java实现简易的局域网对话系统

先说一下

1. 写的确实比较一般，别喷
2. 为什么呢，疫情原因，学校提前两周期末考试，时间也不太充足，将就一下

服务器代码：

package xcvcvcx;


import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Map;

public class Server {
  static int index = 0;
  static BufferedWriter[] userWrite = new BufferedWriter[100];
  static BufferedReader[] userRead = new BufferedReader[100];
  static Socket[] userSocket = new Socket[100];
  static String[] userId = new String[100];
  static String[] userName = new String[100];


  public static void main(String[] args) throws IOException {
    ServerSocket ss = new ServerSocket(6666); // 监听指定端口
    System.out.println("server is running...");
    index = 0;
    for (;;) {
      Socket sock = ss.accept();
      String idd = sock.getRemoteSocketAddress().toString();
      System.out.println("connected from " + sock.getRemoteSocketAddress());
      userSocket[index] = sock;

      Thread t = new Handler(sock);
      ((Handler) t).userId = idd;
      userId[index]=((Handler) t).userId =idd;
      t.start();
    }
  }
}

class Handler extends Thread {
  Socket sock;
  BufferedWriter writer;
  BufferedReader reader;
  String username;
  String userId;


  public Handler(Socket sock) {
    this.sock = sock;
  }

  public void synMessage(Map<String,String> message) throws IOException {
    BufferedWriter writer;
    BufferedWriter[] user =Server.userWrite;
    int isall =1;
    String dis = "a";
    if ( message.get("messageclass").toString().equals("normally")  ){
      dis = message.get("distination");
      System.out.println(dis);
      System.out.println();
      if (dis.equals("all") == false){
        System.out.println("no isall");
        isall= 0;
      }
    }
    int len = Server.index;
    for(int i =0; i< len;i++)
    {
      if (Server.userWrite[i] == null){
        continue;
      }
      System.out.println("vf");
      if (isall == 0){
        // 专门的消息
        if (Server.userName[i].equals(dis)){
          message.put( "distinationId",Server.userId[i] );
          writer = user[i];
          writer.write(message.toString() + "\n");
          System.out.print("专门消息发送成功");
          writer.flush();
          return;
        }
        continue;

      }
      message.put( "distinationId",Server.userId[i] );
      if (Server.userWrite[i] == null){
        continue;
      }
      if ( Server.userId[i].equals(this.userId) == false)
      {
        writer = user[i];
        writer.write(message.toString() + "\n");
        System.out.print("进来了");
        writer.flush();
      }else {
        writer = user[i];
        writer.write(message.toString() + "\n");
        System.out.print("进来了");
        writer.flush();
      }

    }
  }

  public  void synUserList(Map<String,String> message,String Id){
    BufferedWriter writer;
    BufferedWriter[] user =Server.userWrite;
    // 封装 用户列表
    // 规定用户名不可以有空格

    int len = Server.index;
    String userLis = "here";
    for (int i = 0; i< len ; i++)
    {
      System.out.println(userLis);
      if (Server.userWrite[i]!=null){
        if (message.get("userId").equals(Server.userId[i])){
          continue;
        }else {
          if (Server.userName[i] ==null){
            continue;
          }
          userLis = userLis + " " + Server.userName[i];
        }
      }
    }
    message.put( "distinationId",Id);
    message.put( "userList",userLis);
    message.put("messageclass","synUserList");

    for(int i =0; i< len;i++)
    {
      if (Server.userWrite[i] == null){
        continue;
      }
      if ( Server.userId[i].equals(Id))
      {
        writer = user[i];
        try {
          writer.write(message.toString() + "\n");
          writer.flush();
          return;
        } catch (IOException e) {
          e.printStackTrace();
        }
      }

    }


  }

  @Override
  public void run() {
    try (InputStream input = this.sock.getInputStream()) {
      try (OutputStream output = this.sock.getOutputStream()) {

        handle(input, output);
      }
    } catch (Exception e) {
      try {
        this.sock.close();
      } catch (IOException ioe) {
      }
      System.out.println("client disconnected.");
    }
  }



  private void handle(InputStream input, OutputStream output) throws IOException {
    BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(output, StandardCharsets.UTF_8));
    BufferedReader reader = new BufferedReader(new InputStreamReader(input, StandardCharsets.UTF_8));
    this.writer = writer;
    this.reader = reader;
    int inde = Server.index;
    Server.index++;
    Server.userRead[inde] = reader;
    Server.userWrite[inde] = writer;
    Map<String,String> message=  new HashMap<String, String>();
    message.put("messageclass", "synId");// 普通 消息
    message.put( "userId",userId );
    message.put( "userIndex",String.valueOf(inde) );
    String  to=message.toString();
    writer.write(to+'\n');
    writer.flush();
    for (;;) {
      String s = reader.readLine();

      if (s == null){
        continue;
      }
//      System.out.print(s);
//      synMessages(s);
      Map<String, String> mess= Client.mapStringToMap(s);
////      System.out.print(s);
      if(mess.get("messageclass").toString().equals("normally"))
      {
        System.out.print("irieowmxn");
        synMessage(mess);
        continue;

