Question

用java多线程实现服务器与客户端原理

请教！

Answer 1

服务器端：
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import java.net.*;
import java.util.Vector;
public class OneToMoreServer extends JFrame implements ActionListener{
JPanel contentPane;
JLabel jLabel2 = new JLabel();
JTextField jTextField2 = new JTextField("4700");
JButton jButton1 = new JButton();
JLabel jLabel3 = new JLabel();
JTextField jTextField3 = new JTextField();
JButton jButton2 = new JButton();
JScrollPane jScrollPane1 = new JScrollPane();
JTextArea jTextArea1 = new JTextArea();
ServerSocket server = null;
Socket socket = null;BufferedReader instr =null;PrintWriter os=null ;
Vector vector=new Vector();
boolean serverRun=true;
boolean clientRun=true;
//Construct the frame
public OneToMoreServer() {
jbInit();

}

class MyThread extends Thread{//该线程负责接收数据
Socket socketI=null;
BufferedReader br=null;
public MyThread(Socket socket)
{
socketI=socket;
}
public void run(){
try{
while(clientRun){
this.sleep(100);
br= new BufferedReader(new InputStreamReader(socketI.getInputStream()));
if(br.ready()){ //检查是否有数据
jTextArea1.append("接收到来自客户端("+socketI.getInetAddress().toString()+")的消息: "+br.readLine()+"\n");
}
}
}catch(Exception ex){JOptionPane.showMessageDialog(null,ex.toString());}
}
}

public void actionPerformed(ActionEvent e){
if(e.getSource()==jButton1){
int port=Integer.parseInt(jTextField2.getText().trim());
//监听指定端口
try
{
server = new ServerSocket(port);
new Thread(new ListenClient()).start();
}
catch(IOException ex)
{
JOptionPane.showMessageDialog(null,ex.toString());
}
}
if(e.getSource()==jButton2){
String msg=jTextField3.getText().trim();
if(msg.length()!=0)
sendData("hello");
}
}
//该线程负责监听指定端口
class ListenClient implements Runnable
{
public void run()
{
try{
if(jButton1.getText().trim().equals("侦听")){
jButton1.setText("正在侦听...");
while(serverRun)
{
Socket socketI=server.accept();//有客户端连入时建立一个线程监听客户端发送的消息
vector.add(socketI);
jButton1.setText("正在聊天...");
jTextArea1.append("客户端"+socketI.getInetAddress().toString()+"已经连接到服务器\n");
MyThread t=new MyThread(socketI);
t.start();
}
}
}catch(Exception ex){
JOptionPane.showMessageDialog(null,ex.toString());
}
}
}

private void sendData(String s){//发送数据
try{
for(int i=0;i<vector.size();i++)
{
//怎么广播?????
//向每个客户端发送一条消息
Socket socket=(Socket)vector.get(i);
os= new PrintWriter(socket.getOutputStream());
os.println(s);
os.flush();
}
}catch(Exception ex){
}
}

private void jbInit() {
contentPane = (JPanel) this.getContentPane();
contentPane.setLayout(null);
this.setSize(new Dimension(540, 340));
this.setTitle("服务器");
jLabel2.setBounds(new Rectangle(22, 27, 72, 28));
jLabel2.setText("端口号");
jLabel2.setFont(new java.awt.Font("宋体", 0, 14));
jTextField2.setBounds(new Rectangle(113, 27, 315, 24));

jButton1.setBounds(new Rectangle(440, 28, 73, 25));
jButton1.setFont(new java.awt.Font("Dialog", 0, 14));
jButton1.setBorder(BorderFactory.createEtchedBorder());
jButton1.setActionCommand("jButton1");
jButton1.setText("侦听");
jLabel3.setBounds(new Rectangle(23, 57, 87, 28));
jLabel3.setText("请输入信息");
jLabel3.setFont(new java.awt.Font("宋体", 0, 14));
jTextField3.setBounds(new Rectangle(114, 60, 314, 24));
jTextField3.setText("");
jButton2.setText("广播");
jButton2.setActionCommand("jButton1");
jButton2.setBorder(BorderFactory.createEtchedBorder());
jButton2.setFont(new java.awt.Font("Dialog", 0, 14));
jButton2.setBounds(new Rectangle(440, 58, 73, 25));
jScrollPane1.setBounds(new Rectangle(23, 92, 493, 189));

