java中Socket通信

Posted 2023-04-23

请问如何Client-A向Server发送信息,Server将信息发给Client-B?请贴出代码,我加高分,谢谢
2楼的程序执行applet登陆的时候会报连接异常

你加了高分我才贴
----------------具体是： Client-A发送消息向Server:消息包括内容+流向(Client-B的地址)+消息来源地址 Server接收后再把消息+来源地址发给Client-B 参考技术A 两个文件都给你
肯定没有错的

//ChatServer.java

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

public class ChatServer
boolean started = false;
ServerSocket ss = null;

List<Client> clients = new ArrayList<Client>();

public static void main(String[] args)
new ChatServer().start();


public void start()
try
ss = new ServerSocket(8888);
started = true;
catch (BindException e)
System.out.println("端口使用中....");
System.out.println("请关掉相关程序并重新运行服务器！");
System.exit(0);
catch (IOException e)
e.printStackTrace();


try

while(started)
Socket s = ss.accept();
Client c = new Client(s);
System.out.println("a client connected!");
new Thread(c).start();
clients.add(c);
//dis.close();

catch (IOException e)
e.printStackTrace();
finally
try
ss.close();
catch (IOException e)
// TODO Auto-generated catch block
e.printStackTrace();




class Client implements Runnable
private Socket s;
private DataInputStream dis = null;
private DataOutputStream dos = null;
private boolean bConnected = false;

public Client(Socket s)
this.s = s;
try
dis = new DataInputStream(s.getInputStream());
dos = new DataOutputStream(s.getOutputStream());
bConnected = true;
catch (IOException e)
e.printStackTrace();



public void send(String str)
try
dos.writeUTF(str);
catch (IOException e)
clients.remove(this);
System.out.println("对方退出了！我从List里面去掉了！");
//e.printStackTrace();



public void run()
try
while(bConnected)
String str = dis.readUTF();
System.out.println(str);
for(int i=0; i<clients.size(); i++)
Client c = clients.get(i);
c.send(str);
//System.out.println(" a string send !");

/*
for(Iterator<Client> it = clients.iterator(); it.hasNext(); )
Client c = it.next();
c.send(str);

*/
/*
Iterator<Client> it = clients.iterator();
while(it.hasNext())
Client c = it.next();
c.send(str);

*/

catch (EOFException e)
System.out.println("Client closed!");
catch (IOException e)
e.printStackTrace();
finally
try
if(dis != null) dis.close();
if(dos != null) dos.close();
if(s != null)
s.close();
//s = null;


catch (IOException e1)
e1.printStackTrace();








//ChatClient.java

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;

public class ChatClient extends Frame
Socket s = null;
DataOutputStream dos = null;
DataInputStream dis = null;
private boolean bConnected = false;

TextField tfTxt = new TextField();

TextArea taContent = new TextArea();

Thread tRecv = new Thread(new RecvThread());

public static void main(String[] args)
new ChatClient().launchFrame();


public void launchFrame()
setLocation(400, 300);
this.setSize(300, 300);
add(tfTxt, BorderLayout.SOUTH);
add(taContent, BorderLayout.NORTH);
pack();
this.addWindowListener(new WindowAdapter()

@Override
public void windowClosing(WindowEvent arg0)
disconnect();
System.exit(0);


);
tfTxt.addActionListener(new TFListener());
setVisible(true);
connect();

tRecv.start();


public void connect()
try
s = new Socket("127.0.0.1", 8888);
dos = new DataOutputStream(s.getOutputStream());
dis = new DataInputStream(s.getInputStream());
System.out.println("connected!");
bConnected = true;
catch (UnknownHostException e)
e.printStackTrace();
catch (IOException e)
e.printStackTrace();




public void disconnect()
try
dos.close();
dis.close();
s.close();
catch (IOException e)
e.printStackTrace();


/*
try
bConnected = false;
tRecv.join();
catch(InterruptedException e)
e.printStackTrace();
finally
try
dos.close();
dis.close();
s.close();
catch (IOException e)
e.printStackTrace();


*/


private class TFListener implements ActionListener

public void actionPerformed(ActionEvent e)
String str = tfTxt.getText().trim();
//taContent.setText(str);
tfTxt.setText("");

try
//System.out.println(s);
dos.writeUTF(str);
dos.flush();
//dos.close();
catch (IOException e1)
e1.printStackTrace();






private class RecvThread implements Runnable

public void run()
try
while(bConnected)
String str = dis.readUTF();
//System.out.println(str);
taContent.setText(taContent.getText() + str + '\n');

catch (SocketException e)
System.out.println("退出了，bye!");
catch (EOFException e)
System.out.println("推出了，bye - bye!");
catch (IOException e)
e.printStackTrace();





