java一个简单的客户端向服务端发送消息

客户端代码：

package com.chenghu.tcpip;

import java.io.IOException;

import java.io.OutputStream;

import java.net.InetAddress;

import java.net.Socket;

//客户端

public class TcpClientDemo01 {

public static void main(String[] args) {

Socket socket=null;

OutputStream os=null;

try {

//服务器ip

InetAddress serverIP=InetAddress.getByName("127.0.1");

//端口

int port=9999;

//创建链接

socket=new Socket(serverIP,port);

//发送消息 io流

os=socket.getOutputStream();

os.write("你好！".getBytes());

} catch (Exception e) {

e.printStackTrace();

}finally {//关闭资源

if (os != null) {

try {

os.close();

} catch (IOException e) {

e.printStackTrace();

}

}

if (socket != null) {

try {

socket.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}

}

}

服务端代码：

package com.chenghu.tcpip;

import java.io.*;

import java.net.ServerSocket;

import java.net.Socket;

//服务端

public class TcpServerDemo01 {

public static void main(String[] args) {

ServerSocket serverSocket=null;

Socket socket=null;

InputStream is=null;

ByteArrayOutputStream bas=null;

try {

//需要 一个地址

serverSocket= new ServerSocket(9999);

while(true) {

//等待客户端连接

socket = serverSocket.accept();

//读取客户端的消息

is = socket.getInputStream();

//管道流

bas = new ByteArrayOutputStream();

byte[] buffer = new byte[1024];

int len;

while ((len = is.read(buffer)) != -1) {

bas.write(buffer, 0, len);

}

System.out.println(bas.toString());

}

} catch (IOException ex) {

ex.printStackTrace();

}finally {//关闭资源

if (bas != null) {

try {

bas.close();

} catch (IOException e) {

e.printStackTrace();

}

}

if (is != null) {

try {

is.close();

} catch (IOException e) {

e.printStackTrace();

}

}

if (socket != null) {

try {

socket.close();

} catch (IOException e) {

e.printStackTrace();

}

}

if (serverSocket != null) {

try {

serverSocket.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}

}

}

总结一下 ：

客户端：

连接服务器Socket

发送消息

服务器

建立服务端口

等待用户连接accept()；

接收消息