问了几天，看了些别人的程序，修改了还是不行！！真的没人指教一下吗:c ?

Question

客户端代码

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.ScrollPaneConstants;


public class chat {

    JFrame frame;
    JTextArea outputText;
    JTextField inputText;
    JButton sendButton;
    JPanel mainPanel;
    JPanel inputPanel;
    BufferedReader reader;
    Socket socket;
    PrintWriter writer;
    public static void main(String[] args) {

        chat chat=new chat();
        chat.setUpNetWorking();
        chat.buildGUI();

    }

    public void setUpNetWorking() {
        try {
            socket=new Socket("127.0.0.1",5000);

            reader=new BufferedReader(new InputStreamReader(socket.getInputStream()));

            writer=new PrintWriter(socket.getOutputStream());
        }catch (IOException e) {
            e.printStackTrace();
        }


    }

    public void buildGUI(){

        outputText=new JTextArea("",8,20);
        outputText.setLineWrap(true);
        outputText.setEditable(false);
        JScrollPane scroller=new JScrollPane(outputText);
        scroller.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
        scroller.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);


        inputText=new JTextField(15);
        inputText.addActionListener(new SendListener());
        sendButton=new JButton("send");
        inputPanel=new JPanel();
        inputPanel.setLayout(new BorderLayout());
        inputPanel.add(inputText,BorderLayout.CENTER);
        inputPanel.add(sendButton,BorderLayout.EAST);

        frame=new JFrame("Chat Windows");
        frame.getContentPane().add(scroller,BorderLayout.CENTER);
        frame.getContentPane().add(inputPanel,BorderLayout.SOUTH);
        frame.setVisible(true);
        frame.pack();
        inputText.requestFocus();
    }
    public class SendListener implements ActionListener{



        @Override
        public void actionPerformed(ActionEvent e) {

            outputText.setText(outputText.getText()+"me :"+inputText.getText()+"\n");
            writer.println(inputText.getText());
            writer.flush();
            System.out.println("client send it "+inputText.getText());
            inputText.setText("");
            inputText.requestFocus();
        }

        public class ReceiveRunnable implements Runnable {

            @Override
            public void run() {
                while(true){
                String message=null;
                try {
                    while((message=reader.readLine())!=null){
                        System.out.println("cilent Revive it "+message);
                        outputText.setText(outputText.getText()+"someone:"+message+"\n");
                    }
                } catch (IOException e) {
                    // TODO 自动生成的 catch 块
                    e.printStackTrace();
                }
            }
            }

        }
    }

}

服务器代码

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Iterator;


public class ChatServer {
    ArrayList<PrintWriter> inputStramList=new ArrayList<PrintWriter>();

    public static void main(String[] args) {
        ChatServer server=new ChatServer();
        server.go();

    }
    public void go(){
         try {
            ServerSocket serverSocket=new ServerSocket(5000);

            while(true){
                Socket clientSocket=serverSocket.accept();
                System.out.println("server connected it");
                PrintWriter writer=new PrintWriter(clientSocket.getOutputStream());
                inputStramList.add(writer);

                Thread t=new Thread(new ReceiveRunnable(clientSocket));
                t.start();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public class ReceiveRunnable implements Runnable {
        BufferedReader reader;

        public ReceiveRunnable(Socket socket){
            try {
                reader=new BufferedReader(new InputStreamReader(socket.getInputStream()));

            } catch (IOException e) {

            }
        }
        public void run() {
            String message;
            while(true){ 
            try { 
                while((message=reader.readLine())!=null){
                    telleverbody(message);
                    System.out.println("server send it "+message);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            }
        }
        private void telleverbody(String message) {
            Iterator<PrintWriter> it=inputStramList.iterator();
            while(it.hasNext()){
                PrintWriter writer=(PrintWriter) it.next();
                writer.println(message);
                writer.flush();
            }

        }

    }
}

Answer 1

 import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.Iterator;


public class ChatServer {
    ArrayList<PrintWriter> inputStramList=new ArrayList<PrintWriter>();

    public static void main(String[] args) {
        ChatServer server=new ChatServer();
        server.go();

