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java 局域网聊天

發布時間：2023/12/18 编程问答 33 豆豆

生活随笔收集整理的這篇文章主要介紹了 java 局域网聊天小編覺得挺不錯的,現在分享給大家,幫大家做個參考.

局域網聊天軟件

需要的前置了解：

了解java窗體
了解Socket通信
了解線程使用
了解TCP協議
只要你能了解以上內容，通過自身的應用，即可實現一個簡單的局域網聊天軟件。

聊天軟件實現難點

本項目中

客戶端向服務端發送的數據分3種：

聊天信息
新加入的用戶姓名（未完善）
退出的用戶姓名

服務端向客戶端發送的數據分4種：

聊天信息
有用戶加入
服務器斷開
由用戶退出

在本項目中會對發送的數據進行處理，在每個數據前加上一個標識，以便判斷是何種情況的數據。

服務器

一開始選擇服務器作為第一個實現的目標，實現步驟如下：

設計服務器窗口；

添加對應窗口監聽器（關閉服務器時斷開客戶端連接）；

補充監聽器按鈕邏輯（創建服務器及發送信息）；

創建額外的線程，循環獲取客戶端信息。

大體思路就是這個，詳細實現（為了方便理解，按照調用方法的順序來展現代碼）：

public class ChatServerFrame extends JFrame implements ActionListener{//此處設計其實不太好，沒有實現封裝，日后需注意static String mString;static JTextArea ChatWindow;JTextArea InputMessage;static JTextArea UserName;//存儲用戶名稱ArrayList<String> Userlist = new ArrayList<String>();//存儲所有的客戶端連接，以便之后進行使用ArrayList<Socket> socketList = new ArrayList<Socket>();JTextField getPort;String Ip;String stringPort;int port;ServerSocket serverSocket = null;static boolean judge;public static void main(String[] args) {ChatServerFrame chatFrame = new ChatServerFrame();chatFrame.setVisible(true);}//窗口實現（不是很重要）public ChatServerFrame() {setTitle("服務器聊天窗口");setSize(700, 550);setLocationRelativeTo(null);setLayout(new FlowLayout());try {Ip = Inet4Address.getLocalHost().getHostAddress();} catch (UnknownHostException e) {// TODO Auto-generated catch blocke.printStackTrace();}JPanel jPanel = new JPanel(new BorderLayout());//消息顯示區(莫名其妙就成繁體字了....)JPanel jp1 = new JPanel(new BorderLayout());ChatWindow = new JTextArea(17, 45);ChatWindow.setEditable(false);ChatWindow.setLineWrap(true);JScrollPane scrollPane = new JScrollPane(ChatWindow);jp1.setBorder(new TitledBorder("消息顯示"));jp1.add(scrollPane,"Center");//發出信息框JPanel jp2Top = new JPanel(new BorderLayout());JPanel jp2_1 = new JPanel(new BorderLayout());JPanel jp2_2 = new JPanel(new BorderLayout());JToolBar toolBar = new JToolBar();JLabel linkServer = new JLabel("服務器Ip");JTextField getServer = new JTextField(12);JLabel linkPort = new JLabel("端口");getPort = new JTextField(12);JButton createServer = new JButton("創建服務器");getServer.setText(Ip);getServer.setEditable(false);InputMessage = new JTextArea(5,45);InputMessage.setLineWrap(true);createServer.addActionListener(this);JScrollPane scrollPane2 = new JScrollPane(InputMessage);toolBar.add(linkServer);toolBar.add(getServer);toolBar.add(linkPort);toolBar.add(getPort);toolBar.add(createServer);jp2_1.setBorder(new TitledBorder("信息輸入"));jp2_2.add(toolBar,"North");jp2_1.add(scrollPane2,"Center");jp2Top.add(jp2_2,"North");jp2Top.add(jp2_1,"Center");//按鈕區JPanel jp3 = new JPanel();JButton send = new JButton("發送");send.addActionListener(this);jp3.add(send);//用戶區JPanel jp4 = new JPanel(new BorderLayout());jp4.setBorder(new TitledBorder("用戶區"));UserName = new JTextArea(29,8);UserName.setEditable(false);JScrollPane scrollPane3 = new JScrollPane(UserName);jp4.add(scrollPane3);jPanel.add(jp1,"North");jPanel.add(jp2Top,"Center");jPanel.add(jp3,"South");this.add(jp4);this.add(jPanel);//添加窗口監聽器，主要設置關閉窗口時，斷開各個客戶端的連接WindowAction windowAction = new WindowAction();this.addWindowListener(windowAction);//將服務器姓名傳上String name = "服務器";Userlist.add(name);UserName.append(name + "\n"); }//此處是想著為之后的登陸留接口，并無用處public ChatServerFrame(String mString) {this.mString = mString;}... ...