linux 环境下java 使用jna调用so库方法

一、下载jna.jar

https://github.com/java-native-access/jna

二 、jna使用的官方文档如下

http://java-native-access.github.io/jna/4.2.1/

三、编写so代码如下

/*
 * =====================================================================================
 *
 *       Filename:  TestDll1.cpp
 *
 *    Description:  
 *
 *        Version:  1.0
 *        Created:  2015年12月24日 22时50分22秒
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  yifan (), [e-mail]
 *   Organization:  
 *
 * =====================================================================================
 */
#include <string.h>
#include <wchar.h>

#define MYLIBAPI extern "C"  

MYLIBAPI void say(wchar_t *pValue);

struct UserStruct{
    long     id;
    wchar_t    *name;
    int     age;
};

MYLIBAPI void sayUser(UserStruct *pUserStruct);

struct CompanyStruct{
    long     id;
    wchar_t *name;
    UserStruct users[100];
    int count;
};

struct CompanyStruct2{
    long     id;
    wchar_t    *name;
    UserStruct *users[100];
    int count;
};
#pragma pack(1)
struct NestedStruct{
    char pwd[16];
    char key[16];
    char padding[113];
};

struct SimpleStruct{
    NestedStruct nested;
    int a;
    unsigned char b;
    int c;
    int d;
    char name[100];
};
#pragma pack()
MYLIBAPI void sayCompany(CompanyStruct* pCompanyStruct);
MYLIBAPI void sayCompany2(CompanyStruct2 *pCompanyStruct);
MYLIBAPI void getCompany(CompanyStruct *pCompanyStruct);
MYLIBAPI void getSimpleStruct(SimpleStruct *simp);
MYLIBAPI void saySimpleStruct(SimpleStruct *simp);

#include <iostream>

void say(wchar_t *pValue){
    std::wcout<<L"上帝说: "<<pValue<<std::endl;
}

void sayUser(UserStruct *pUserStruct){

    std::wcout<<L"ID: "<<pUserStruct->id<<std::endl;
    std::wcout<<L"姓名: "<<pUserStruct->name<<std::endl;
    std::wcout<<L"年龄: "<<pUserStruct->age<<std::endl;
}

void sayCompany(CompanyStruct *pCompanyStruct){

    std::wcout<<L"ID: "<<pCompanyStruct->id<<std::endl;
    std::wcout<<L"公司名称: "<<pCompanyStruct->name<<std::endl;
    std::wcout<<L"员工总数: "<<pCompanyStruct->count<<std::endl;

    for (int i = 0; i < pCompanyStruct->count; i++){
        sayUser(&pCompanyStruct->users[i]);
    }

}

void sayCompany2(CompanyStruct2 *pCompanyStruct){


    std::wcout<<L"ID: "<<pCompanyStruct->id<<std::endl;
    std::wcout<<L"公司名称: "<<pCompanyStruct->name<<std::endl;
    std::wcout<<L"员工总数: "<<pCompanyStruct->count<<std::endl;

    for (int i = 0; i < pCompanyStruct->count; i++){
        sayUser(pCompanyStruct->users[i]);
    }
}

void getCompany(CompanyStruct *pCompanyStruct){
    pCompanyStruct->count = 1;
    wcscpy(pCompanyStruct->name, L"Out Name");
    pCompanyStruct->id = 13;
}

void getSimpleStruct(SimpleStruct *simp){
    simp->a = 1;
    simp->b = 2;
    simp->c = 3;
    simp->d = 4;
    memset(simp->name, 0, sizeof(simp->name));
    strcpy(simp->name, "test");
    memset(&simp->nested, 0, sizeof(NestedStruct));
    strcpy(simp->nested.pwd, "pwd");
    strcpy(simp->nested.key, "key");
}

void saySimpleStruct(SimpleStruct *simp){
    std::wcout<<L"simp->a = "<<simp->a<<std::endl;
    std::wcout<<L"simp->b = "<<simp->b<<std::endl;
    std::wcout<<L"simp->c = "<<simp->c<<std::endl;
    std::wcout<<L"simp->d = "<<simp->d<<std::endl;
    std::wcout<<L"simp->name = "<<simp->name<<std::endl;
    std::wcout<<L"simp->nested.pwd ="<<simp->nested.pwd<<std::endl;
    std::wcout<<L"simp->nested.key ="<<simp->nested.key<<std::endl;
}

