好久没有更新文章了,总觉得心里空空的,最近由于工作的原因,没有来的及及时更新,总感觉应该把学习到的东西做个记录,供大家学习,也供自己复习,温故而知新。今天趁着周末休息时间,把自己最近在公司的做的项目做一个总结。由于是刚入职不久,进公司负责的项目内容也很少,主要还是以学习为主。
一、项目介绍
某银行移动办公系统,简称移动OA,是我进公司参与的第一个项目,主要负责的是java后台接口的开发,该系统涉及iOS,android,pad三个前台页面,后台就是为这三个客户端提供公共的接口,根据业务需要,以json格式传递过来的数据在后台进行处理,然后返回到前台进行展示。我们项目组负责的是OA里面的一个小项目-督办,该项目要实现银行项目申报、催促、进度查看、项目再分解等一些功能。根据页面展示需要,我完成了一下几个接口的开发,其中包括一些常用的查找功能和图片压缩下载。
在介绍接口实现之前,有必要把自己学到的json解析再分析一遍,之前接触啊到的json格式的的字符串数据量很小,但在实际项目中数据量是如此之大,面对如此大的数据量,我也曾迷茫过,怎么解析是个问题,后来在项目经理的帮助和自己的努力下,终于完成了json解析这个工具类的开发,我觉的这个类可以应用到很多项目中,只要是涉及到json的地方都可以。
json解析代码如下:
/** * 将json转化成map * @param json * @return * @date 2017年2月25日 * @return Map<String,Object> * @author 我心自在 */ public static Map<String, Object> json2Map(Object json){ if(json.equals("null")){ return null; } JSONObject object = JSONObject.fromObject(json); Map map = new HashMap(); Iterator it = object.keys(); while (it.hasNext()) { String key = (String)it.next(); String value = object.getString(key); if (JSONUtils.isObject(object.get(key))) { map.put(key, json2Map(value)); } else if (JSONUtils.isArray(object.get(key))) { List list = new ArrayList(); JSONArray jArray = JSONArray.fromObject(value); for (int i = 0; i < jArray.size(); i++) { if(JSONUtils.isObject(jArray.get(i)) ){ list.add(json2Map(jArray.get(i))); }else if ( JSONUtils.isArray(jArray.get(i))){ list.add(json2List(jArray.get(i))); }else { list.add(jArray.get(i)); } } map.put(key, list); } else { map.put(key, ConvertUtil.obj2Str(object.get(key))); } } return map; } //下面是ConvertUtil中的部分代码,下面的方法将Object转化为String
public static String obj2Str(Object obj) {
return obj == null ? null : obj.toString();
}
下面适用于json里面带数组的:
/** * 用于 JSON里面带数组的 * @param json * @return */ public static Map<String, Object> jsonArray2Map(Object json){ // if(StringUtils.startsWith(json, "{") && StringUtils.endsWith(json, "}")){ // json = "["+json+"]"; // } JSONArray jsonArray = JSONArray.fromObject(json); JSONObject object = jsonArray.getJSONObject(0); Map map = new HashMap(); Iterator it = object.keys(); while (it.hasNext()) { String key = (String)it.next(); String value = object.getString(key); if (JSONUtils.isObject(object.get(key))) { map.put(key, json2Map(value)); } else if (JSONUtils.isArray(object.get(key))) { List list = new ArrayList(); JSONArray jArray = JSONArray.fromObject(value); for (int i = 0; i < jArray.size(); i++) { if(JSONUtils.isObject(jArray.get(i)) ){ list.add(json2Map(jArray.get(i))); }else if ( JSONUtils.isArray(jArray.get(i))){ list.add(json2List(jArray.get(i))); }else { list.add(jArray.get(i)); } } map.put(key, list); } else { map.put(key, ConvertUtil.obj2Str(object.get(key))); } } return map; }
二、接口的开发
2.1 接口一:左侧菜单显示
该接口主要实现的功能是:将json传递过来的数据到展示到前台页面,主要是左侧菜单的三个按钮。
代码如下:
