Android development complete example of QueryUtils tool class that implements query remote servers

/**
  * Tools for querying remote servers
  * @author
  *
  */
public class QueryUtils {
  private static final String TAG = "CommonUtils";
  private static QueryUtils instance;
  private SharedPreferences sp;
  private QueryUtils(Context context){
    sp = (, Context.MODE_PRIVATE);
  }
  public static QueryUtils getInstance(Context context){
    if (instance == null) {
      synchronized () {
        if (instance == null) {
          instance = new QueryUtils(context);
        }
      }
    }
    return instance;
  }
  /**
    * The request server gets the return value
    *
    * @param keyword
    * @return
    * @throws Exception
    */
  public String getValue(String keyword, String reqType) throws Exception {
    String returnValue = null;
    // Use Map to encapsulate request parameters    Map<String, String> map = new HashMap<String, String>();
    ("reqType", reqType);
    ("localIP", (, ""));
    if (keyword != null && !"".equals(keyword)) {
      ("keyword", keyword);
    }
    String url = "http://" + (, "") + "/ymerp/" + "ServiceDocumentServlet";
    returnValue = (url, map);
    return returnValue;
  }
  /**
    * The request server gets the return value
    *
    * @param keyword
    * @return
    * @throws Exception
    */
  public String queryServer(String keyword, String reqType, String servlet) throws Exception {
    String returnValue = null;
    // Use Map to encapsulate request parameters    Map<String, String> map = new HashMap<String, String>();
    ("reqType", reqType);
    ("localIP", (, ""));
    if (!(keyword)) {
      ("keyword", keyword);
    }
    String url = "http://" + (, "") + "/ymerp/" + servlet;
    returnValue = (url, map);
    return returnValue;
  }
  /**
    * Convert json array to Map object
    *
    * @param jsonString
    * @return
    */
  @SuppressLint("SimpleDateFormat")
  public static HashMap<String, Object> getMap(String jsonStr, String title, String timeStr) {
    SimpleDateFormat yymmdd = new SimpleDateFormat("yyyy-MM-dd");
    JSONObject jsonObject = null;
    String key = null;
    Object value = null;
    try {
      jsonObject = new JSONObject(jsonStr);
      Iterator<String> it = ();
      HashMap<String, Object> valueMap = new HashMap<String, Object>();
      while (()) {
        key = (String) ();
        value = (key);
        if (key != null && (key) && value != null) {
          String valuestr = ();
          if (() > 15) {
            valuestr = (0, 13) + "...";
            value = valuestr;
          }
        }
        if (key != null && (key)) {
          try {
            if (value != null) {
              Date date = (Date) value;
              value = (date);
            } else {
              (key, "");
            }
          } catch (Exception e) {
          }
        }
        if (key != null && value != null) {
          (key, value);
        }
      }
      return valueMap;
    } catch (JSONException e) {
      ();
    }
    return null;
  }
}