 

四、编写java测试代码如下：

//package com.sun.jna;


import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;


import com.sun.jna.Library;
import com.sun.jna.Native;
import com.sun.jna.NativeLong;
import com.sun.jna.Structure;
import com.sun.jna.WString;
 

public class TestDll1Service {

     /*
      * 定义一个类，模拟C语言的结构
      * 
      */
        
       public static class UserStruct extends Structure{
          
            public static class ByReference extends UserStruct implements Structure.ByReference {
                public ByReference() {}
                //public ByReference(Pointer p){ super(p);}
            }
            public static class ByValue extends UserStruct implements Structure.ByValue {
                public ByValue() {}
                //public ByValue(Pointer p) { super(p);}
            }
 
           public NativeLong id;
           public WString name;
           public int age;
       
           // 字段顺序与SO中结构体声明一致 
           protected List getFieldOrder() { 
            return Arrays.asList(new String[] { 
            "id", "name", "age"
                });
            }
       }
       
       public static class CompanyStruct extends Structure{
            public static class ByReference extends CompanyStruct implements Structure.ByReference {
                public ByReference() {}
                //public ByReference(Pointer p){ super(p);}
            }
            
            public static class ByValue extends CompanyStruct implements Structure.ByValue {
                public ByValue() {}
                //public ByValue(Pointer p) { super(p);}
            }
          
           public NativeLong id;
           public WString  name;
           // 嵌套的结构体数组,下面三种声明都可以，注意每种声明的赋值方式        
           // Declare 1
           // public UserStruct[] users = (UserStruct[])new UserStruct().toArray(100);
           // Declare 2
           // public UserStruct.ByValue[] users = new UserStruct.ByValue[100]; 
           // Declare 3
           public UserStruct[] users = new UserStruct[100];
           public int count;

           protected List getFieldOrder() { 
            return Arrays.asList(new String[] { 
            "id", "name", "users", "count"
                });
            }
          
          
       }
       
       public static class CompanyStruct2 extends Structure{
           public static class ByReference extends CompanyStruct2 implements Structure.ByReference {
                public ByReference() {}
                //public ByReference(Pointer p){ super(p);}
           }
           
           public static class ByValue extends CompanyStruct2 implements Structure.ByValue {
                public ByValue() {}
                //public ByReference(Pointer p){ super(p);}
            }
            
           public NativeLong id;
           public WString  name;
             // 嵌套的结构体指针数组
           public UserStruct.ByReference[] users=new UserStruct.ByReference[100];
           public int count;
           
           protected List getFieldOrder() { 
            return Arrays.asList(new String[] { 
            "id", "name", "users", "count"
                });
            }
          
          
       }

       public static class NestedStruct extends Structure{
               public static class ByValue extends NestedStruct implements Structure.ByValue{}
               // 声明内存对齐方式，与SO中声明的结构体对齐保持一致
            public NestedStruct() {super(ALIGN_NONE);}

            // 注意C/C++中的char 对应java中的byte,其它类型之间的映射请参考官方文档
            public byte pwd[] = new byte[16];
            public byte key[] = new byte[16];
            public byte padding[] = new byte[113];

            protected List getFieldOrder(){
                return Arrays.asList(new String[]{
                    "pwd", "key", "padding"});
            }
       }
       
       public static class SimpleStruct extends Structure{
        public static class ByReference extends SimpleStruct implements Structure.ByReference{}   
        public NestedStruct.ByValue nested = new NestedStruct.ByValue();
           public int a;
           public byte b;
           public int c;
           public int d;
        public byte name[] = new byte[100];

        public SimpleStruct(){super(ALIGN_NONE);};
           protected List getFieldOrder(){
               return Arrays.asList(new String[]{
               "nested", "a", "b", "c", "d", "name"
               });
        }
       }

       
        public interface TestDll1 extends Library {
           /**
            * 当前路径是在项目下，而不是bin输出目录下。
            */
            TestDll1 INSTANCE = (TestDll1)Native.loadLibrary("TestDll1", TestDll1.class);
          
          
            public void say(WString value);
       
