String params = "{\"prefixText\":\"aCity\",\"count\":10,\"contextKey\":\"he\"}";
conn = (HttpURLConnection) new URL("http://bus.gov.il/WebForms/wfrmMain.aspx/GetCompletionList").openConnection();
conn.setDoOutput(true);
conn.setRequestMethod("POST");
conn.setFixedLengthStreamingMode(params.length());
conn.addRequestProperty("Content-Type", "application/json; charset=UTF-8");
conn.addRequestProperty("Referer", "http://bus.gov.il/WebForms/wfrmMain.aspx?width=1024&company=1&language=he&state=");
Writer out = new BufferedWriter(new OutputStreamWriter(conn.getOutputStream()));
out.write(params);
out.close();
String answer = readStream(conn.getInputStream(), "utf-8");