Java网络编程之(二): TCP的多线程连接

相比前面一个例子，这里加入了多线程的操作，服务器可以不断读取客户端数据，并向客户端写入数据；客户端也可以不断的读取服务器数据，并向服务器写入数据。支持多客户端，功能实际就是一个基于Socket的TCP简易聊天程序，服务端实现了消息的转发。

局域网中电脑A用作服务端，IP为192.168,31.168

同时电脑A中开启另一个终端作为一个客户端

电脑B用作客户端，IP为192.168.31.132

TCP服务端:

package cn.com.tcpthread;

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;

public class TcpServer_2 {
	//定义保存所有Socket的ArrayList
	public static ArrayList<Socket> socketList = new ArrayList<Socket>();
	public static void main(String[] args) throws IOException {
		ServerSocket ss = new ServerSocket(30001);
		while(true)
		{
			//此行代码会阻塞，将一直等待别人的连接
			Socket s = ss.accept();
			socketList.add(s);
			//每当客户端连接后，启动一条ServerThread线程为该客户端服务
			new Thread(new ServerThread(s)).start();
		}
	}


}

TCP服务端线程实现:

package cn.com.tcpthread;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintStream;
import java.net.Socket;

public class ServerThread implements Runnable{
	//定义当前线程所处理的Scoket
	Socket s = null;
	//该线程所处理的Socket所对应的输入流
	BufferedReader br = null;
	//String line=null;
	public ServerThread(Socket s) throws IOException {
		this.s = s;
		//初始化该Socket对应的输入流
		br = new BufferedReader(new InputStreamReader(s.getInputStream()));
	}
		public void run() {
			try
			{
				String connect = null;
				//采用循环不断从Socket中读取客户端送过来的数据
				while((connect = readFromClient()) != null)
				{
					//遍历socketList中的每个Socket,将读到的内容向每个Socket发送一次
					for(Socket s: TcpServer_2.socketList)
					{
						//输出流
						PrintStream ps = new PrintStream(s.getOutputStream());
						System.out.println(connect);
						ps.println(connect);
						//不断读取键盘输入
						BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
						//line=null;
						//ps.println(connect);
						while((connect=br.readLine()) != null)
						{
							//将用户的键盘输入内容写入Socket对应的输出流
							ps.println(connect);
							//break;
							//System.out.println(connect);
						}
						//break;
					}
				}
				
			}catch(Exception e)
			{
				e.printStackTrace();
			}
			
		}
		//定义读取客户端数据的方法
		private String readFromClient()
		{
			try
			{
				return br.readLine();
			}
			//如果捕捉到异常，表明该Socket对应的客户端已经关闭
			catch(IOException e)
			{
				//删除该Socket
				TcpServer_2.socketList.remove(s);
			}
			return null;
		}
		
	}

TCP客户端:

package cn.com.tcpthread;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.Socket;
import java.net.UnknownHostException;

public class TcpClient_2 {
	/**
	 * 客户端
	 * @param args
	 * @throws IOException 
	 * @throws UnknownHostException 
	 */
	public static void main(String[] args) throws UnknownHostException, IOException {
		Socket s = new Socket("192.168.1.101", 30001);
		//客户端启动ClientThread线程不断读取来自服务器的数据
		new Thread(new ClientThread(s)).start();
		//获取该Socket对应的输出流
		PrintStream ps = new PrintStream(s.getOutputStream());
		//ps.print("123123123");
		String line = null;
		//不断读取键盘输入
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		while((line=br.readLine()) != null)
		{
			//将用户的键盘输入内容写入Socket对应的输出流
			ps.println(line);
		}

	}

}

TCP客户端线程:

package cn.com.tcpthread;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.Socket;
 
public class ClientThread implements Runnable
{
	//该线程负责处理的Socket
	private Socket s;
	//该线程所处理的Socket所对应的输入流
	BufferedReader br = null;
	public ClientThread(Socket s)throws IOException
	{
		this.s = s;
		br = new BufferedReader(new InputStreamReader(s.getInputStream()));
	}
	public void run()
	{
		try
		{
			String connect = null;
			//不断读取Socket输入流中的内容，并将这些内容打印输出
			while((connect = br.readLine()) != null)
			{
				System.out.println(connect);
			}
		}catch(Exception e)
		{
			e.printStackTrace();
		}
	}
}