java开发中常用到小方法

ArrayList转数组

  /*
   * 获取优惠券全部策略ID String[]
   */
  private String[] getStrategyIDArrayCache() throws Exception {
    ArrayList<String> list = new ArrayList<String>();
    String[] strArray = new String[] {};
    int RightsType = BusinessEmun.RightsType.优惠券.getValue();
    List<McRights> resultList = cacheManagement.rightsListCache.getData(RightsType);

    if (resultList != null && resultList.size() > 0) {
      for (McRights mcRights : resultList) {
        list.add(mcRights.getStrategyID());
      }

      if (list.size() > 0) {
        strArray = (String[]) list.toArray(new String[0]);
      }
    }

    return strArray;
  }

验证是否在String[] arr范围内

  /**
   * 验证是否在String[] arr范围内
   *
   * @Title: IsContains
   * @Description: TODO
   * @param
   * @return
   * @throws
   */
  private boolean isContains(String[] arr, String targetValue) {
    int a = Arrays.binarySearch(arr, targetValue);
    if (a >= 0)
      return true;
    else
      return false;
  }

根据属性名获取属性值

   /**
     * @Title: getFieldValueByName
     * @Description: 根据属性名获取属性值
     * @param obj：需要查找的对象，fieldName：对象属性
     * @return 得到结果对象
     * @throws
     */
    private  Object getFieldValueByName(Object obj, String fieldName) {
        try {
            String firstLetter = fieldName.substring(0, 1).toUpperCase();
            String getter = "get" + firstLetter + fieldName.substring(1);
            Method method = obj.getClass().getMethod(getter, new Class[]{});
            Object value = method.invoke(obj, new Object[]{});
            return value;
        } catch (Exception e) {
            Logger.error("getFieldValueByName异常", e);
            return null;
        }
    }