JNA 执行so库

Cmake编译so库 ,JNA执行so

项目结构如图

头文件

#include <stdio.h>
#include <stdio.h>

int add(int a,int b);

int multiply(int a,int b);

int minus(int a,int b);

int divide(int a,int b);

实现文件

#include "c_fun.h"
#include <jni.h>
#include <stdio.h>
// cc -c fun_main.c  => fun_main.o

// 将.o 文件 => *.so
// cc -shared -o libCFun.so c_fun.o

// nm libCfun.so nm命令查看so文件里的方法声明

int add(int a,int b){
	return a + b;
}

int multiply(int a,int b){
	return a * b;
}

int minus(int a,int b){
	return a - b;
}

int divide(int a,int b){
    if(b == 0 ){
        return -1;
    }
	return a / b;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.18)

set(CMAKE_CXX_STANDARD 11)

#aux_source_directory(. src )
#aux_source_directory(. include )

project(CFun) # 项目名称

set(LINK_JNI_DIR /Library/Java/JavaVirtualMachines/jdk1.8.0_65.jdk/Contents/Home/include )
set(LINK_JMI_DIR /Library/Java/JavaVirtualMachines/jdk1.8.0_65.jdk/Contents/Home/include/darwin )

# 收集c/c++文件并赋值给变量SRC_LIST_CPP  ${PROJECT_SOURCE_DIR}代表区当前项目录
file(GLOB SRC_LIST_CPP ${PROJECT_SOURCE_DIR}/src/*.cpp)
file(GLOB SRC_LIST_C ${PROJECT_SOURCE_DIR}/src/*.c)

# 指定头文件目录
include_directories(${PROJECT_SOURCE_DIR}/include)
# 包含第三方头文件，这里包含jni.h、jni_md.h头文件路径
include_directories(${LINK_JNI_DIR} ${LINK_JMI_DIR})

#打印
#message ("${PROJECT_SOURCE_DIR}")

# 指定生成库文件的目录
set(LIBRARY_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/lib)


link_directories(${LINK_JNI_DIR} ${LINK_JMI_DIR})

find_library(${PROJECT_SOURCE_DIR}/include ${LINK_JNI_DIR} ${LINK_JMI_DIR})

# 取变量SRC_LIST_CPP 与 SRC_LIST_C的值

set(LIBRARY_OUTPUT_PATH ${CMAKE_SOURCE_DIR}/lib)

# SHARED => 为.dylib文件
#add_library(CFun SHARED  ${SRC_LIST_CPP} ${SRC_LIST_C}  ${LINK_JNI_DIR} ${LINK_JMI_DIR} )

# MODULE => 为.so文件
add_library(CFun MODULE ${SRC_LIST_CPP} ${SRC_LIST_C}  ${LINK_JNI_DIR} ${LINK_JMI_DIR} )

# STATIC => 为.a文件
#add_library(CFun STATIC ${SRC_LIST_CPP} ${SRC_LIST_C} ${LINK_JNI_DIR} ${LINK_JMI_DIR})

• 在c_fun目录执行命令:
  $root> mkdir build && cd build && cmake .. && make
  然后得到libCFun.so文件,存放目录在c_fun/lib下

Java JNA调用该so动态库

1. 添加依赖jar

   <dependency>
       <groupId>net.java.dev.jna</groupId>
       <artifactId>jna</artifactId>
       <version>5.3.1</version>
   </dependency>

JnaLibrary.java => 申明接口与so对应关系

import com.sun.jna.Library;
import com.sun.jna.Native;

public interface JnaLibrary extends Library {
    JnaLibrary INSTANCE = Native.load("/Users/iriszhang/Documents/java_workspace/JNADemo/c_fun/lib/libCfun.so", JnaLibrary.class);
    int add(int a,int b);
    int multiply(int a,int b);
    int minus(int a,int b);
    int divide(int a,int b);
    String getSalt();
}

JNAMain.java

public class JnaMain {
    public static void main(String args[]){
        int a = 200,b=100;
        int add = JnaLibrary.INSTANCE.add(a, b);
        int multiply = JnaLibrary.INSTANCE.multiply(a, b);
        int minus = JnaLibrary.INSTANCE.minus(a, b);
        int divide = JnaLibrary.INSTANCE.divide(a, b);
        // out: 200
        System.out.println(add);
        // out: 20000
        System.out.println(multiply);
        // out: 100
        System.out.println(minus);
        // out: 2
        System.out.println(divide);
    }
}