contentPane.add(jTextField2, null);
contentPane.add(jButton1, null);
contentPane.add(jLabel3, null);
contentPane.add(jTextField3, null);
contentPane.add(jButton2, null);
contentPane.add(jScrollPane1, null);
contentPane.add(jLabel2, null);
jScrollPane1.getViewport().add(jTextArea1, null);
jButton1.addActionListener(this);
jButton2.addActionListener(this);
this.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
try{
socket.close();
instr.close();
System.exit(0);
}catch(Exception ex){
//JOptionPane.showMessageDialog(null,ex.toString());
}

}
});
}
public static void main(String arg[]){
JFrame.setDefaultLookAndFeelDecorated(true);
OneToMoreServer frm=new OneToMoreServer();
frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frm.setVisible(true);
}
}

客户端
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import java.net.*;
public class Client extends JFrame implements ActionListener{
JPanel contentPane;
JLabel jLabel1 = new JLabel();
JTextField jTextField1 = new JTextField("127.0.0.1");
JLabel jLabel2 = new JLabel();
JTextField jTextField2 = new JTextField("4700");
JButton jButton1 = new JButton();
JLabel jLabel3 = new JLabel();
JTextField jTextField3 = new JTextField();
JButton jButton2 = new JButton();
JScrollPane jScrollPane1 = new JScrollPane();
JTextArea jTextArea1 = new JTextArea();
BufferedReader instr =null;
Socket socket = null;
PrintWriter os=null;
public Client() {
jbInit();
}
class MyThread extends Thread{
public void run(){
try{
os=new PrintWriter(socket.getOutputStream());
instr=new BufferedReader(new InputStreamReader(socket.getInputStream()));
while(true)
{
this.sleep(100);
if(instr.ready())
{
jTextArea1.append("接收到来自服务器的消息: "+instr.readLine()+"\n");
}
}
}catch(Exception ex){
JOptionPane.showMessageDialog(null,ex.toString());
}
}
}
public void actionPerformed(ActionEvent e){
if(e.getSource()==jButton1){
String ip=jTextField3.getText().trim();
int port=Integer.parseInt(jTextField2.getText().trim());
connectServer(ip,port);
}
if(e.getSource()==jButton2){
String s=this.jTextField3.getText().trim();
sendData(s);
}
}
private void connectServer(String ip,int port){//连接
try{
if(jButton1.getText().trim().equals("连接")){
jButton1.setText("连接服务器...");
socket=new Socket(ip,port);
jButton1.setText("正在聊天");
MyThread t=new MyThread();
t.start();
}
}catch(Exception ex){
JOptionPane.showMessageDialog(this,ex.toString());
}
}
private void sendData(String s){//发送数据
try{
os = new PrintWriter(socket.getOutputStream());
os.println(s);
os.flush();
this.jTextArea1.append("向服务器发送消息:"+s+"\n");
}catch(Exception ex){
JOptionPane.showMessageDialog(this,ex.toString());
}
}
private void jbInit() {
contentPane = (JPanel) this.getContentPane();
jLabel1.setFont(new java.awt.Font("宋体", 0, 14));
jLabel1.setText("服务器名称");
jLabel1.setBounds(new Rectangle(20, 22, 87, 28));
contentPane.setLayout(null);
this.setSize(new Dimension(540, 340));
this.setTitle("客户端");