      
              
            public void sayUser(UserStruct.ByReference struct);
          
           
          
             public   void sayCompany(CompanyStruct.ByReference pCompanyStruct);
          
            public void sayCompany2(CompanyStruct2.ByReference  pCompanyStruct);
            
            //public void getCompany(CompanyStruct.ByReference pCompanyStruct);
            public void getSimpleStruct(SimpleStruct simp);
            public void getSimpleStruct(SimpleStruct.ByReference simp);
            public void saySimpleStruct(SimpleStruct simp);
            
        }
    public class TestClass{
        int a;
        int b;
    }
    
 
    /**
     * @param args
     */
    public static void main(String[] args) {
       // TODO Auto-generated method stub
     
       TestDll1.INSTANCE.say(new WString("Hello World!"));
       System.out.println("HHEEH中文");
      
       
       UserStruct.ByReference userStruct = new UserStruct.ByReference();
       userStruct.id = new NativeLong(100);
       userStruct.age = 30;
       userStruct.name = new WString("yifan");
       TestDll1.INSTANCE.sayUser(userStruct);
       System.out.println("AAAAAAAAAAAAAAAAAAAAAAAAAAA");
      
       CompanyStruct.ByReference companyStruct = new CompanyStruct.ByReference();
       companyStruct.id = new NativeLong(1);
       companyStruct.name = new WString("Google");
       companyStruct.count = 9;
       System.out.println("UserStruct size = " + userStruct.size());
       System.out.println("CompanyStruct size = " + companyStruct.size());
       for(int i = 0; i < companyStruct.count; i++){
           /*
            * Declare 1
           companyStruct.users[i].id = new NativeLong(i);
           companyStruct.users[i].name = new WString("yifan" + i);
           companyStruct.users[i].age = 20 + i;
           */
           /*
            * Declare 2
           UserStruct.ByValue user = new UserStruct.ByValue();
           user.id = new NativeLong(i + 1);
           user.name = new WString("yifan" + i);
           user.age = 20 + i;
           companyStruct.users[i] = user;
           */
           /*
            * Declare 3
            */
           UserStruct user2 = new UserStruct();
           user2.id = new NativeLong(i);
           user2.name = new WString("yifan " + i);
           user2.age = 20 + i;
           companyStruct.users[i] = user2;
       }
       TestDll1.INSTANCE.sayCompany(companyStruct); 
       
       System.out.println("++++++++++++++");
       
       CompanyStruct2.ByReference companyStruct2 = new CompanyStruct2.ByReference();
       companyStruct2.id = new NativeLong(2);
       companyStruct2.name = new WString("Yahoo");
       companyStruct2.count = 10;
       System.out.println("CompanyStruct2 size = " + companyStruct2.size());
       for(int i = 0;i < companyStruct2.count; i++){
            companyStruct2.users[i] = new UserStruct.ByReference();
               companyStruct2.users[i].id = new NativeLong(i);
            companyStruct2.users[i].name = new WString("Yahoo user" + i);
            companyStruct2.users[i].age = 20 + i;
       }
       //companyStruct.write(); 
       TestDll1.INSTANCE.sayCompany2(companyStruct2);
       
