Скачать или смотреть 5. Enhance security in the Java backend to protect against common vulnerabilities.

Code:

import java.sql.*;
import java.util.Scanner;

class dbdb3 {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);

String url = "jdbc:mysql://localhost:3306/user_auth"; // your DB name
String username = "root"; // MySQL username
String password = "root"; // MySQL password

try {
System.out.print("Enter username to search: ");
String inputName = sc.nextLine();

// Step 1: Load MySQL driver
Class.forName("com.mysql.cj.jdbc.Driver");

// Step 2: Establish connection
Connection con = DriverManager.getConnection(url, username, password);
System.out.println("\n✅ Connection Established Successfully!");

// Step 3: Prepare SQL query
String query = "SELECT * FROM users WHERE name = ?";
PreparedStatement pst = con.prepareStatement(query);
pst.setString(1, inputName);

// Step 4: Execute query
ResultSet rs = pst.executeQuery();

// Step 5: Display result
if (rs.next()) {
int id = rs.getInt("id");
String name = rs.getString("name");
String email = rs.getString("email");
String pass = rs.getString("password");

System.out.println("\nUser Found:");
System.out.println("ID: " + id + " | Name: " + name + " | Email: " + email + " | Password: " + pass);
} else {
System.out.println("\n❌ No user found with name: " + inputName);
}

// Step 6: Close connections
rs.close();
pst.close();
con.close();
sc.close();

System.out.println("\n🔒 User Connection Closed Successfully!");

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