参考技术B 看看这个怎么样：
import java.io.*;
import java.net.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import ccit.Message;

public class Server extends Thread

public static final int PORT = 1112;
Socket socket;
ServerSocket serverSocket;

static Vector usrList=new Vector(1,1);

public Server()

try

serverSocket=new ServerSocket(PORT);

catch(IOException ioe)

System.out.println("Can't set up server socket."+ioe);

System.out.println("server start ...");
this.start();

public void run()

try

while (true)

System.out.println("正在等待连接.....");
socket = serverSocket.accept();
//PrintWriter pw=new PrintWriter(socket.getOutputStream());
// pw.println("aaa");
usrThread ut=new usrThread(socket);
usrList.addElement(ut);


catch(IOException ioe1)

System.out.println("Can't set up user thread"+ioe1);



public static void main(String args[])

Server sobj=new Server();




class usrThread extends Thread

Socket socket;
ObjectInputStream osFromClient;
ObjectOutputStream osToClient;

thPut tp;
thGet tg;

static int msgCount=0;
static Vector msgBox = new Vector(1,1);

int localCount=0;

public synchronized void writeMsg(Message msg)

msgBox.addElement(msg);
msgCount++;


public synchronized Message readMsg()

Message msg=(Message)(msgBox.elementAt(localCount));
return msg;


public usrThread(Socket s)

socket=s;
try

osFromClient=new ObjectInputStream(socket.getInputStream());
osToClient=new ObjectOutputStream(socket.getOutputStream());
System.out.println("osToClient and osFromClient finished!");

this.start();
tp=new thPut();
tp.start();
tg=new thGet();
tg.start();

catch(Exception e)

System.out.println("usrThread init error! "+e);




public void run()



class thPut extends Thread

Message msg;

public void run()

try

while(true)

msg = (Message)osFromClient.readObject();
writeMsg(msg);
System.out.println(msg.fromname+" says: "+msg.message);


catch(Exception e)

System.out.println("Receive error"+e);





class thGet extends Thread

//Declare the currnet message get from readMsg method
Message msg=new Message();
public void run()

try

while(true)


while (localCount>=msgCount)

this.sleep(1);

msg=readMsg();
System.out.println("Write to "+msg.toname);
osToClient.writeObject(msg);

System.out.println(String.valueOf(localCount));
localCount++;



catch(Exception e)

System.out.println("cant write msg to client"+e);







客户端代码：
import java.io.*;
import java.net.*;
import java.util.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import ccit.Message;

public class ClientChat extends JFrame


static long sum;
JLabel lpublic=new JLabel("公共聊天区");
JLabel lprivate=new JLabel("私人聊天区");
JLabel lgetlist=new JLabel("在线用户");

JTextArea taPublicMsg=new JTextArea(10,15);
JTextArea taPrivateMsg=new JTextArea(6,10);

JTextField tfSendMsg=new JTextField(40);

JButton bsend=new JButton("发送");
JButton bexit=new JButton("退出");

JPanel pLabelPub=new JPanel();
JPanel pLabelPri=new JPanel();

Vector userVector=new Vector(1,1);

JList userList=new JList();

Socket socket=null;

String name;

ObjectOutputStream oos=null;
ObjectInputStream ois=null;

public ClientChat(String name)


JScrollPane scrpPub=new JScrollPane(taPublicMsg);
pLabelPub.setLayout(new BorderLayout());
pLabelPub.add(lpublic,BorderLayout.NORTH);
pLabelPub.add(scrpPub,BorderLayout.CENTER);

JScrollPane scrpPri=new JScrollPane(taPrivateMsg);
pLabelPri.setLayout(new BorderLayout());
pLabelPri.add(lprivate,BorderLayout.NORTH);
pLabelPri.add(scrpPri,BorderLayout.CENTER);

JPanel pGetMsg=new JPanel();
pGetMsg.setLayout(new GridLayout(3,1,5,5));
pGetMsg.add(pLabelPub);
//pGetMsg.add(taPublicMsg);
pGetMsg.add(pLabelPri);
//pGetMsg.add(taPrivateMsg);

JPanel pSendMsg=new JPanel();
pSendMsg.setLayout(new FlowLayout());
pSendMsg.add(tfSendMsg);
pSendMsg.add(bsend);
pSendMsg.add(bexit);

pGetMsg.add(pSendMsg);

userVector.addElement("To All");
userList.setListData(userVector);
JScrollPane scrpList=new JScrollPane(userList);

JPanel pGetList=new JPanel();
pGetList.setLayout(new BorderLayout());
pGetList.add(lgetlist,BorderLayout.NORTH);
pGetList.add(scrpList,BorderLayout.CENTER);

this.getContentPane().setLayout(new BorderLayout());
this.getContentPane().add(pGetMsg,BorderLayout.CENTER);
this.getContentPane().add(pGetList,BorderLayout.EAST);
this.setTitle("小桥流水(花语)聊天室(在线用户"+(++sum)+"位)");
this.setSize(500,300);
this.setVisible(true);

this.name=name;
//this.socket=socket;

try

System.out.println("正在连接.....");
InetAddress addr = InetAddress.getByName(null);
System.out.println("addr = " + addr);

