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;        }    }