通过URL接口定时读取其返回的xml（可存入数据库）

之前都是直接读取xml文件的，可是这次做东西对方只提供一个URL返回xml，我需要定时读取。
解决方案：
1：通过URL和URLConnection来解析改URL，使其返回inputstream
2：用dom4j解析该inputstream，将解析的数据封装成需要的对象，来存入一个List或Map
3：定义一个Controller来执行该过程
4：用crontab来执行定时任务（linux下，执行crontab -e进行编辑）

    @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);  
                //通过service层来执行逻辑并存储到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";  
        }  
        /** 
         * 加载默认日期的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("给定的URL生成错误", e);  
            }  
            try {  
                URLConnection urlConnection = url.openConnection();  
                InputStream urlIn = urlConnection.getInputStream();  
                doc = reader.read(urlIn);  
            } catch (IOException e) {  
                logger.error("IOException:通过URL-openConnection-getInputStream时，错误",  
                        e);  
            } catch (DocumentException e) {  
                logger.error("DocumentExcepion:SAXReader解析inputsream为Document时，错误",  
                        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");  
                //封装数据为对象  
                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("共花费时间为" + (endTime - beginTime) + "ms");  
            return xmlList;  
        }  

上面的controller写完了，就可以用crontab来执行定时任务了，该controllerURL为,xxx.com/loadDefault则，定为每天下午2点钟执行一次如下
00 14 * * * wget -a /data/logs/wb/xml.log http://xxx.com/loadDefault
OK了，可以了