Android/feature/src/main/java/ru/ktk45/www/feature/Link.java

package ru.ktk45.www.feature;

import android.os.AsyncTask;
import android.util.Log;

import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;

public class Link extends AsyncTask<String, Void, String> {
    private static final String domain = "http://ktk-45.ru";

    private Map<String, String> parameters = new HashMap<>();

    private String GetParametersString() throws UnsupportedEncodingException {
        StringBuilder result = new StringBuilder();


        for (Map.Entry<String, String> entry : parameters.entrySet()) {
            result.append(URLEncoder.encode(entry.getKey(), "UTF-8"));
            result.append("=");
            result.append(URLEncoder.encode(entry.getValue(), "UTF-8"));
            result.append("&");
        }

        // Считали параметры, больше не нужны, очищаем для следущего запроса
        parameters.clear();

        String resultString = result.toString();
        return resultString.length() > 0
                ? resultString.substring(0, resultString.length() - 1)
                : resultString;
    }

    public JSONObject POST(String url) throws JSONException {

        String result = doInBackground(domain + url);

        if (result.substring(0, 4).equals("Error")) {
            return null;
        }

        JSONObject parser = new JSONObject(result);

        return parser;
    }

    public void SetParameter(String key, String val) {
        parameters.put(key, val);
    }

    @Override
    protected String doInBackground(String... urls) {

        try {
            URL _url = new URL(urls[0]);

            HttpURLConnection connection = (HttpURLConnection)_url.openConnection();
            connection.setRequestMethod("POST");
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
            connection.setRequestProperty("Accept", "application/json, text/javascript, */*; q=0.01");
            connection.setRequestProperty("X-Requested-With", "XMLHttpRequest");
            connection.setRequestProperty("Accept-Encoding", "gzip, deflate");
            connection.setDoOutput(true);
            connection.setDoInput(true);
            connection.setUseCaches(false);
            connection.setConnectTimeout(20000);

            String toWrite = GetParametersString();
            DataOutputStream out = new DataOutputStream(connection.getOutputStream());
            out.writeBytes(toWrite);
            out.flush();
            out.close();

            connection.connect();

            BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String inputLine;
            StringBuffer content = new StringBuffer();
            while ((inputLine = in.readLine()) != null) {
                content.append(inputLine);
            }
            in.close();

            connection.disconnect();

            return content.toString();

        } catch (IOException e) {
            return "Error: " + e.getMessage();
        }
    }
    // onPostExecute displays the results of the AsyncTask.
    @Override
    protected void onPostExecute(String result) {
        Log.i("INFO", result);
    }
}