    }
    public void go(){
         try {
            ServerSocket serverSocket=new ServerSocket(5000);

            while(true){
                Socket clientSocket=serverSocket.accept();
                System.out.println("server connected it");
                PrintWriter writer=new PrintWriter(clientSocket.getOutputStream());
                inputStramList.add(writer);


                Thread t=new Thread(new ReceiveRunnable(clientSocket));
                t.start();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public class ReceiveRunnable implements Runnable {
        BufferedReader reader;

        public ReceiveRunnable(Socket socket){
            try {
                reader=new BufferedReader(new InputStreamReader(socket.getInputStream()));

            } catch (IOException e) {

            }
        }
        public void run() {
            String message;
            while(true){ 
            try { 
                //  同客户端
                if((message=reader.readLine())!=null){
                    telleverbody(message);
                    System.out.println("server send it "+message);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            }
        }
        private void telleverbody(String message) {
            Iterator<PrintWriter> it=inputStramList.iterator();
            while(it.hasNext()){
                // 本来Iterator就有泛型，不需要强制类型转换
                PrintWriter writer= it.next();
                writer.println(message);
                writer.flush();
            }

        }

    }
}

 import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.ScrollPaneConstants;

public class chat {

    JFrame frame;
    JTextArea outputText;
    JTextField inputText;
    JButton sendButton;
    JPanel mainPanel;
    JPanel inputPanel;
    BufferedReader reader;
    Socket socket;
    PrintWriter writer;
    //定义一个昵称用于表示消息的发送者
    private String nickName;

    public static void main(String[] args) {

        chat chat = new chat();
        chat.setUpNetWorking();
        chat.buildGUI();

    }

    public void setUpNetWorking() {
        try {
            socket = new Socket("127.0.0.1", 5000);

            reader = new BufferedReader(new InputStreamReader(socket
                    .getInputStream()));

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

            //线程应该在此处开启
            // 用于监听服务器消息
            ReceiveRunnable run = new ReceiveRunnable();
            Thread t = new Thread(run);
            t.start();


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

    }

    public void buildGUI() {
        //初始化昵称
        while(nickName==null || "".equals(nickName.trim()))
        {
            nickName = JOptionPane.showInputDialog(frame, "请输入昵称");
        }
        frame.setTitle(nickName + "的聊天室");

        outputText = new JTextArea("", 8, 20);
        outputText.setLineWrap(true);
        outputText.setEditable(false);
        JScrollPane scroller = new JScrollPane(outputText);
        scroller
                .setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
        scroller
                .setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);

        inputText = new JTextField(15);
//      inputText.addActionListener(new SendListener());
        // 发送事件应该加在button上 而不是JTextField上
        sendButton = new JButton("send");
        sendButton.addActionListener(new SendListener());
        inputPanel = new JPanel();
        inputPanel.setLayout(new BorderLayout());
        inputPanel.add(inputText, BorderLayout.CENTER);
        inputPanel.add(sendButton, BorderLayout.EAST);

        frame = new JFrame("Chat Windows");
        frame.getContentPane().add(scroller, BorderLayout.CENTER);
        frame.getContentPane().add(inputPanel, BorderLayout.SOUTH);
        frame.setVisible(true);
        frame.pack();
        inputText.requestFocus();
    }

    public class SendListener implements ActionListener {



        @Override
        public void actionPerformed(ActionEvent e) {

            //服务器是将数据写回到所有客户端，所以不需要在自己的消息区拼接消息
//          outputText.setText(outputText.getText() + "me :"
//                  + inputText.getText() + "\n");
            String msg = nickName + ":" + inputText.getText();
            writer.println(msg);
            writer.flush();
            System.out.println("client send it " + inputText.getText());
            inputText.setText("");
            inputText.requestFocus();
        }


    }

    public class ReceiveRunnable implements Runnable {

        @Override
        public void run() {
            while (true) {
                String message = null;
                try {
                    //不应该是while循环，外面已经有while了 if就够了
                    //其实if都不需要，因为reader.readLine()会阻塞线程
                    if ((message = reader.readLine()) != null) {
                        System.out.println("cilent Revive it " + message);
                        // 发送时已经加过昵称，所以不需要someone
                        outputText.setText(outputText.getText()
                                 + message + "\n");
                    }
                } catch (IOException e) {
                    // TODO 自动生成的 catch 块
                    e.printStackTrace();
                }
            }
        }

    }

}