/**
     * 獲取用戶真實IP
     * 如果有代理，獲取真實客戶端IP
     * @param request
     * @return
     */
    public  static  String getRealId(HttpServletRequest request){

        String xForwardedForHeader= request.getHeader("X-Forwarded-For");
        if(xForwardedForHeader == null){
            return  request.getRemoteAddr();

        }else {
            return  new StringTokenizer(xForwardedForHeader, ",").nextToken().trim();
        }

    }

 
/**
     * 使用java反射機制，動態獲取對象的屬性和參數值，排除值為null的情況，并按字典序排序
     * @param object
     * @return
     */
    public static   String getSortMap(Object object) throws  Exception{
        //1.得到屬性的名稱及值 如果為null不存入map
        Field [] fields = object.getClass().getDeclaredFields();
        Map<String,String> map = new HashMap<>();
        for(Field field : fields){
            String name = field.getName();
            /*String methodName = "get"+name.replaceFirst(name.substring(0, 1), name.substring(0, 1)
                    .toUpperCase());*/
            //通過get方法直接獲取屬性值
            field.setAccessible(true);
            Object value = field.get(object);
            if (value != null){
                map.put(name, value.toString());
            }


        }
        //排序
        Map<String, String> sortMap = new TreeMap<String,String>(
                new Comparator<String>() {

                    @Override
                    public int compare(String arg0, String arg1) {

                        return arg0.compareTo(arg1);
                    }
                });
        sortMap.putAll(map);


        StringBuilder sortFeil = new StringBuilder();
        //得到鍵值對的格式（即key1=value1&key2=value2…
        sortMap.forEach((k,v)-> {
            sortFeil.append(k+"="+v+"&");
        });
        //移除最后一個 &
        sortFeil.deleteCharAt(sortFeil.length()-1);
        return sortFeil.toString();

    }

/**
 * 微信統一下單請求對象
 *
 * @Author xuelongjiang
 */
@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name = "xml")//xml的根元素
public class WechatUnifiedorderRequest  implements Serializable{
}
對象轉換為xml字符
引入包：import javax.xml.bind.JAXBContext

 /**
     * 對象轉換為xml
     * @param object
     * @return
     */
    public static  String objectToXml(Object object){

        StringWriter sw = new StringWriter();
        try {

            JAXBContext context = JAXBContext.newInstance(object.getClass());
            Marshaller marshaller =  context.createMarshaller();
            marshaller.marshal(object,sw);

        }catch (Exception e){
            e.printStackTrace();
            logger.error("對象解析xml出現異常，對象為"+object.toString());
        }

        return sw.toString();
    }

<xml>
   <return_code><![CDATA[SUCCESS]]></return_code>
   <return_msg><![CDATA[OK]]></return_msg>
   <appid><![CDATA[wx2421b1c4370ec43b]]></appid>
   <sub_appid><![CDATA[wx2421b1c4370ec11b]]></sub_appid>
   <mch_id><![CDATA[10000100]]></mch_id>
   <sub_mch_id>![CDATA[10000101]]></appid>
   <nonce_str><![CDATA[IITRi8Iabbblz1Jc]]></nonce_str>
   <sign><![CDATA[7921E432F65EB8ED0CE9755F0E86D72F]]></sign>
   <result_code><![CDATA[SUCCESS]]></result_code>
   <prepay_id><![CDATA[wx201411101639507cbf6ffd8b0779950874]]></prepay_id>
   <trade_type><![CDATA[JSAPI]]></trade_type>
</xml>

/**
 *
 * 注解使用， 對象與xml轉換的字段需要有 <![CDATA[]]>
 *
 * @Author xuelongjiang
 */
public class CDataAdapter extends XmlAdapter<String,String> {

    private static Logger logger = LoggerFactory.getLogger(CDataAdapter.class);

    /**
     * Do-nothing constructor for the derived classes.
     */
    protected CDataAdapter() {
        super();
    }

    /**
     * Convert a value type to a bound type.
     *
     * @param v The value to be converted. Can be null.
     * @throws Exception if there's an error during the conversion. The caller is responsible for
     *                   reporting the error to the user through {@link ValidationEventHandler}.
     */
    @Override
    public String unmarshal(String v) throws Exception {

      if("<![CDATA[]]>".equals(v)){
          return "";
      }
      String v1 = null;
      String v2 = null;

      String subStart = "<![CDATA[";
      int a = v.indexOf(subStart);
      if(a>= 0){
          v1 = v.substring(subStart.length(),v.length());

      }else {
          return v;
      }
      String subEnd = "]]>";
      int b = v1.indexOf(subEnd);
      if(b>= 0){
          v2 = v1.substring(0,b);
      }
      return v2;

    }

    /**
     * Convert a bound type to a value type.
     *
     * @param v The value to be convereted. Can be null.
     * @throws Exception if there's an error during the conversion. The caller is responsible for
     *                   reporting the error to the user through {@link ValidationEventHandler}.
     */
    @Override
    public String marshal(String v) throws Exception {

        logger.info("對象轉換xml:"+"<![CDATA["+ v +"]]>");
        return "<![CDATA["+ v +"]]>";
    }
}