//socket = new Socket(addr,Server.PORT);
//socket = new Socket("127.0.0.1",1112);

ois=new ObjectInputStream(socket.getInputStream());
oos=new ObjectOutputStream(socket.getOutputStream());

//PrintWriter pw=new PrintWriter(oos);

Message msgLogin=new Message("To All",name,"Login","Login");

//pw.print(msgLogin);
oos.writeObject(msgLogin);
new manageThread().start();


catch(Exception e)

System.out.println("JFtame error:"+e);



public class sendListener implements ActionListener

public void actionPerformed(ActionEvent evt)

Message getMsg=new Message();
getMsg.toname=userList.getSelectedValue().toString();
getMsg.fromname=name;
getMsg.message=tfSendMsg.getText();
getMsg.command="chat";
try

oos.writeObject(getMsg);

catch(Exception e)

System.out.println("Send:"+getMsg.message);




public class exitListener implements ActionListener

public void actionPerformed(ActionEvent evt)

Message getMsg=new Message("To All",name,"","Logout");
try

oos.writeObject(getMsg);

catch(Exception e)

System.out.println(e);

ClientChat.this.setVisible(false);



public class manageThread extends Thread

Message GetMessage;
public void run()

while(true)

try

GetMessage=(Message)ois.readObject();
if(GetMessage.command.equals("Login"))

userVector.addElement(GetMessage.fromname);
userList.setListData(userVector);
taPublicMsg.append(GetMessage.fromname+"has arrived!\n");


if(GetMessage.command.equals("Logout"))

int i=0;
for(i=0;i<userVector.size();i++)

if(((String)userVector.elementAt(i)).equals(GetMessage.fromname))

System.out.println("i="+i);
break;


if(i<userVector.size())

userVector.removeElementAt(i);
userList.updateUI();

taPublicMsg.append(GetMessage.fromname+"has left!\n");


if(GetMessage.command.equals("chat"))

if(GetMessage.toname.equals(name))

taPrivateMsg.append(GetMessage.fromname+"say to me:"+GetMessage.message+"\n");

else

taPublicMsg.append(GetMessage.fromname+"say to all:"+GetMessage.message+"\n");



catch(Exception e)

System.out.println("GetMessage error:"+e);
break;






/* public static void main(String args[])

Socket socket=null;
new ClientChat(socket,"all");
*/



import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.net.*;
import ccit.Message;
public class ClientLogin extends JApplet

JLabel lname=new JLabel("用户名：");
JLabel lpasswd=new JLabel("密 码：");
JTextField tname=new JTextField(10);
JTextField tpasswd=new JTextField(10);
JButton blogin=new JButton("登录");
//Socket socket=null;
public void init()

JPanel pup=new JPanel();
JPanel pdown=new JPanel();

pup.setLayout(new GridLayout(2,2,5,5));
pup.add(lname);
pup.add(tname);
pup.add(lpasswd);
pup.add(tpasswd);

pdown.setLayout(new FlowLayout());
pdown.add(blogin);

blogin.addActionListener(new loginListener());

this.getContentPane().setLayout(new BorderLayout());
this.getContentPane().add(pup,BorderLayout.CENTER);
this.getContentPane().add(pdown,BorderLayout.SOUTH);


public class loginListener implements ActionListener

public void actionPerformed(ActionEvent evt)

if(evt.getSource()==blogin)

try

//Socket socket=new Socket(InetAddress.getLocalHost(),7000);
Socket socket=new Socket("127.0.0.1",1112);
ClientChat customer=new ClientChat(tname.getText());

catch(Exception e)

System.out.println("Client error:"+e);
return;






package ccit;
import java.io.*;
public class Message implements Serializable

public String toname;
public String fromname;
public String message;
public String command;

public Message()



public Message(String to,String from,String msg,String command)

this.toname=to;
this.fromname=from;
this.message=msg;
this.command=command;