      }else  if (mess.get("messageclass").toString().equals("synUserName")){
        System.out.println("now synuser");
        String id = mess.get("userId");
        System.out.println(mess.toString());
        username = mess.get("user");
        int index = Integer.parseInt( mess.get("userIndex") );
        Server.userName[index] = username;
        // 同步 在线用户
        Map<String,String> synuser=  new HashMap<String, String>();
        synuser.put("messageclass", "addUser");// 普通 消息
        synuser.put( "userName",username );
        synMessage(synuser);

        // 同步所以已在线用户， 有新用户 登录
        // 其实  我们还需要   回复 该用户，  现在有哪些在线    以便于  后来登录的人   用户列表  无法更新
        synUserList(message,id);
        continue;

      }else if ( mess.get("messageclass").toString().equals("userClose") ){
        Map<String,String> synuser=  new HashMap<String, String>();
        synuser.put("messageclass", "userClose");// 普通 消息
        synuser.put( "userName",username );
        synMessage(synuser);
        int iin = Integer.parseInt(mess.get("userIndex"));
        Server.userWrite[iin] = null;
      }
      if (s.equals("bye")) {
        writer.write("bye\n");
        writer.flush();
        break;
      }
    }
  }
}

客户端：

package xcvcvcx;

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.Socket;
import java.net.SocketAddress;
import java.nio.charset.StandardCharsets;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.WindowConstants;

public class Client extends JFrame implements ActionListener ,ItemListener {


  private String currentt_userName = null;



  //各种组件
  JLabel jLabelSeverIP,jLabelSeverPort,jLabelReceiveData,jLabelSentData;
  JTextField jTextFieldSeverIP,jTextFieldSeverPort,jTextFieldSentData;
  JButton jButtonSetupSever,jButtonCloseNetwork,jButtonSent;
  JTextArea jTextAreaReceiveData;
  JButton jButtonExit;
  // 当前在线用户部分
  JLabel jLabelOnlinUser;
  JComboBox jComboBoxOnlineUser;
  //组件完毕


  BufferedReader reader;
  BufferedWriter writer;

  // 存储用户信息
  JLabel jLabelusername;
  JTextField jTextFieldusername;



  String userId ;
  Socket sock;
  int userIndex;

  // 服务连接相关
  String ServerAddress ="192.168.43.240" ; // 可以自己设置
  int port = 6666;

  public Client(){
    init();
  }

  public void init(){
    //初始化
    jLabelReceiveData=new JLabel("接受数据:");
    jLabelSentData=new JLabel("发送数据:");
    jLabelSeverIP=new JLabel("服务器IP");
    jLabelSeverPort=new JLabel("服务器端口");
    jTextFieldSentData=new JTextField(15);
    jTextFieldSeverIP=new JTextField(7);
    jTextFieldSeverPort=new JTextField(7);
    jButtonCloseNetwork=new JButton("关闭服务");
    jButtonSent=new JButton("发送");
    jButtonSetupSever=new JButton("开启服务");
    jTextAreaReceiveData=new JTextArea(20,15);
    JScrollPane scroller = new JScrollPane(jTextAreaReceiveData);
    scroller.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
    jTextAreaReceiveData.setWrapStyleWord(true);//设置单词在一行不足容纳时换行
    jTextAreaReceiveData.setLineWrap(true);//设置文本编辑区自动换行默认为true,即会"自动换行"
    //this.add(editArea,BorderLayout.CENTER);//向窗口添加文本编辑区
    jButtonExit = new JButton("退出");

    //组件初始化

    // 存储  用户信息
    jLabelusername = new JLabel("用户名");
    jTextFieldusername = new JTextField(10);
    jLabelOnlinUser = new JLabel("在线用户");
    jComboBoxOnlineUser = new JComboBox();
    jComboBoxOnlineUser.addItemListener(this::itemStateChanged);
    jComboBoxOnlineUser.addItem("self");



    JPanel panel1=new JPanel();
    panel1.setLayout(new FlowLayout());
    panel1.add(jLabelSeverIP);
    panel1.add(jTextFieldSeverIP);
    panel1.add(jLabelSeverPort);
    panel1.add(jTextFieldSeverPort);
    panel1.add(jButtonSetupSever);
    panel1.add(jButtonCloseNetwork);
    JPanel panel2=new JPanel();
    panel2.add(jLabelReceiveData);


