIMPL.C file

#include "jni.h"
#include "HelloWorld.h"
#include <stdio.h>
Jniexport void Jnicall Java_helloworld_hello (jnienv *env,jobject obj) {
  printf ("Hello world!\n");
  Return
}

V: Generate a dynamic-link library of files written by local methods

Gcc-dynamiclib-i/library/java/javavirtualmachines/jdk1.8.0_162.jdk/contents/home/include Helloworldimpl.c-o Libhello.jnilib
An exception is thrown at this point:

Helloworldimpl.c:1:10:fatal error: ' jni.h ' File not found
#include "jni.h"
^~~~~~~
1 Error generated.

VI: sudo cp/library/java/javavirtualmachines/jdk1.8.0_162.jdk/contents/home/include/darwin/jni_md.h/library/java/ Javavirtualmachines/jdk1.8.0_162.jdk/contents/home/include

Seven: Ls-al

Drwxr-xr-x 7 Xuedui.zhao Staff 224 4 23 21:35.

Drwxr-xr-x 9 Xuedui.zhao Staff 288 4 23 11:52..

-rw-r--r--1 Xuedui.zhao Staff 442 4 14:07 Helloworld.class
-rw-r--r--1 Xuedui.zhao Staff 377 4 14:07 HelloWorld.h
-rw-r--r--1 Xuedui.zhao Staff 276 4 14:06 Helloworld.java
-rw-r--r--1 Xuedui.zhao Staff 4 21:27 HELLOWORLDIMPL.C
-rwxr-xr-x 1 Xuedui.zhao Staff 8400 4 21:35 libhello.jnilib

Eight: Terminal execution: Java HelloWorld

Hello world!

Mac under Java JNI (Java Native Interface) c