Android ServiceHandler using HttpURLConnection

ServiceHandler.java

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;

public class ServiceHandler {

    public final static int GET = 1;
    public final static int POST = 2;
    public final static int PUT = 3;
    public final static int DELETE = 4;
    public final static int PATCH = 5;
    public static int STATUS_CODE = 0;
    Activity mActivity;
    StringBuilder sbResponse;

    public ServiceHandler() {
    }

    public String makeServiceCall(String stringUrl, int method, String urlParameters, Activity activity,
                                  boolean isJsonRequest) {
        this.mActivity = activity;
        HttpURLConnection httpURLConnection = null;
        try {
            if (method == GET) {
                if (urlParameters != null) {
                    stringUrl = stringUrl + "?" + urlParameters;
                }
                URL url = new URL(stringUrl);
                httpURLConnection = (HttpURLConnection) url.openConnection();
                httpURLConnection.setUseCaches(false);
                httpURLConnection.setAllowUserInteraction(false);
                httpURLConnection.setConnectTimeout(0);
                httpURLConnection.setReadTimeout(0);
                httpURLConnection.setRequestMethod("GET");
                httpURLConnection.setDoOutput(false);
                httpURLConnection.connect();

            } else if (method == POST) {
                URL url = new URL(stringUrl);
                httpURLConnection = (HttpURLConnection) url.openConnection();
                httpURLConnection.setUseCaches(false);
                httpURLConnection.setAllowUserInteraction(false);
                httpURLConnection.setConnectTimeout(0);
                httpURLConnection.setReadTimeout(0);
                httpURLConnection.setRequestMethod("POST");
                httpURLConnection.setDoOutput(true);
                if (urlParameters != null) {
                    if (isJsonRequest) {
                        httpURLConnection.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
                    } else {
                        httpURLConnection.setRequestProperty("Content-type", "application/x-www-form-urlencoded");
                    }
                    httpURLConnection.connect();
                    OutputStream os = httpURLConnection.getOutputStream();
                    BufferedWriter writer = new BufferedWriter(
                            new OutputStreamWriter(os, "UTF-8"));
                    writer.write(urlParameters);
                    writer.flush();
                    writer.close();
                    os.close();
                }
            }
            BufferedReader br = new BufferedReader(new InputStreamReader(httpURLConnection.getInputStream()));
            sbResponse = new StringBuilder();
            String line;
            while ((line = br.readLine()) != null) {
                sbResponse.append(line + "\n");
            }
            br.close();
            STATUS_CODE = httpURLConnection.getResponseCode();
        } catch (Exception ex) {
            ex.printStackTrace();
            try {
                STATUS_CODE = httpURLConnection.getResponseCode();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        httpURLConnection.disconnect();
        return sbResponse.toString();
    }
}