Java简单的客户端与服务器的建立与通信

简述：

建立简单的server与client，在利用socket上通信

知识点：

1. java socket 通信

2. java GUI的几个控件

3. 多线程并发

代码：

SimpleChatServer.java

package test.chatclient;

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

public class SimpleChatServer {
ArrayList<PrintWriter> clientOutputStreams;
public static void main(String[] args){
new SimpleChatServer().go();
}

public class ClientHandler implements Runnable{
BufferedReader reader;
Socket sock;
public ClientHandler(Socket clientSocket){
try{
sock = clientSocket;
InputStreamReader isReader = new InputStreamReader(sock.getInputStream());
reader = new BufferedReader(isReader);
}catch(Exception ex){
ex.printStackTrace();
}
}
@Override
public void run() {
String message;
try{
while((message = reader.readLine()) != null){
System.out.println("read " + message);
tellEveryone(message);
}
}catch(Exception ex){
ex.printStackTrace();
}
}
}

public void tellEveryone(String message){
Iterator<PrintWriter> it = clientOutputStreams.iterator();
while(it.hasNext()){
try{
PrintWriter writer = (PrintWriter)it.next();
writer.println(message);
writer.flush();
}catch(Exception ex){
ex.printStackTrace();
}
}
}

public void go(){
clientOutputStreams = new ArrayList<PrintWriter>();
try{
ServerSocket serverSock = new ServerSocket(5000);
while(true){
Socket clientSocket = serverSock.accept();
PrintWriter writer = new PrintWriter(clientSocket.getOutputStream());
clientOutputStreams.add(writer);
Thread t = new Thread(new ClientHandler(clientSocket));
t.start();
System.out.println("got a connection");
}
}catch(Exception ex){
ex.printStackTrace();
}
}
}

SimpleChatClient.java

package test.chatclient;
import java.io.*;
import java.net.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.JOptionPane;

public class SimpleChatClient {
JTextArea incoming;
JTextField outgoing;
BufferedReader reader;
PrintWriter writer;
Socket sock;
static String clientName;

public static void main(String[] args) {
SimpleChatClient client = new SimpleChatClient();
clientName = JOptionPane.showInputDialog("Please input the client name :");
client.go();
}

public void go() {
// build GUI
JFrame frame = new JFrame(clientName + "'s Chat Client");
JPanel mainPanel = new JPanel();
incoming = new JTextArea(15,20);
incoming.setLineWrap(true);
incoming.setWrapStyleWord(true);
incoming.setEditable(false);

JScrollPane qScroller = new JScrollPane(incoming);
qScroller.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
qScroller.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);

outgoing = new JTextField(20);

JButton sendButton = new JButton("Send");
sendButton.addActionListener(new SendButtonListener());

mainPanel.add(qScroller);
mainPanel.add(outgoing);
mainPanel.add(sendButton);

setUpNetworking();
Thread readerThread = new Thread(new IncomingReader());
readerThread.start();

frame.getContentPane().add(BorderLayout.CENTER, mainPanel);
frame.setSize(400,500);
frame.setVisible(true);

} // close go

private void setUpNetworking() {
try {
sock = new Socket("127.0.0.1", 5000);
InputStreamReader streamReader = new InputStreamReader(sock.getInputStream());
reader = new BufferedReader(streamReader);

writer = new PrintWriter(sock.getOutputStream());

System.out.println("networking established");
} catch(IOException ex) {
ex.printStackTrace();
}
} // close setUpNetworking

public class SendButtonListener implements ActionListener {
public void actionPerformed(ActionEvent ev) {
try {
writer.println(clientName+" says:\n"+outgoing.getText());
writer.flush();
} catch(Exception ex) {
ex.printStackTrace();
}
outgoing.setText("");
outgoing.requestFocus();
}
}  // close SendButtonListener inner class

public class IncomingReader implements Runnable {
public void run() {
String message = null;
try {
while ((message = reader.readLine()) != null) {
System.out.println("read " + message);
incoming.append(message + "\n");
} // close while
} catch(Exception ex) {ex.printStackTrace();}
} // close run
} // close inner class
}

输出：