安卓mysql注册登录

// 示例代码：连接MySQL数据库
String url = "jdbc:mysql://your_server_address:3306/your_database";
String user = "your_username";
String password = "your_password";

try {
    Connection conn = DriverManager.getConnection(url, user, password);
    System.out.println("连接成功");
} catch (SQLException e) {
    System.out.println("连接失败: " + e.getMessage());
}

// 示例代码：使用PreparedStatement防止SQL注入
String sql = "SELECT * FROM users WHERE username = ? AND password = ?";
try (Connection conn = DriverManager.getConnection(url, user, password);
     PreparedStatement pstmt = conn.prepareStatement(sql)) {
    pstmt.setString(1, username);
    pstmt.setString(2, password);
    ResultSet rs = pstmt.executeQuery();
    if (rs.next()) {
        System.out.println("登录成功");
    } else {
        System.out.println("登录失败");
    }
} catch (SQLException e) {
    System.out.println("查询失败: " + e.getMessage());
}

// 示例代码：使用SHA-256对密码进行加密
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public String encryptPassword(String password) {
    try {
        MessageDigest md = MessageDigest.getInstance("SHA-256");
        byte[] hash = md.digest(password.getBytes());
        StringBuilder sb = new StringBuilder();
        for (byte b : hash) {
            sb.append(String.format("%02x", b));
        }
        return sb.toString();
    } catch (NoSuchAlgorithmException e) {
        throw new RuntimeException("加密失败", e);
    }
}