點擊下圖註冊按鈕，出現註冊用戶面板，把手機號和判斷相同的密碼添加到MySQL數據庫中

工作原理:

與單機的軟件不同，這個聊天的登錄框不能把註冊信息直接添加進數據庫

而是應當把註冊信息發送到服務器

當服務器接收到註冊信息後，在服務端把註冊信息添加進數據庫

首先，做連接數據庫的準備

連接數據庫需要一個連接數據庫的驅動包 —— mysql-connector-java-5.1.7-bin.jar

如果忘記倒入連接mysql數據庫的包，會出現java.lang.ClassNotFoundException: com.mysql.jdbc.Driver問題

下載地址：鏈接: https://pan.baidu.com/s/1geBRqqn 密碼: 8jxm

然後，把連接數據庫的語句做成工具類，方便調用

DBUtil類，負責連接已經存在的數據庫sw_database（用DBUtil.getConn()方法）

　　　　 負責連接數據庫後關閉各種資源（用DBUtil.closeAll()方法）

package com.swift.jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

 
public class DBUtil {
    
    public static Connection getConn() {
        Connection conn=null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
 
try {
            String url="jdbc:mysql://localhost:3306/sw_database";
            String user="root";
            String password="root";
            conn=DriverManager.getConnection(url, user, password);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }
    
    public static void closeAll(Connection conn,PreparedStatement ps,ResultSet rs) {
        
        if(conn!=null) {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(ps!=null) {
            try {
                ps.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(rs!=null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}

接著，需要把用戶註冊的信息添加進數據庫的sw_user表中

所以，再建一個工具類DBAdd，負責添加用戶註冊信息到表中（用DBAdd.add(User user)方法）

package com.swift.jdbc;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class DBAdd {
    
    public static void add(User user) {
        
        String phone = user.getUsername();
        String password = user.getPassword();
        
        Connection conn = DBUtil.getConn();
        PreparedStatement ps=null;
        try {
            ps = conn.prepareStatement("insert into sw_user(username,password) values(?,?)");
            ps.setString(1, phone);
            ps.setString(2, password);
            int count = ps.executeUpdate();
            if (count == 1) {
                System.out.println("用戶添加成功");
            } else {
                System.out.println("用戶添加失敗");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            DBUtil.closeAll(conn, ps, null);
        }
        
    }

}

User類代碼如下：負責用戶信息的包裝

package com.swift.jdbc;

public class User {
    
    private int id;
    private String username;
    private String password;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public User(int id, String username, String password) {
        this.id = id;
        this.username = username;
        this.password = password;
    }
    public User() {
        super();
    }
    public User(String username, String password) {
        this.username = username;
        this.password = password;
    }
    @Override
    public String toString() {
        return "User [id=" + id + ", username=" + username + ", password=" + password + "]";
    }
    
}

接著，在LoginDialog登陸窗口“註冊用戶”按鈕添加監聽，當點擊按鈕則把信息發送給服務端

信息發給服務端，需要建立與服務端的連接，及關閉窗口斷開連接

連接後分別發送電話號碼和驗證好的密碼

具體代碼如下：

package com.swift.frame;

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ConnectException;
import java.net.Socket;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;

import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.TitledBorder;

import com.swift.jdbc.DBAdd;
import com.swift.jdbc.DBUtil;
import com.swift.jdbc.User;
import com.swift.util.Center;

public class LoginDialog extends JDialog {

    private JPasswordField passwordField_2;
    private JPasswordField passwordField_1;
    private JTextField textField_2;
    private JTextField textField;
    
    Socket s;
    DataOutputStream dos;
    DataInputStream dis;

    public static void main(String args[]) {
        JFrame.setDefaultLookAndFeelDecorated(true);
        JDialog.setDefaultLookAndFeelDecorated(true);

        try {
            UIManager.setLookAndFeel("javax.swing.plaf.nimbus.NimbusLookAndFeel");
        } catch (ClassNotFoundException e1) {
            e1.printStackTrace();
        } catch (InstantiationException e1) {
            e1.printStackTrace();
        } catch (IllegalAccessException e1) {
            e1.printStackTrace();
        } catch (UnsupportedLookAndFeelException e1) {
            e1.printStackTrace();
        }

        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    LoginDialog dialog = new LoginDialog();
                    dialog.addWindowListener(new WindowAdapter() {
                        public void windowClosing(WindowEvent e) {
                            System.exit(0);
                        }
                    });
                    dialog.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    public LoginDialog() {
        super();
        setResizable(false);
        setTitle("在線聊天登錄框");
        getContentPane().setLayout(null);
        setBounds(100, 100, 427, 301);// 註冊時高度為578，不註冊是301

        // 設置窗口居中
        this.setLocation(Center.getPoint(this.getSize()));

        final JButton button_1 = new JButton();
        button_1.setText("登錄");
        button_1.setBounds(230, 222, 106, 36);
        getContentPane().add(button_1);

        final JTextField textField_1 = new JTextField();
        textField_1.setBounds(148, 90, 192, 42);
        getContentPane().add(textField_1);

        final JLabel label = new JLabel();
        label.setText("帳    號");
        label.setBounds(76, 102, 66, 18);
        getContentPane().add(label);

        final JLabel label_1 = new JLabel();
        label_1.setText("密    碼");
        label_1.setBounds(76, 167, 66, 18);
        getContentPane().add(label_1);

        final JPasswordField passwordField = new JPasswordField();
        passwordField.setBounds(148, 155, 192, 42);
        getContentPane().add(passwordField);

