初學Socket編程

初學了Socket編程，有什麼不對的地方，請多多指教。

學習了一下Socket，爲了方便以後複習，就寫了這篇博客。

理論的就不多講了，初學了一下socket，就寫了一個例子，一個客戶端，一個服務器端。

服務器端：

package com.seehope.socket;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
//服務器端，多線程併發實現多個客戶端請求服務器
public class ServerThread extends Thread {
	
	private Socket sk;
	//構造方法
	public ServerThread(Socket sk) {
		this.sk = sk;
	}

	@Override
	public void run() {
		InputStream in = null;
		OutputStream os = null;
		PrintStream ps = null; 
		BufferedReader br = null;
		try {
			//獲得輸入輸出低端流
			in = sk.getInputStream();
			os = sk.getOutputStream();
			
			br = new BufferedReader(new InputStreamReader(in));
			//輸出流，輸出的是字節流，若要輸出字符，使用PrintWriter。PrintStream 永遠不會拋出 IOException
			ps = new PrintStream(os);
			boolean flag = true;
			while(flag){
				String line = br.readLine();
				ps.println("服務器說："+line);
				if("bye".equals(line)){
					flag = false;
				}
				//返回給客戶端
				ps.flush();
			}
			ps.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	public static void main(String[] args) throws IOException{
		Socket socket = null;
		ServerSocket serverSocket = new ServerSocket(8899);
		System.out.println("服務器正在監聽...");
		while(true){
			socket = serverSocket.accept();//阻塞，監聽客戶端的請求
			System.out.println(socket.getRemoteSocketAddress()+" 鏈接成功！");
			ServerThread st = new ServerThread(socket);
			//啓動線程
			st.start();
		}
	}
}

客戶端：

package com.seehope.socket;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintStream;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Scanner;

//客戶端
public class ClientSocket {
	public static void main(String[] args) {
		InputStream in = null;
		OutputStream os = null;
		PrintStream ps = null; 
		BufferedReader br = null;
		System.out.println("------客戶端程序-----");
		try {
			//創建socket實例，設置ip地址和要監聽的端口
			Socket socket = new Socket("127.0.0.1",8899);
			os = socket.getOutputStream();
			ps = new PrintStream(os);
			
			in = socket.getInputStream();
			br = new BufferedReader(new InputStreamReader(in));
			String line = null;
			boolean flag = true;
			while(flag){
				Scanner scanner = new Scanner(System.in);
				System.out.println("請輸入信息：");
				line = scanner.nextLine();
				if("bye".equals(line)){
					flag = false;
				}
				ps.println(line);//寫給服務器
				ps.flush();
				//讀取服務器返回的內容
				System.out.println(br.readLine());
			}
			ps.close();
		} catch (UnknownHostException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}