java mysql预处理

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

public class PreparedStatementExample {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/mydatabase";
        String username = "myuser";
        String password = "mypassword";
        String sql = "SELECT * FROM users WHERE username = ? AND password = ?";

        try (Connection conn = DriverManager.getConnection(url, username, password);
             PreparedStatement pstmt = conn.prepareStatement(sql)) {

            pstmt.setString(1, "admin");
            pstmt.setString(2, "password");

            try (ResultSet rs = pstmt.executeQuery()) {
                while (rs.next()) {
                    System.out.println("User found: " + rs.getString("username"));
                }
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}