        final JButton button = new JButton();
        button.addActionListener(new ActionListener() {
            public void actionPerformed(final ActionEvent e) {
                if (LoginDialog.this.getHeight() == 301) {
                    LoginDialog.this.setSize(427, 578);
                } else {
                    LoginDialog.this.setSize(427, 301);
                }
                // 設置窗口不斷居中
                LoginDialog.this.setLocation(Center.getPoint(LoginDialog.this.getSize()));
            }
        });
        button.setText("註冊");
        button.setBounds(76, 222, 106, 36);
        getContentPane().add(button);

        final JPanel panel = new JPanel();
        panel.setLayout(null);
        panel.setBorder(new TitledBorder(null, "註冊用戶", TitledBorder.DEFAULT_JUSTIFICATION,
                TitledBorder.DEFAULT_POSITION, null, null));
        panel.setBounds(10, 278, 401, 226);
        getContentPane().add(panel);

        final JLabel label_2 = new JLabel();
        label_2.setBounds(44, 41, 65, 18);
        label_2.setText("手機號：");
        panel.add(label_2);

        textField = new JTextField();
        textField.setBounds(115, 35, 225, 30);
        panel.add(textField);

        final JButton button_2 = new JButton();
        button_2.setText("發送驗證");
        button_2.setBounds(243, 75, 97, 30);
        panel.add(button_2);

        textField_2 = new JTextField();
        textField_2.setBounds(115, 104, 95, 30);
        panel.add(textField_2);

        final JLabel label_3 = new JLabel();
        label_3.setText("驗證碼：");
        label_3.setBounds(44, 110, 65, 18);
        panel.add(label_3);

        passwordField_1 = new JPasswordField();
        passwordField_1.setBounds(115, 143, 231, 30);
        panel.add(passwordField_1);

        passwordField_2 = new JPasswordField();
        passwordField_2.setBounds(115, 175, 231, 30);
        panel.add(passwordField_2);

        final JLabel label_4 = new JLabel();
        label_4.setText("密        碼：");
        label_4.setBounds(44, 149, 65, 18);
        panel.add(label_4);

        final JLabel label_5 = new JLabel();
        label_5.setText("驗證密碼：");
        label_5.setBounds(44, 181, 65, 18);
        panel.add(label_5);

        final JButton button_3 = new JButton();
        button_3.setBounds(47, 510, 97, 30);
        getContentPane().add(button_3);
        button_3.setText("放棄");

        final JButton button_4 = new JButton();
        button_4.addActionListener(new ActionListener() {
            public void actionPerformed(final ActionEvent e) {
                
                String phone = textField.getText();
                String password = null;
                String str1=new String(passwordField_1.getPassword()).trim();
                String str2=new String(passwordField_2.getPassword()).trim();
                
                if (str1.equals(str2)) {
                    password = new String(passwordField_2.getPassword()).trim();
                } else {
                    System.out.println("輸入密碼不一致...");
                    System.exit(0);
                }
                try {
                    dos.writeUTF(phone);
                    dos.writeUTF(password);
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
            }
        });
        
        button_4.setBounds(262, 510, 97, 30);
        getContentPane().add(button_4);
        button_4.setText("註冊用戶");
        
        connect();
        this.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosed(WindowEvent e) {
                disconnect();
            }
        });
    }
    
    public void connect() {
        try {
            s = new Socket("127.0.0.1", 8888);
            System.out.println("一個客戶端登陸中....!");
            dos = new DataOutputStream(s.getOutputStream());
            dis = new DataInputStream(s.getInputStream());

        } catch (ConnectException e) {
            System.out.println("服務端異常.........");
            System.out.println("請確認服務端是否開啟.........");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void disconnect() {
        try {
            if (dos != null)
                dos.close();
            if (s != null)
                s.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
        

}

服務端要接受客戶端登陸窗發來的手機號碼和密碼

然後將信息打包成User，通過DBAdd.add(user)添加進數據庫

建立一個LoginServer類，負責接收信息和添加進數據庫

具體代碼如下：

package com.swift;


import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.EOFException;
import java.io.IOException;
import java.net.BindException;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;

import com.swift.jdbc.DBAdd;
import com.swift.jdbc.User;

public class LoginServer {
    
    boolean started = false;
    ServerSocket ss = null;
    Socket s = null;
    
    public static void main(String[] args) {
        new LoginServer().fun();
    }

    private void fun() {
        try {
            ss = new ServerSocket(8888);
            started = true;
        } catch (BindException e) {
            System.out.println("端口使用中......");
        } catch (IOException e1) {
            e1.printStackTrace();
        }
        try {
            while (started) {
                s = ss.accept();
                System.out.println("a client connected success");
                Client c = new Client(s);
                new Thread(c).start();
            }
        } catch (EOFException e) {
            System.out.println("client has closed.");
        } catch (Exception 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;
        private DataOutputStream dos;
        private boolean connected = false;

        public Client(Socket s) {
            this.s = s;
            try {
                this.dis = new DataInputStream(s.getInputStream());
                this.dos = new DataOutputStream(s.getOutputStream());
                connected = true;
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        @Override
        public void run() {
            try {//註意:要包括while循環，如果try在while循環裏，則出現socket closed異常
                while (connected) {
                    String phone = dis.readUTF();
                    String password = dis.readUTF();
                    
                    System.out.println(phone);
                    System.out.println(password);
                    
                    User user=new User(phone,password);
                    DBAdd.add(user);
                }
            } catch(SocketException e) {
                System.out.println("一個登陸窗已經關閉....");
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                  if (s != null) {
                      try {
                          s.close();
                      } catch (IOException e) {
                          e.printStackTrace();
                      }
                  }
                if (dis != null) {
                    try {
                        dis.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                if(dos!=null) {
                    try {
                        dos.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }

        }

    }
}

效果圖：

打開多個登陸窗口，分別註冊用戶後關閉，服務端提示信息如下：

java在線聊天項目 客戶端登陸窗口LoginDialog的註冊用戶功能