客户端要在Applet运行的。

Java中Socket 实现最简单的客户端与服务端通信

Java中Socket 实现最简单的客户端与服务端通信

引言：因为最近项目中要接入某通信协议接口，基于TCP/IP的socket接口。于是就在本地弄一个最简单的Socket 通信仅供学习。话不多说，直接开摆

客户端代码

package test;

import java.io.*;
import java.net.Inet4Address;
import java.net.InetSocketAddress;
import java.net.Socket;
public class Client 
    //java基础类方法的入口
    public static void main(String[] args)throws IOException 
        Socket socket=new Socket();
        //读取流超时的时间设置为3000
        socket.setSoTimeout(3000);
        //连接本地，端口2000；超时时间3000ms
        socket.connect(new InetSocketAddress(Inet4Address.getLocalHost(), 2000),3000);
        System.out.println("发起服务器连接---------");
        System.out.println("客户端信息："+socket.getLocalAddress()+" P:"+socket.getLocalPort());//打印本地服务器地址和本地端口号
        System.out.println("服务端信息："+socket.getInetAddress()+" P:"+socket.getPort());
        try
            //发送接收数据
            todo(socket);
        catch (Exception e)
            System.out.println("出现异常关闭啦");
        
        //释放资源
        socket.close();
        System.out.println("再见，客户端已退出");
    
    //发送数据的方法
    private  static void todo(Socket client) throws IOException
        //构建键盘输入流
        InputStream in=System.in;
        //把键盘输入流转换为BufferedReader
        BufferedReader input=new BufferedReader(new InputStreamReader(in,"UTF-8"));
        //得到Socket输出流（Client要发送出去给服务器的信息），并转换为打印流
        OutputStream outputStream = client.getOutputStream();
        PrintStream socketPrintStream=new PrintStream(outputStream);
        //得到Socket输入流（Server回复传入Client的信息）,并转换为BufferedReader
        InputStream inputStream = client.getInputStream();
        BufferedReader socketBufferedReader=new BufferedReader(new InputStreamReader(inputStream,"UTF-8"));
        //判断Server是否想要退出，回复“bye”时是他想要结束对话
        boolean flag=true;
        do 
            //键盘读取一行
            String str = input.readLine();
            //发送到服务器，（通俗就是显示在输入处，在键盘上输入什么，屏幕显示什么）
            //String str = "003099999920220614100000M1S1C0x0a";
            socketPrintStream.println(str);
            //从服务器读取一行，即Server传入回复给Client的信息
            String echo = socketBufferedReader.readLine();
            if("bye".equalsIgnoreCase(echo))
                flag=false;
             else
                //打印到屏幕上，Server回复什么就显示什么
                System.out.println("客户端回复："+echo);
            
        while(flag);
        //资源释放，关闭对于socket资源
        socketPrintStream.close();
        socketBufferedReader.close();
    

 

服务端代码

package test;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
public class Server 
    public static void main(String[] args)throws IOException 
        ServerSocket server=new ServerSocket(2000);
        System.out.println("服务器准备就绪----------");
        System.out.println("服务器信息："+server.getInetAddress()+" P:"+server.getLocalPort());
        //等待多个客户端连接，循环异步线程
        for(;;) 
            //得到客户端
            Socket client = server.accept();
            //客户端构建异步线程
            ClientHandler clientHandler = new ClientHandler(client);
            //启动线程
            clientHandler.start();
        
    
    /**
     * 客户端消息处理
     */
    //多个客户端需要做异步操作，建立异步处理类
    private static class ClientHandler extends Thread//线程
        private  Socket socket;//代表当前的一个连接
        private boolean flag=true;
        ClientHandler(Socket socket)
            this.socket=socket;
        //构造方法
        //一旦Thead启动起来，就会运行run方法，代表线程启动的部分
        @Override
        public void run()
            super.run();
            //打印客户端的信息
            System.out.println("新客户端发起连接："+socket.getInetAddress()+" P:"+socket.getPort());
            //在发送过程中会触发一个IO过程，所以需要捕获异常
            try 
                //得到打印流，用于数据输出，服务器回送数据使用，即在屏幕上显示Server要回复Client的信息
                PrintStream socketOutput=new PrintStream(socket.getOutputStream());
                //得到输入流，用于接收数据，得到Client回复服务器的信息
                BufferedReader sockeInput=new BufferedReader(new InputStreamReader(socket.getInputStream(),"UTF-8"));
                do 
                    //客户端回复一条数据
                    String str = sockeInput.readLine();
                    if("bye".equalsIgnoreCase(str))
                        flag=false;
                        //回送
                        socketOutput.println("bye");
                    else
                        //打印到屏幕，并回送数据长度
                        System.out.println(str);
                        socketOutput.println("Server回答说：" +str.length());
                    
                while(flag);
                sockeInput.close();
                socketOutput.close();
            catch (Exception e)
                //触发异常时打印一个异常信息
                System.out.println("连接异常断开！！！");
            finally 
                //连接关闭
                try 
                    socket.close();
                 catch (IOException e) 
                    e.printStackTrace();
                
            
            System.out.println("再见，客户端退出："+socket.getInetAddress()+" P:"+socket.getPort());
        
    

 

 

然后先运行服务端类Server.java,然后再运行Client.java
在客户端控制台输入任意文字，按下回车键即可。

 

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