//添加窗口監聽器class WindowAction extends WindowAdapter {//在窗口關閉時，斷開和所有客戶端的連接@Overridepublic void windowClosing(WindowEvent e) {//如果已經創建服務端并服務端未關閉if (serverSocket != null && (!serverSocket.isClosed())) { //TODO 向所有用戶發送用戶退出的信息，此處可更優化for (String string : Userlist) {try {sendAllClient(string, 4);} catch (IOException e1) {e1.printStackTrace();}}try {//發送服務端退出信息sendAllClient(null, 3);} catch (IOException e2) {e2.printStackTrace();}//關閉和客戶端的連接for (Socket socket : socketList) {try {socket.close();} catch (IOException e1) {e1.printStackTrace();}}Userlist.clear();try {serverSocket.close();} catch (IOException e1) {e1.printStackTrace();}System.exit(0);}super.windowClosing(e);}}//添加按鈕監聽器@Overridepublic void actionPerformed(ActionEvent e) {String cmd = e.getActionCommand();if (cmd.equals("創建服務器")) {if (serverSocket != null) {JOptionPane.showMessageDialog(this, "已經創建好服務器！");} else {stringPort = getPort.getText().toString();if (stringPort.isEmpty()) {JOptionPane.showMessageDialog(this, "端口不能為零");} else {port = Integer.parseInt(getPort.getText().toString());createServer();}}} else if (cmd.equals("發送")) {if (InputMessage.getText().toString().isEmpty()) {JOptionPane.showMessageDialog(this, "不能發送空信息！");} else if (socketList.isEmpty()) {JOptionPane.showMessageDialog(null, "沒有用戶連接，不能發信息");} else {String message = "服務端: " + InputMessage.getText().toString();ChatWindow.append(message + "\n");try {//此處的1在接受客戶端數據處有注釋解釋（class ReceiveClient）sendAllClient(message, 1);} catch (IOException e1) {JOptionPane.showMessageDialog(this, "沒有客戶端連接");}}InputMessage.setText("");}}//承接上文的創建服務器public void createServer() {try {serverSocket = new ServerSocket(port);JOptionPane.showMessageDialog(this, "服務器創建成功！");//創建一個單獨的線程，用來接收客戶端的連接new LinkClient(serverSocket).start();} catch (IOException e) {JOptionPane.showMessageDialog(this, "服務器創建失敗！請修改端口或重啟");e.printStackTrace();}}//將服務器的信息發送給所有客戶端，此處的flag是為了判斷發送數據的類型public void sendAllClient(String message,int flag) throws IOException {String info = flag + message;PrintWriter printWriter = null;for (Socket socket : socketList) {printWriter = new PrintWriter(socket.getOutputStream(), true);printWriter.println(info);}}... //對客戶端的邏輯，接受客戶端連接class LinkClient extends Thread{ServerSocket serverSocket;public LinkClient(ServerSocket serverSocket) {this.serverSocket = serverSocket;}@Overridepublic void run() {//TODO 此處應該有比while(true)更好的方法，但我暫時不會while(true) {try {//此處會阻塞該進程，直到獲取到客戶端連接（查看源碼之后，仍不清楚accept是如何阻塞的，據網上說法，是有一個while(Listen())一直在運行）Socket socket = serverSocket.accept();socketList.add(socket);//將新加入用戶的名稱發給此時的其他用戶for (String string : Userlist) {sendAllClient(string, 2);}//新建一個線程，接收客戶端的信息//此處的邏輯是每接收一個客戶端就創建一個線程new ReceiveClient(socket).start();//TODO 連接數據庫，將socket的IP地址傳入，與數據庫中的名稱進行比較 OR 在剛開始連接時，首先將姓名傳出來} catch (IOException e) {JOptionPane.showMessageDialog(null, "服務器已退出！");e.printStackTrace();}}}}//接受客戶端的數據class ReceiveClient extends Thread {Socket socket;public ReceiveClient(Socket socket) {this.socket = socket;}@Overridepublic void run() {try {//等待接受該socket發送的數據BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(socket.getInputStream()));//TODO 循環接受之后的數據while(true) {try {int flag = bufferedReader.read() - '0';String message = bufferedReader.readLine();/** 當從客戶端接收信息時，讀取第一個字符，若為* 1，則之后的字符串為客戶發送的信息接收信息* 2，則之后的字符串為新加入的客戶的姓名添加新用戶* 3，則之后的字符串為退出的客戶的姓名刪除用戶*/switch (flag) {case 1:ChatWindow.append(message + "\n");sendAllClient(message, 1);break;case 2:if (!Userlist.contains(message))Userlist.add(message);UserName.setText("");for(String string : Userlist) {UserName.append(string + "\n");sendAllClient(string, 2);try {sleep(1000);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}}break;case 3:Userlist.remove(message);UserName.setText("");for(String string : Userlist) {System.out.println(string);UserName.append(string + "\n");}socketList.remove(socket);sendAllClient(message, 4);break;default:break;}} catch (IOException e) {e.printStackTrace();break;}}} catch (IOException e1) {// TODO Auto-generated catch blocke1.printStackTrace();}}}