jTextField1.setBounds(new Rectangle(114, 26, 108, 24));
jLabel2.setBounds(new Rectangle(250, 25, 72, 28));
jLabel2.setText("端口号");
jLabel2.setFont(new java.awt.Font("宋体", 0, 14));
jTextField2.setBounds(new Rectangle(320, 27, 108, 24));

jButton1.setBounds(new Rectangle(440, 28, 73, 25));
jButton1.setFont(new java.awt.Font("Dialog", 0, 14));
jButton1.setBorder(BorderFactory.createEtchedBorder());
jButton1.setActionCommand("jButton1");
jButton1.setText("连接");
jLabel3.setBounds(new Rectangle(23, 57, 87, 28));
jLabel3.setText("请输入信息");
jLabel3.setFont(new java.awt.Font("宋体", 0, 14));
jTextField3.setBounds(new Rectangle(114, 60, 314, 24));

jButton2.setText("发送");
jButton2.setActionCommand("jButton1");
jButton2.setBorder(BorderFactory.createEtchedBorder());
jButton2.setFont(new java.awt.Font("Dialog", 0, 14));
jButton2.setBounds(new Rectangle(440, 58, 73, 25));
jScrollPane1.setBounds(new Rectangle(23, 92, 493, 189));

contentPane.add(jLabel1, null);
contentPane.add(jTextField1, null);
contentPane.add(jLabel2, null);
contentPane.add(jTextField2, null);
contentPane.add(jButton1, null);
contentPane.add(jLabel3, null);
contentPane.add(jTextField3, null);
contentPane.add(jButton2, null);
contentPane.add(jScrollPane1, null);
jScrollPane1.getViewport().add(jTextArea1, null);
jButton1.addActionListener(this);
jButton2.addActionListener(this);
this.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
try{
socket.close();instr.close();os.close();System.exit(0);
}catch(Exception ex){
JOptionPane.showMessageDialog(null,ex.toString());
}
}
});
}
public static void main(String arg[]){
JFrame.setDefaultLookAndFeelDecorated(true);
Client frm=new Client();
frm.setVisible(true);
}
}

Answer 2

// 在服务器上部署的程序

package wang.socket.Server;
// java 提供的网络功能包
import java.net.*;
// java 提供的输入输出的功能包
import java.io.*;

// 使用线程来处理Socket请求
public class ThreadServer {

public static void main(String[] args) throws Exception {

// 监听服务
ServerSocket server;
// 启动一个监听服务器
server = new ServerSocket(9999);
System.out.println("---------> 一个Socket监听服务器启动：" + server.toString());
while (true) {//循环地响应客户端的请求

//获得客户端连接，也就是要建立一个Socket套接字,由于没有使用线程,多个客户端连接会排队
// ServerSocket的接收套接字的方法是采用队列并等待的方式,如果没有呼入连接,则程序在等待,不向下执行.
Socket client = server.accept();
// 创建线程,让线程去应答客户的请求
new ServerThread(client).start();

}
}
}

// 以线程处理客户的请求
class ServerThread extends Thread {
//主程序的main函数会把创建的Socket作为参数传递给线程执行.

private Socket sk;

public ServerThread(Socket s) {
this.sk = s;
}

@Override
public void run() {
System.out.println("(一个客户请求:)" + this.sk.toString());
// 缓冲区读取器
BufferedReader in;
// 响应器
PrintWriter out;
// 取得客户端的计算机的IP地址
String remoteIP = this.sk.getInetAddress().getHostAddress();
// 取得客户端用于通讯的端口号
int remotePort = this.sk.getLocalPort();
// 在服务器的监控台上显示客户端接入的信息
System.out.println("一个客户端正在连入, IP:" + remoteIP + ", 端口: " + remotePort);

//获得 client 端的输入输出流，为进行交互做准备
try {
in = new BufferedReader(new InputStreamReader(this.sk.getInputStream()));
//获得输出
out = new PrintWriter(this.sk.getOutputStream(), true);