public class LeftMenuListServlet extends HttpServlet { private static final long serialVersionUID = -169633978370129408L; private Logger logger = Logger.getLogger(this.getClass()); private SuperviseService superviseService = (SuperviseService) ApplicationContextProvider.getBean("superviseService"); protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // response.setContentType("application/x-www-form-urlencoded"); response.setContentType("text/html;charset=UTF-8"); request.setCharacterEncoding("UTF-8"); // //获取入参 String loginUserId = ConvertUtil.obj2Str(request.getSession(true).getAttribute(Current.SESSION_KEY_USER_ID)); MDC.put("user", loUserId); MDC.put("sessionid", request.getSession().getId()); MDC.put("starttime", System.currentTimeMillis()); String opCode = "code_0001_0018_0001"; MDC.put("opcode", opCode); ResultJson resultJson = new ResultJson(); try { String json = request.getParameter("json"); if (StringUtils.isBlank(json)) { resultJson.setEc(CurrencyVariable.EC_PARAMETER_EXCEPTION); resultJson.setEm(CurrencyVariable.EM_PARAMETER_EXCEPTION); } else { // 设置入参 Map jsonMap = JsonUtil.json2Map(json); Map dataMap = (Map) jsonMap.get("data"); String bottomTab = (String) dataMap.get("bottomTab"); String headerTab = (String) dataMap.get("headerTab"); Object currentUserId = loginUserId; logger.info("code_0001_0018_0002"); logger.info("\t currentUserId = " + currentUserId); resultJson = superviseService.leftMenulist(opCode, loginUserId, bottomTab,headerTab); resultJson.setOpCode(opCode); } } catch (Exception e) { logger.error("参数异常 ", e); resultJson.setEc(CurrencyVariable.EC_PARAMETER_EXCEPTION); resultJson.setEm(CurrencyVariable.EM_PARAMETER_EXCEPTION); } String newsResultJson = new GsonBuilder().serializeNulls().create().toJson(resultJson); logger.info(opCode + " newsResultJson==" + newsResultJson); response.getOutputStream().write(newsResultJson.getBytes("UTF-8")); //业务逻辑结束。。。 MDC.put("endtime", System.currentTimeMillis());//请求结束后put // logger.info("操作结果:"+resultJson.getEc()); logger.log(SeriousLogger.SERIOUS_LEVEL, "操作结果:" + resultJson.getEc()); } } //service方法如下: @Override public ResultJson leftMenulist(String opCode, String loginId, String bottomTab, String headerTab) { CloseableHttpClient httpClient = getHttpClient(); ResultJson resultJson = new ResultJson(); resultJson.setOpCode(opCode); // resultJson.setData(jsonObject.get("data");); CloseableHttpResponse httpResponse = null; HttpPost post = new HttpPost(SUPERWISE_HOST + LEFT_MENU_LIST_PATH); log.info(post.getURI()); List<NameValuePair> list = new ArrayList<NameValuePair>(); // 封装入参 list.add(new BasicNameValuePair("bottomTab", bottomTab)); list.add(new BasicNameValuePair("loginId", loginId)); list.add(new BasicNameValuePair("headerTab", headerTab)); // 重写ec,em Common.util(httpClient, resultJson, httpResponse, post, list); return resultJson; }
这里解释一下opCode。该项目的设计思想是通过OpCode来访问servlet,提高访问速度,有利于后期项目的维护,具体的配置在web.xml中可见:
首先定义opcode使之指向要访问的servlet如:
//左侧菜单 public static final String code_0001_0001 = "/mobileoa/web/servlet/dd/LeftMListServlet.do";
然后通过反射的方式加载此类
static{ try{ Class<?> c = Class.forName("com.mobileoa.util.ForwardCtrlVariable"); Field[] fields = c.getDeclaredFields(); for (int i = 0; i < fields.length; i++) { String m = Modifier.toString(fields[i].getModifiers()); if (m != null && m.indexOf("final") > -1 && !("map".equals(fields[i].getName()))) { map.put(fields[i].getName(), (String) fields[i].get(String.class)); } } }catch (ClassNotFoundException e){ log.error("ForwardCtrlVariable:",e); }catch (IllegalArgumentException e){ log.error("ForwardCtrlVariable:",e); }catch (IllegalAccessException e){ log.error("ForwardCtrlVariable:",e); }