客戶端

做完服務器之后，繼續完成客戶端內容（此處建議：在完成服務器的ServerSocket()內容后，寫一個簡單的客戶端，用于測試相關功能）；實現步驟如下：

設計客戶端窗口（此處的客戶端窗口和服務端類似，建議寫一個復用性較強的方法，不過并未寫）；

添加對應窗口監聽器（關閉客戶端時斷開服務器連接）；

補充監聽器按鈕邏輯（連接服務器、發送信息）；

創建額外的線程，循環獲取服務端信息。
額外內容：實現了查詢局域網內服務器ip

//設計客戶端窗口 public class ChatFrame extends JFrame implements ActionListener {public static Socket socket = null;String serverIp;String stringPort;int serverPort;public static JTextArea chatWindow;JTextArea inputMessage;public static JTextArea userName;JTextField inputServer;JTextField inputPort;JTextField inputFindPort;String Id = "123";public static void main(String[] args) {ChatFrame chatFrame = new ChatFrame();chatFrame.setVisible(true);}public ChatFrame() {setTitle("聊天窗口");setSize(700, 550);setLocationRelativeTo(null);setLayout(new FlowLayout());JPanel jPanel = new JPanel(new BorderLayout());// 消息顯示區(莫名其妙就成繁體字了....)JPanel jp1 = new JPanel(new BorderLayout());chatWindow = new JTextArea(17, 45);chatWindow.setEditable(false);chatWindow.setLineWrap(true);JScrollPane scrollPane = new JScrollPane(chatWindow);jp1.setBorder(new TitledBorder("消息顯示"));jp1.add(scrollPane, "Center");// 發出信息框JPanel jp2Top = new JPanel(new BorderLayout());JPanel jp2_1 = new JPanel(new BorderLayout());JPanel jp2_2 = new JPanel(new BorderLayout());JToolBar toolBar = new JToolBar();JLabel linkServer = new JLabel("服務器");inputServer = new JTextField();JLabel linkPort = new JLabel("端口");inputPort = new JTextField();JButton createServer = new JButton("連接服務器");JLabel findPort = new JLabel("查找端口");inputFindPort = new JTextField();JButton findServer = new JButton("查找服務器");inputMessage = new JTextArea(5, 45);inputMessage.setLineWrap(true);createServer.addActionListener(this);findServer.addActionListener(this);JScrollPane scrollPane2 = new JScrollPane(inputMessage);toolBar.add(linkServer);toolBar.add(inputServer);toolBar.add(linkPort);toolBar.add(inputPort);toolBar.add(createServer);toolBar.add(findPort);toolBar.add(inputFindPort);toolBar.add(findServer);jp2_1.setBorder(new TitledBorder("信息輸入"));jp2_2.add(toolBar, "North");jp2_1.add(scrollPane2, "Center");jp2Top.add(jp2_2, "North");jp2Top.add(jp2_1, "Center");// 按鈕區JPanel jp3 = new JPanel();JButton send = new JButton("發送");send.addActionListener(this);jp3.add(send);// 用戶區JPanel jp4 = new JPanel(new BorderLayout());jp4.setBorder(new TitledBorder("用戶區"));userName = new JTextArea(29, 8);userName.setEditable(false);JScrollPane scrollPane3 = new JScrollPane(userName);jp4.add(scrollPane3);jPanel.add(jp1, "North");jPanel.add(jp2Top, "Center");jPanel.add(jp3, "South");this.add(jp4);this.add(jPanel);// 添加窗口監聽器WindowAction windowAction = new WindowAction();this.addWindowListener(windowAction);} //窗口監聽器內容class WindowAction extends WindowAdapter {//關閉窗口時，斷開和服務端的連接@Overridepublic void windowClosing(WindowEvent e) {//如果已經和服務端連接并且連接未斷開if (socket != null && (!socket.isClosed())) {//向服務端發送斷開信息PrintWriter os;try {os = new PrintWriter(socket.getOutputStream());os.println("3" + Id);//強制刷出緩存，保證數據立馬發送os.flush();} catch (IOException e1) {// TODO Auto-generated