通過URL接口定時讀取其返回的xml（可存入數據庫）

之前都是直接讀取xml文件的，可是這次做東西對方只提供一個URL返回xml，我需要定時讀取。
解決方案：
1：通過URL和URLConnection來解析改URL，使其返回inputstream
2：用dom4j解析該inputstream，將解析的數據封裝成需要的對象，來存入一個List或Map
3：定義一個Controller來執行該過程
4：用crontab來執行定時任務（linux下，執行crontab -e進行編輯）

    @Get("/load")  
        public String loadDataFromXmlByDate(Invocation inv, @Param("begin") Date datebegin,  
                @Param("end") Date dateend) {  
            String begin = DateTimeUtil.getFormatDateTime(datebegin, "yyyyMMdd");  
            String end = DateTimeUtil.getFormatDateTime(dateend, "yyyyMMdd");  
    //      String ip = inv.getRequest().getRemoteAddr();  
            String URL = WbConstant.URL + WbConstant.URL_DATE_BEGIN + begin  
                    + WbConstant.URL_DATE_END + end;  
            List<Statistic> stats = parseXML(URL);  
            for (int i = 0; i < stats.size(); i++) {  
                Statistic st = stats.get(i);  
                st.setTime(datebegin);  
                //通過service層來執行邏輯並存儲到DB  
                IResult result = dataService.createStatistic(st);  
                if (result.isSuccess()) {  
                    if (logger.isInfoEnabled()) {  
                        logger.info("insert data into db from xml success");  
                    }  
                } else {  
                    if (logger.isInfoEnabled()) {  
                        logger.info(result.getResult("error").toString());  
                    }  
                }  
            }  
            return "ok";  
        }  
        /** 
         * 加載默認日期的xml 
         * @param inv 
         * @return 
         */  
        @Get("/loadDefault")  
        public String defaultLoadDateFromXml(Invocation inv) {  
            Date today = new Date();  
            Calendar cal = Calendar.getInstance();  
            cal.add(Calendar.DATE, -1);  
            Date yesterday = cal.getTime();  
            return loadDataFromXmlByDate(inv, yesterday, today);  
        }  

        private List<Statistic> parseXML(String URL) {  
            long beginTime = System.currentTimeMillis();  
            List<Statistic> xmlList = new ArrayList<Statistic>();  
            SAXReader reader = new SAXReader();  
            URL url = null;  
            try {  
                url = new URL(URL);  
            } catch (MalformedURLException e) {  
                logger.error("給定的URL生成錯誤", e);  
            }  
            try {  
                URLConnection urlConnection = url.openConnection();  
                InputStream urlIn = urlConnection.getInputStream();  
                doc = reader.read(urlIn);  
            } catch (IOException e) {  
                logger.error("IOException:通過URL-openConnection-getInputStream時，錯誤",  
                        e);  
            } catch (DocumentException e) {  
                logger.error("DocumentExcepion:SAXReader解析inputsream爲Document時，錯誤",  
                        e);  
            }  
            Element root = doc.getRootElement();  
            for (Iterator<Element> it = root.elementIterator(); it.hasNext();) {  
                Element e = (Element) it.next();  
                String date = e.elementText("date");  
                String pid = e.elementText("pid");  
                String data = e.elementText("data");  
                //封裝數據爲對象  
                Statistic stat = new Statistic();  
                stat.setHomeCount(Integer.parseInt(data));  
                stat.setPid(pid);  
                stat.setTime(DateTimeUtil.getFormatDate(date));  
                xmlList.add(stat);  
            }  
            long endTime = System.currentTimeMillis();  
            System.out.println("共花費時間爲" + (endTime - beginTime) + "ms");  
            return xmlList;  
        }  

上面的controller寫完了，就可以用crontab來執行定時任務了，該controllerURL爲,xxx.com/loadDefault則，定爲每天下午2點鐘執行一次如下
00 14 * * * wget -a /data/logs/wb/xml.log http://xxx.com/loadDefault
OK了，可以了