java聊天室连接数据库

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

public class ChatRoomDB {
    private static final String DB_URL = "jdbc:mysql://localhost:3306/chatroom";
    private static final String USER = "root";
    private static final String PASS = "password";

    public static void main(String[] args) {
        Connection conn = null;
        PreparedStatement pstmt = null;
        ResultSet rs = null;

        try {
            // 加载MySQL驱动
            Class.forName("com.mysql.cj.jdbc.Driver");

            // 建立数据库连接
            conn = DriverManager.getConnection(DB_URL, USER, PASS);

            // 查询用户信息
            String sql = "SELECT * FROM users WHERE username = ?";
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, "admin");
            rs = pstmt.executeQuery();

            while (rs.next()) {
                System.out.println("User ID: " + rs.getInt("id"));
                System.out.println("Username: " + rs.getString("username"));
                System.out.println("Email: " + rs.getString("email"));
            }
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        } finally {
            // 关闭资源
            try {
                if (rs != null) rs.close();
                if (pstmt != null) pstmt.close();
                if (conn != null) conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}