       System.out.println("CCCCCCCCCCCCCCCCCCCCCCCCCCCC");
       SimpleStruct.ByReference simple = new SimpleStruct.ByReference();
       TestDll1.INSTANCE.getSimpleStruct(simple);
       System.out.println("simple: size = " + simple.size());
       System.out.println("simple: a = " + simple.a);       
       System.out.println("simple: b = " + simple.b); 
       System.out.println("simple: c = " + simple.c);
       System.out.println("simple: d = " + simple.d);
       System.out.println("simple: name = " + new String(simple.name));
       System.out.println("simple: nested: pwd = " + new String(simple.nested.pwd));
       System.out.println("simple: nested: key = " + new String(simple.nested.key));
       System.out.println("DDDDDDDDDDDDDDDDDDDDDDDDDDDDDD");
       
       SimpleStruct simp2 = new SimpleStruct();
       byte[] pwd = "simp2_pwd".getBytes();
       byte[] key = "simp2_key".getBytes();
       byte[] name = "simp2".getBytes();
       simp2.a = 5;
       simp2.b = 6;
       simp2.c = 7;
       simp2.d = 8;
       //
       // 对于已经声明大小的数组，使用下面数组赋值方式，
       // 不要使用simp2.nested.pwd = "11".getBytes() 这种赋值方式
       // 
      
       System.arraycopy(name, 0, simp2.name, 0, name.length);
       System.arraycopy(pwd, 0, simp2.nested.pwd, 0, pwd.length);
       System.arraycopy(key, 0, simp2.nested.key, 0, key.length);
       TestDll1.INSTANCE.saySimpleStruct(simp2);
       System.out.println("EEEEEEEEEEEEEEEEEEEEEEEEEEEEE");

      
    }
 
}

 

五、编译代码

　　由于本人没有安装Java相关IDE,使用命令行进行编译运行。

　　1、编译so库

　　

g++ -fPIC -shared -o libTestDll1.so TestDll1.cpp

　　2、编译java，将下载的jna放到测试的代码目录

 javac -classpath jna-4.2.1.jar TestDll1Service.java

　　3、运行class 文件

java -classpath .:jna-4.2.1.jar TestDll1Service

　　4、运行结果如下

上帝说: Hello World!
HHEEH中文
ID: 100
姓名: yifan
年龄: 30
AAAAAAAAAAAAAAAAAAAAAAAAAAA
UserStruct size = 24
CompanyStruct size = 2424
ID: 1
公司名称: Google
员工总数: 9
ID: 0
姓名: yifan0
年龄: 20
ID: 1
姓名: yifan1
年龄: 21
ID: 2
姓名: yifan2
年龄: 22
ID: 3
姓名: yifan3
年龄: 23
ID: 4
姓名: yifan4
年龄: 24
ID: 5
姓名: yifan5
年龄: 25
ID: 6
姓名: yifan6
年龄: 26
ID: 7
姓名: yifan7
年龄: 27
ID: 8
姓名: yifan8
年龄: 28
++++++++++++++
ID: 2
公司名称: Yahoo
员工总数: 10
ID: 0
姓名: Yahoo user0
年龄: 20
ID: 1
姓名: Yahoo user1
年龄: 21
ID: 2
姓名: Yahoo user2
年龄: 22
ID: 3
姓名: Yahoo user3
年龄: 23
ID: 4
姓名: Yahoo user4
年龄: 24
ID: 5
姓名: Yahoo user5
年龄: 25
ID: 6
姓名: Yahoo user6
年龄: 26
ID: 7
姓名: Yahoo user7
年龄: 27
ID: 8
姓名: Yahoo user8
年龄: 28
ID: 9
姓名: Yahoo user9
年龄: 29
CCCCCCCCCCCCCCCCCCCCCCCCCCCC
simple: size = 258
simple: a = 1
simple: b = 2
simple: c = 3
simple: d = 4
simple: name = test
simple: nested: pwd = pwd
simple: nested: key = key
DDDDDDDDDDDDDDDDDDDDDDDDDDDDDD
simp->a = 5
simp->b = 6
simp->c = 7
simp->d = 8
simp->name = simp2
simp->nested.pwd =simp2_pwd
simp->nested.key =simp2_key