catch blocke1.printStackTrace();}try {socket.close();} catch (IOException e1) {// TODO Auto-generated catch blocke1.printStackTrace();}}System.exit(0);super.windowClosing(e);}}//設置按鈕監聽邏輯 @Overridepublic void actionPerformed(ActionEvent e) {String cmd = e.getActionCommand();serverIp = inputServer.getText().toString();stringPort = inputPort.getText().toString();if (cmd.equals("連接服務器")) {if (socket != null) {JOptionPane.showMessageDialog(this, "已經連接服務器！");} else {if (serverIp.isEmpty() || stringPort.isEmpty()) {JOptionPane.showMessageDialog(null, "IP和端口不能為空！");} else {serverPort = Integer.parseInt(inputPort.getText().toString());linkServer();}}} else if (cmd.equals("發送")) {if (inputMessage.getText().toString().isEmpty()) {JOptionPane.showMessageDialog(this, "不能發送空的信息！");} else if (socket == null){JOptionPane.showMessageDialog(this, "未連接服務器，不能發送信息！");} else {String message = Id + ": " + inputMessage.getText().toString();try {new SendMessage(socket, message, 1);} catch (IOException e1) {JOptionPane.showMessageDialog(this, "未連接服務器！");}}inputMessage.setText("");} else if (cmd.equals("查找服務器")) {int IntfindPort = Integer.parseInt(inputFindPort.getText().toString());//此處的代碼放在最后new Port().getNeedIp(IntfindPort);}}public void linkServer() {System.out.println(serverIp + " " + serverPort);try {socket = new Socket(serverIp, serverPort);JOptionPane.showMessageDialog(this, "連接成功！");//發送用戶連接信息new SendMessage(socket, Id, 2);//開啟接收信息線程new ReceiveServer(socket, Id).start();} catch (UnknownHostException e) {JOptionPane.showMessageDialog(this, "連接未成功！可能是ip或端口號格式不對，或服務器未開啟！");e.printStackTrace();} catch (IOException e) {JOptionPane.showMessageDialog(this, "連接未成功！可能是ip或端口號格式不對，或服務器未開啟！");e.printStackTrace();}} //接收服務端發出的信息 class ReceiveServer extends Thread {Socket socket;ArrayList<String> userList = new ArrayList<String>();public ReceiveServer(Socket socket, String id) {this.socket = socket;userList.add(id);}@Overridepublic void run() {while (true) {try {BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(socket.getInputStream()));int flag = bufferedReader.read() - '0';String message = bufferedReader.readLine();/** 接收的信息分幾種情況 1、聊天信息 2、有用戶加入 3、服務器斷開 4、有用戶退出*/switch (flag) {case 1:ChatFrame.chatWindow.append(message + "\n");break;case 2:if (!userList.contains(message))userList.add(message);ChatFrame.userName.setText("");for (String string : userList) {ChatFrame.userName.append(string + "\n");}break;case 3:ChatFrame.socket.close();JOptionPane.showMessageDialog(null, "服務器已經退出！");socket = null;break;case 4:userList.remove(message);ChatFrame.userName.setText("");for (String string : userList) {ChatFrame.userName.append(string + "\n");}break;default:break;}} catch (IOException e) {JOptionPane.showMessageDialog(null, "服務端已退出連接！");e.printStackTrace();break;}}} } //為發出的信息加標識 class SendMessage {public SendMessage(Socket socket, String message, int flag) throws IOException {String info = flag + message;PrintWriter os = new PrintWriter(socket.getOutputStream());os.println(info);os.flush();} }