获得opcode值,从而访问servlet,web.xml中的配置如下:
<servlet> <servlet-name>dubanLeftMenuListServlet</servlet-name> <servlet-class>com.thitect.middletier.mobileoa.web.servlet.dd.LeftMListServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>ddLeftMenuListServlet</servlet-name> <url-pattern>/mobileoa/web/servlet/dd/LeftMListServlet.do</url-pattern> </servlet-mapping>
Common中util方法主要是对http请求进行了封装,关于http请求的实现方法,参见文章:http://www.cnblogs.com/10158wsj/p/6767209.html
public class Common { private static final Logger log = Logger.getLogger(Common.class); static ResultJson util(CloseableHttpClient httpClient, ResultJson resultJson, CloseableHttpResponse httpResponse, HttpPost post, List<NameValuePair> list) { try { UrlEncodedFormEntity uefEntity = new UrlEncodedFormEntity(list, "UTF-8"); post.setEntity(uefEntity); httpResponse = httpClient.execute(post); HttpEntity entity = httpResponse.getEntity(); String s = EntityUtils.toString(entity); JSONObject jsonObject = JSONObject.fromObject(s); log.info(jsonObject); Object result = jsonObject.get("data"); resultJson.setData(result); String ec = (String) jsonObject.get("ec"); if (ec.equals("0001")) { resultJson.setEc(CurrencyVariable.EC_DUBAN_NOEXIST); resultJson.setEm(CurrencyVariable.EM_DUBAN_NOEXIST); } if (ec.equals("0002")) { resultJson.setEc(CurrencyVariable.EC_DUBAN_EXCEED); resultJson.setEm(CurrencyVariable.EM_DUBAN_EXCEED); } if (ec.equals("0003") || ec.equals("0005")) { resultJson.setEc(CurrencyVariable.EC_DUBAN_DBERROR); resultJson.setEm(CurrencyVariable.EC_DUBAN_DBERROR); } if (ec.equals("0004")) { resultJson.setEc(CurrencyVariable.EC_DUBAN_EXCEPTION); resultJson.setEm(CurrencyVariable.EC_DUBAN_EXCEPTION); } EntityUtils.consume(entity); if (ec.equals("0000")) { resultJson.setEc(CurrencyVariable.EC_SUCESS); resultJson.setEm(CurrencyVariable.EM_SUCESS); resultJson.setData(result); } } catch (Exception e) { e.printStackTrace(); resultJson.setEc(CurrencyVariable.EC_RUNTIME_EXCEPTION); resultJson.setEm(CurrencyVariable.EM_RUNTIME_EXCEPTION); } finally { Common.CloseableHttpResponse(httpResponse); Common.CloseableHttpClient(httpClient); } return resultJson; } private static void CloseableHttpResponse(CloseableHttpResponse httpResponse) { if (httpResponse != null) { try { httpResponse.close(); } catch (IOException e) { e.printStackTrace(); } } } private static void CloseableHttpClient(CloseableHttpClient client) { if (client != null) { try { client.close(); } catch (IOException e) { e.printStackTrace(); } } } }
至此,完成了第一个接口的开发,主要的实现就是这样,后面还陆续写了几个这种类型接口的开发,个人认为这几个接口大同小异,没有必要一一罗列,如图所示:
2.2接口二:图片压缩功能
督办项目中,有一些文件信息十一图片的形式给出的,这就要求前端打开的图片的速度要快,用户体验要好,由于之前没有做图片压缩,导致打开图片事件较长且耗费流量,所以为了实现用户体验,有必要对图片做一下压缩,压缩之后以流的方式进行下载,这个方法是写在action中的也就是struts框架。实现代码如下:
/** * 查看流程意见图片 */ public void showNodeOpinionPic(){ String picURL = request.getParameter("pic_url"); log.info("流程框架页面:ProcBaseForm_正文表单:查看流程处理意见图片=" + picURL); String kmURL = this.getKMHttpUrl(); String url=kmURL+picURL; String fdId = getParamFormUrl(url); logger.info("fdId=" + fdId); String loginUserId = this.getUserId(); logger.info("loginUserId=" + loginUserId); InputStream ins = null; BufferedInputStream bis = null; OutputStream out = null; HttpServletResponse response = ServletActionContext.getResponse(); List filePathResultList = oaImageReduceService.getImageList(fdId, url,request); try { if (filePathResultList != null && filePathResultList.size() > 0) { // 下载 Map<String, Object> filePathMap = (Map) filePathResultList.get(0); logger.info("filePathMap===" + filePathMap); String filePath = (String) filePathMap.get("file_path"); if (!filePath.contains(File.separator) && !filePath.contains("/")) { filePath = auditDownloadService.getFileNameByAuditCode( loginUserId, filePath); } logger.info("filePath===" + filePath); if (StringUtils.isNotEmpty(filePath)) { File file = new File(filePath); if (file.exists()) { long p = 0L; long toLength = 0L; long contentLength = 0L; int rangeSwitch = 0; // 0,从头开始的全文下载;1,从某字节开始的下载(bytes=27000-);2,从某字节开始到某字节结束的下载(ex:bytes=27000-39000) long fileLength; String rangBytes = ""; fileLength = file.length(); logger.info("fileLength Value = " + fileLength); ins = new FileInputStream(file); bis = new BufferedInputStream(ins); response.reset(); response.setHeader("Accept-Ranges", "bytes"); String range = request.getHeader("Range"); logger.info("Range's Value = " + range); if (range != null && range.trim().length() > 0 && !"null".equals(range)) { response.setStatus(javax.servlet.http.HttpServletResponse.SC_PARTIAL_CONTENT); rangBytes = range.replaceAll("bytes=", ""); if (rangBytes.endsWith("-")) { // bytes=270000- rangeSwitch = 1; p = Long.parseLong(rangBytes.substring(0, rangBytes.indexOf("-"))); contentLength = fileLength - p; // 客户端请求的是270000之后的字节(包括bytes下标索引为270000的字节) } else { // bytes=270000-320000 rangeSwitch = 2; String temp1 = rangBytes.substring(0, rangBytes.indexOf("-")); String temp2 = rangBytes.substring( rangBytes.indexOf("-") + 1, rangBytes.length()); p = Long.parseLong(temp1); toLength = Long.parseLong(temp2); contentLength = toLength - p + 1; // 客户端请求的是270000-320000之间的字节 } } else { contentLength = fileLength; } // 如果设设置了Content-Length,则客户端会自动进行多线程下载。如果不希望支持多线程,则不要设置这个参数。 // Content-Length: [文件的总大小] - [客户端请求的下载的文件块的开始字节] //response.setHeader("Content-Length",new Long(contentLength).toString()); // 断点开始 // 响应的格式是: // Content-Range: bytes [文件块的开始字节]-[文件的总大小 - 1]/[文件的总大小] if (rangeSwitch == 1) { String contentRange = new StringBuffer("bytes ") .append(new Long(p).toString()).append("-") .append(new Long(fileLength - 1).toString()) .append("/") .append(new Long(fileLength).toString()) .toString(); response.setHeader("Content-Range", contentRange); bis.skip(p); } else if (rangeSwitch == 2) { String contentRange = range.replace("=", " ") + "/" + new Long(fileLength).toString(); response.setHeader("Content-Range", contentRange); bis.skip(p); } else { String contentRange = new StringBuffer("bytes ") .append("0-").append(fileLength - 1) .append("/").append(fileLength).toString(); response.setHeader("Content-Range", contentRange); } String fileName = file.getName(); response.setContentType("application/octet-stream"); response.addHeader("Content-Disposition","attachment;filename=" + fileName); out = response.getOutputStream(); int n = 0; long readLength = 0; int bsize = 1024; byte[] bytes = new byte[bsize]; if (rangeSwitch == 2) { // 针对 bytes=27000-39000 的请求,从27000开始写数据 while (readLength <= contentLength - bsize) { n = bis.read(bytes); readLength += n; out.write(bytes, 0, n); } if (readLength <= contentLength) { n = bis.read(bytes, 0,(int) (contentLength - readLength)); out.write(bytes, 0, n); } } else { while ((n = bis.read(bytes)) != -1) { out.write(bytes, 0, n); } } } else { logger.info("文件不存在!"); } } } } catch (NumberFormatException e) { e.printStackTrace(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } // 业务处理结束 if (bis != null) { try { bis.close(); } catch (Exception e2) { } } if (ins != null) { try { ins.close(); } catch (Exception e2) { } } if (out != null) { try { out.flush(); out.close(); } catch (Exception e2) { } } } /** * 从url中获取fdId */ private static String getParamFormUrl(String url) { String fdId = ""; if (StringUtils.isEmpty(url)) { fdId = null; } String[] urlArr = url.split("\\?"); if (urlArr == null || urlArr.length == 0) { fdId = null; } for (int i = 0; i < urlArr.length; i++) { if (urlArr[i].contains("FCheckbox=")) { String[] params = urlArr[i].split("\\/"); for (int j = 0; j < params.length; j++) { if (params[j].endsWith(".jpg")) { fdId = params[j].replace(".jpg", ""); } } } } return fdId; } //service部分代码 @Override @Transactional public List getImageList(String fdId, String url, HttpServletRequest request) { logger.info("services param[fdId="+ fdId + ", url=" + url+ "]"); List markList = fileDao.findFileByExtendMark(fdId); logger.info("markList="+ markList); byte[] fileByte = null; String fileNameTemp = null; if(markList == null || markList.size() == 0){ fileByte = this.getImageFromURLNew1(url); fileNameTemp = this.getNewPicName(fileByte, url); logger.info("生成图片名称"+fileNameTemp); } else { fileNameTemp = (String)((Map)markList.get(0)).get("file_path"); logger.info("从数据库获取图片信息:" + fileNameTemp); } List list = fileDao.findChildFileNameByFileName(fileNameTemp, "source"); logger.info("fileDao.findChildFileNameByFileName(fileNameTemp, 'source')"+list); if (list == null || list.size() == 0) { list = postfixFileConvertService.postfixConvert(fileNameTemp, CurrencyVariable.FILE_TYPE_SOURCE_TO_IMAGE, true, fileByte, null, null, request, CurrencyVariable.PORTAL, fdId); } else { list = postfixFileConvertService.postfixConvert(fileNameTemp, CurrencyVariable.FILE_TYPE_SOURCE_TO_IMAGE, true, null, null, null, request, CurrencyVariable.PORTAL, fdId); } return list; }
这段代码基本完成了图片压缩功能的实现,另外通过设置http请求告诉浏览器以流的方式下载图片并显示到前台页页面。
三、总结
这是从学校毕业毕业工作以来,真正意义上接触到的企业大项目,该项目主要的架构就是Spring+Struts+Hibernate,另外还有部分业务的实现用的是Servlet,其实struts本身就是一个大大的Servlet,只不过是更好的对Servlet进行了封装,并且能够更好的实现MVC模式。通过该项目,大大的增加了企业项目的开发经验,熟悉了很多开发工具的使用,本项目采用的是Spring-tools-suitIDE,目的是能够更好的使用Spring。熟悉了代码管理工具SVN的使用,进一步熟悉了开发服务器Weblogic的使用,在linux环境下部署、开发javaWEB项目。
写这篇博文的目的就是及时把自己的项目经验写出来与大家共勉,也为增加自己的开发经验,进一步熟悉企业项目的开发流程,开发特点。
来源:https://www.cnblogs.com/10158wsj/p/7044789.html