    JPanel jPaneluserinfor = new JPanel();
    jPaneluserinfor.setLayout(new FlowLayout());
    jPaneluserinfor.add(jLabelusername);
    jPaneluserinfor.add((jTextFieldusername));
    jPaneluserinfor.add(jLabelOnlinUser);
    jPaneluserinfor.add(jComboBoxOnlineUser);


    JPanel jPanel1=new JPanel();
    jPanel1.setLayout(new GridLayout(3,1));
    jPanel1.add(panel1);
    jPanel1.add(jPaneluserinfor);
    jPanel1.add(panel2);

    JPanel panel3=new JPanel();
    panel3.setLayout(new FlowLayout());
    panel3.add(jLabelSentData);
    JPanel panel4=new JPanel();
    panel4.setLayout(new FlowLayout());
    panel4.add(jTextFieldSentData);
    panel4.add(jButtonSent);
    panel4.add(jButtonExit);

    JPanel jPanel2=new JPanel();
    jPanel2.setLayout(new GridLayout(2,1));
    jPanel2.add(panel3);
    jPanel2.add(panel4);

    JPanel jPanel=new JPanel();
    jPanel.setLayout(new BorderLayout());
    jPanel.add(jPanel1,BorderLayout.NORTH);
    jPanel.add(scroller,BorderLayout.CENTER);
    jPanel.add(jPanel2,BorderLayout.SOUTH);
    //完成组件组合

    jButtonSent.addActionListener(this);
    jButtonSetupSever.addActionListener(this);
    jButtonCloseNetwork.addActionListener(this);
    jButtonExit.addActionListener(this);


    setSize(600,400);
    setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    add(jPanel);
    setVisible(true);
    //显示
    jButtonCloseNetwork.setEnabled(false);

    jTextFieldSeverIP.setText(ServerAddress);
    jTextFieldSeverPort.setText(String.valueOf(port));
    jTextAreaReceiveData.append("本程序只用于简单演示，\n若要修改服务器地址或端口，请修改指定代码，暂不支持手动指定\n\n\n");

    // 连接服务器
    try {
      Socket sock = new Socket(ServerAddress, port);
      this.sock = sock;
      try (InputStream input = sock.getInputStream()) {
        try (OutputStream output = sock.getOutputStream()) {
          BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(output, StandardCharsets.UTF_8));
          BufferedReader reader = new BufferedReader(new InputStreamReader(input, StandardCharsets.UTF_8));
          SocketAddress id =  sock.getRemoteSocketAddress();
          userId = sock.getRemoteSocketAddress().toString();
          this.writer =writer;
          this.reader = reader;
          while(true)
            for (; ; ) {
              String resp = reader.readLine();
              while (resp == null) {
                resp = reader.readLine();
              }
              System.out.println("<<< " + resp);
              Map<String, String> message = mapStringToMap(resp);
              if (message.get("messageclass").equals("synId")) {
                System.out.println(userId);
                userId = message.get("userId");
                System.out.println(message.keySet());
                System.out.println(userId);
                // 更新 服务器 接口 处的  内容
                jTextAreaReceiveData.append("已为您成功分配id  请填写用户名，并开启服务");
                jTextAreaReceiveData.append(resp);
                jTextAreaReceiveData.append("\n");
                userIndex = Integer.parseInt(message.get("userIndex"));
                continue;
              } else if (message.get("messageclass").equals("normally")) {
                resp = message.toString();
                System.out.print("748328");
                // 正常消息
                String showMess = "";
                String dist = message.get("distination");
                if (dist.equals("all")){
                  showMess = showMess.concat("消息类型:全体消息" + '\n');

                }else {
                  showMess = showMess.concat("消息类型:私发消息" + '\n');
                }
                showMess = showMess.concat("消息时间: " + message.get("time") +  '\n');
                showMess = showMess.concat("消息内容: " + message.get("content") +  '\n');
                showMess = showMess.concat("消息来源: " + message.get("user") +  '\n');
                jTextAreaReceiveData.append(showMess);
                jTextAreaReceiveData.append("\n\n");



              } else if (message.get("messageclass").equals("addUser")) {
                if (currentt_userName ==null){
                  continue;
                }
                System.out.println(message.toString());
                String newname = message.get("userName");
                if (newname.equals(currentt_userName) == false) {
                  jComboBoxOnlineUser.addItem(newname);
                  jTextAreaReceiveData.append("有新用户上线了：他是: " + newname + "\n\n" );
                }