額外內容

獲取開啟對應端口的服務器

讀取本地IP地址，獲取除去主機號之后的字符串；

開啟多個線程，嘗試連接該局域網下所有主機，連接成功后斷開連接。

public class Port { static int threadCount = 0;static String temp = null;static ArrayList<String> ipList = new ArrayList<String>();public Port() {}public Port(String temp) {this.temp = temp;}public void putList() {ipList.add(temp);}public static void wait(String iip,int port) throws Exception {while (threadCount > 50) {Thread.sleep(50);}threadCount++;getIp ip = new getIp(iip, port);ip.start();}public static void get(int port) throws UnknownHostException, InterruptedException {InetAddress host = InetAddress.getLocalHost();String hostAddress = host.getHostAddress();int k = 0;k = hostAddress.lastIndexOf(".");String ss = hostAddress.substring(0, k + 1);for (int i = 1; i <= 255; i++) { // 對所有局域網IpString iip = ss + i;try {wait(iip, port);} catch (Exception e) {e.printStackTrace();}}while(threadCount > 0)Thread.sleep(10);}public void clearList() {this.ipList.clear();}public static void getNeedIp(int port){ try {get(port);} catch (UnknownHostException e) {e.printStackTrace();}catch (InterruptedException e) {e.printStackTrace();}new FindServer(ipList).setVisible(true);} } class getIp extends Thread {public String iip;public int port;public getIp(String iip, int port) {this.iip = iip;this.port = port;}@Overridepublic void run() {Socket connect = new Socket();try {connect.connect(new InetSocketAddress(iip, port),100);new Port(iip).putList();System.out.println(iip + "true");} catch (IOException e) {} finally { try { connect.close(); } catch (IOException e) { e.printStackTrace(); } }new Port().threadCount--;} }

總結

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