如何为我的Android请求添加md5校验和

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MD5Utils {
    public static String md5(String input) {
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            byte[] messageDigest = md.digest(input.getBytes());
            StringBuilder sb = new StringBuilder();
            for (byte b : messageDigest) {
                sb.append(String.format("%02x", b));
            }
            return sb.toString();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
            return null;
        }
    }
}

public class RequestUtils {
    private static final String SECRET_KEY = "your_secret_key";

    public static String addMD5Checksum(String requestParams) {
        String sortedParams = sortParams(requestParams);
        String checksum = MD5Utils.md5(sortedParams + SECRET_KEY);
        return sortedParams + "&checksum=" + checksum;
    }

    private static String sortParams(String requestParams) {
        // Sort the request parameters according to a certain rule
        // and return the sorted string
    }
}

// Usage example
String requestParams = "param1=value1&param2=value2";
String requestWithChecksum = RequestUtils.addMD5Checksum(requestParams);
// Send the request with the checksum added