              } else if (message.get("messageclass").toString().equals("userClose")) {
                String name = message.get("userName");
                System.out.println("现在 删除 user: " + name);
                jTextAreaReceiveData.append("有用户下线了：他是: " + name + "\n\n" );
                jComboBoxOnlineUser.removeItem(name);
              }else if( message.get("messageclass").toString().equals("synUserList") ){
                String Lis = message.get("userList");
                String[] UserList = Lis.split(" ");
                int i;
                for(i=1; i<UserList.length;i++) {
                  jComboBoxOnlineUser.addItem(UserList[i]);
                }

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

  public static Map<String,String> mapStringToMap(String str){
    str=str.substring(1, str.length()-1);
    System.out.println("ishere dk->" + str);
    String[] strs=str.split(",");
    Map<String,String> map = new HashMap<String, String>();
    for (String string : strs) {
      String key=string.split("=")[0];
      String value=string.split("=")[1];
      value = value.trim();
      key = key.trim();
      map.put(key, value);
    }
    return map;
  }


  public static void main(String[] args) throws IOException {
     Client a = new Client();
  }


  private static void handle(InputStream input, OutputStream output) throws IOException {
    BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(output, StandardCharsets.UTF_8));
    BufferedReader reader = new BufferedReader(new InputStreamReader(input, StandardCharsets.UTF_8));
    Scanner scanner = new Scanner(System.in);
    System.out.println("[server] " + reader.readLine());
    for (;;) {
      System.out.print(">>> "); // 打印提示
      String s = scanner.nextLine(); // 读取一行输入
      writer.write(s);
      writer.newLine();
      writer.flush();
      String resp = reader.readLine();
      System.out.println("<<< " + resp);
      if (resp.equals("bye")) {
        break;
      }
    }
  }
  void update() throws IOException {
    for (;;) {
      System.out.print("lkdfvmndfjk");
      String resp = reader.readLine();
      System.out.println("<<< " + resp);
      jTextAreaReceiveData.append(resp);
      if (resp.equals("bye")) {
        break;
      }
    }
  }

  static String time (){
    SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//设置日期格式
    return df.format( new Date() ).toString();
  }

  @Override
  public void actionPerformed(ActionEvent e) {
    if (e.getSource()==jButtonSent){
        if (jTextFieldSentData.getText() == "") {
          jTextAreaReceiveData.append("发送不可为空"+"\n");
        }else {
          this.currentt_userName = jTextFieldusername.getText().toString();
          Map<String,String> message=  new HashMap<String, String>();
          message.put("messageclass", "normally");// 普通 消息
          message.put("user",currentt_userName);
          message.put( "userId",userId );
          String  to=jTextFieldSentData.getText();
          message.put("content",to);
          message.put("time",time());
          String distina =   jComboBoxOnlineUser.getSelectedItem().toString();
          if (distina.equals("self")){
            // 发给所有人
            System.out.println("查看");
            message.put("distination","all");
          }else {
            // 发给某人
            message.put("distination",distina);
          }



          String ans  = message.toString();
          to = ans;
          try {
            writer.write(to+"\n");
            writer.flush();
          }catch (Exception ee){
            System.out.println(ee.toString());
            jTextAreaReceiveData.append("发送失败"+"\n");
          }
        }
      }else if (e.getSource() == jButtonCloseNetwork){
      try {
        sock.close();
      } catch (IOException e1) {
        e1.printStackTrace();
      }


    }else if(e.getSource() == jButtonSetupSever){
      String name = jTextFieldusername.getText();
      if (name.equals("")){
        jTextAreaReceiveData.append("用户名不可为空");
        // 不可为空  提示
        return;
      }
      currentt_userName = name;
      Map<String,String> message=  new HashMap<String, String>();
      message.put("messageclass", "synUserName");// 普通 消息
      message.put("user",currentt_userName);
      message.put( "userId",userId );
      message.put( "userIndex",String.valueOf(userIndex) );
      try {
        writer.write(message.toString()+"\n");
        writer.flush();
        jButtonCloseNetwork.setEnabled(true);
        jButtonSetupSever.setEnabled(false);
      } catch (IOException e1) {
        e1.printStackTrace();
      }
      // 同步  用户名

    }else if (e.getSource()== jButtonExit){
      // 关闭按钮
      Map<String,String> message=  new HashMap<String, String>();
      message.put("messageclass", "userClose");// 普通 消息
      message.put("user",currentt_userName);
      message.put( "userId",userId );
      message.put( "userIndex",String.valueOf(userIndex) );
      try {
        writer.write(message.toString()+"\n");
        writer.flush();
        System.out.println(message.toString());
      } catch (IOException e1) {
        e1.printStackTrace();
      }// 发送下线消息

      jComboBoxOnlineUser.removeAllItems();
    }

  }

  @Override
  public void itemStateChanged(ItemEvent e) {

  }
}

里面的ip地址 我写的是我自己的 想改的可以自己改

演示视频放B站了： https://www.bilibili.com/video/BV1JL411j7E1/