Android开发实现查询远程服务器的工具类QueryUtils完整实例

/**
 * 查询远程服务器的工具
 * @author chen.lin
 *
 */
public class QueryUtils {
  private static final String TAG = "CommonUtils";
  private static QueryUtils instance;
  private SharedPreferences sp;
  private QueryUtils(Context context){
    sp = context.getSharedPreferences(Constant.CONFIG, Context.MODE_PRIVATE);
  }
  public static QueryUtils getInstance(Context context){
    if (instance == null) {
      synchronized (QueryUtils.class) {
        if (instance == null) {
          instance = new QueryUtils(context);
        }
      }
    }
    return instance;
  }
  /**
   * 请求服务器得到返回值
   *
   * @param keyword
   * @return
   * @throws Exception
   */
  public String getValue(String keyword, String reqType) throws Exception {
    String returnValue = null;
    // 使用Map封装请求参数
    Map<String, String> map = new HashMap<String, String>();
    map.put("reqType", reqType);
    map.put("localIP", sp.getString(Constant.NETIP, ""));
    if (keyword != null && !"".equals(keyword)) {
      map.put("keyword", keyword);
    }
    String url = "http://" + sp.getString(Constant.NETURL, "") + "/ymerp/" + "ServiceDocumentServlet";
    returnValue = HttpUtil.postRequest(url, map);
    return returnValue;
  }
  /**
   * 请求服务器得到返回值
   *
   * @param keyword
   * @return
   * @throws Exception
   */
  public String queryServer(String keyword, String reqType, String servlet) throws Exception {
    String returnValue = null;
    // 使用Map封装请求参数
    Map<String, String> map = new HashMap<String, String>();
    map.put("reqType", reqType);
    map.put("localIP", sp.getString(Constant.NETIP, ""));
    if (!TextUtils.isEmpty(keyword)) {
      map.put("keyword", keyword);
    }
    String url = "http://" + sp.getString(Constant.NETURL, "") + "/ymerp/" + servlet;
    returnValue = HttpUtil.postRequest(url, map);
    return returnValue;
  }
  /**
   * 将json 数组转换为Map 对象
   *
   * @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 = jsonObject.keys();
      HashMap<String, Object> valueMap = new HashMap<String, Object>();
      while (it.hasNext()) {
        key = (String) it.next();
        value = jsonObject.get(key);
        if (key != null && title.equals(key) && value != null) {
          String valuestr = value.toString();
          if (valuestr.length() > 15) {
            valuestr = valuestr.substring(0, 13) + "...";
            value = valuestr;
          }
        }
        if (key != null && timeStr.equals(key)) {
          try {
            if (value != null) {
              Date date = (Date) value;
              value = yymmdd.format(date);
            } else {
              valueMap.put(key, "");
            }
          } catch (Exception e) {
          }
        }
        if (key != null && value != null) {
          valueMap.put(key, value);
        }
      }
      return valueMap;
    } catch (JSONException e) {
      e.printStackTrace();
    }
    return null;
  }
}