//获得 client 端发送的数据，要注意的是客户端从一个套接字里有可能发送多行的数据。
String content;
// 只有比较明显地给出一个数据流终结的方式才好
while (!(content = in.readLine()).equals("taxend")) {

System.out.println("客户端发来的消息: " + content);
out.println(content);
// 向 client 端发送响应数据
}
//关闭各个流
// out.flush(); 清缓冲区

out.close();
in.close();
// 一次通讯结束,可以关闭socket
this.sk.close();
} catch (Exception ex) {
// ex.printStackTrace();
System.out.println("客户挂断了.........");
}

}
}

// 在客户端部署的程序

package wang.socket.Client;

import java.net.*;
import java.io.*;

/**
*
* @author WangQingda
*/
public class AWTClient extends javax.swing.JFrame {

/** Creates new form AWTClient */
public AWTClient() {

initComponents();
}

/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {

jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
theServerIP = new javax.swing.JTextField();
jScrollPane1 = new javax.swing.JScrollPane();
theContent = new javax.swing.JTextArea();
jButton1 = new javax.swing.JButton();
jScrollPane2 = new javax.swing.JScrollPane();
theServerOutPut = new javax.swing.JTextArea();

setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("测试Socket数据流");

jLabel1.setText("请输入服务器地址：");

jLabel2.setText("输入需要提交数据流：");

theServerIP.setText("127.0.0.1");

theContent.setColumns(20);
theContent.setRows(5);
jScrollPane1.setViewportView(theContent);

jButton1.setLabel("提交");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});

theServerOutPut.setColumns(20);
theServerOutPut.setRows(5);
jScrollPane2.setViewportView(theServerOutPut);

javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
.addContainerGap()
.addComponent(jScrollPane2))
.addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()
.addGap(31, 31, 31)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel2)
.addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 88, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 317, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel1)
.addGap(18, 18, 18)
.addComponent(theServerIP, javax.swing.GroupLayout.PREFERRED_SIZE, 167, javax.swing.GroupLayout.PREFERRED_SIZE)))))
.addContainerGap(31, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(41, 41, 41)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel1)
.addComponent(theServerIP, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addGroup(layout.createSequentialGroup()
.addGap(34, 34, 34)
.addComponent(jLabel2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jButton1))
.addGroup(layout.createSequentialGroup()
.addGap(18, 18, 18)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(13, Short.MAX_VALUE))
);

pack();
}// </editor-fold>

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
try {
//连接 server 端
System.out.println("连接服务器 ...");
Socket client = new Socket(this.theServerIP.getText(), 9999);

//显示已连接
System.out.println("成功接入服务器.");
System.out.println();

//为发送数据做准备
System.out.println("请输入:");
// 注意字符串要以字符流的形式读入。
BufferedReader in = new BufferedReader(new StringReader(this.theContent.getText()));
// 流的输出可以从socket的输出流得到。
PrintWriter out = new PrintWriter(client.getOutputStream(), true);

// 向 server 发送数据
String outTxt;
while ((outTxt = in.readLine()) != null) {
out.println(outTxt);
System.out.println("向服务器发送:"+outTxt);

}
out.flush();
this.theServerOutPut.append("数据已经成功向服务器发送");
//接收来自 server 的响应数据
in = new BufferedReader(new InputStreamReader(client.getInputStream()));
String inTxt;
while ((inTxt = in.readLine()) != null) {
this.theServerOutPut.append(inTxt);

}
// 关闭各个流
in.close();
out.close();
// 客户端退出
client.close();

} catch (Exception e) {
e.printStackTrace();
}
}

/**
* @param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {

public void run() {
new AWTClient().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JScrollPane jScrollPane2;
private javax.swing.JTextArea theContent;
private javax.swing.JTextField theServerIP;
private javax.swing.JTextArea theServerOutPut;
// End of variables declaration
}