学习笔记归纳 2010-9-5.1-9

1. import org.apache.commons.beanutils.BeanUtils; //将页面表单提交来的数据注入到action中的属性上。 BeanUtils.populate(action, req.getParameterMap()); 处理表单提交过来的数据，但不可以处理时间类型的数据，要特殊处理 2. import org.apache.commons.beanutils.ConvertUtils; // 注册一个类型转换器 ConvertUtils.register(new DataTypeConvert(), java.util.Date.class); 处理时间数据 import java.text.ParseException; import java.text.SimpleDateFormat; import org.apache.commons.beanutils.Converter; public class DataTypeConvert implements Converter { public Object convert(Class arg0, Object arg1) { Object value = null; if (arg0 == java.util.Date.class) { try { SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); value = sdf.parse((String) arg1); } catch (ParseException e) { e.printStackTrace(); } } return value; } } 3. 文件上传和处理文件的编码方式 //文件上传 表单所有的数据 又分为两块 一个普通数据 另一个数据为文件类型的数据 //如果为普通数据isFormField为TRUE则做普通数据处理 为FALSE则作为文件数据处理 //编码有三个地方 第一是页面里的charset=utf-8 第二是表单提交的enctype="multipart/form-data"，application/x-www-form-urlencoded，text/plain //第三是过滤器的编码方式request.setCharacterEncoding(encoding); String contentType = req.getContentType(); if (contentType != null && contentType.startsWith("multipart/form-data")) { // multipart/form-data文件方式提交数据 doFileUpload(req, action); ServletFileUpload fileUpload = new ServletFileUpload( new DiskFileItemFactory()); try { List<FileItem> list = fileUpload.parseRequest(req); for (FileItem item : list) { try { if (item.isFormField()) { // 如果为普通的input表单元素，直接将值注入到Action中 String oldValue = item.getString(); String encoding = req.getCharacterEncoding(); if(encoding == null || encoding.equals("")){ encoding = "utf-8"; } // 因为过滤器可能有设置，尽量使用过滤器的编码方式，如果没有，使用缺省的编码方式 String newValue = new String(oldValue .getBytes("iso8859-1"), encoding); BeanUtils.copyProperty(action, item.getFieldName(), newValue); } else { // 如果是文件类型的输入框，先判断是否有文件上传 if (item.getName() == null || item.getName().equals("")) { continue; } // 如果有文件上传，把它保存到tomcat的临时目录中去。 String fileName = String.format("%s//%s.tmp", System.getProperty("java.io.tmpdir"), new Random().nextLong()); File file = new File(fileName); item.write(file); // 把临时目录的文件对象注入到action中，让action能对他灵活操作。 BeanUtils.copyProperty(action, item.getFieldName(), file); // 将客户端的原始文件名也传递到action中 BeanUtils.copyProperty(action, item.getFieldName() + "FileName", item.getName()); } } catch (IllegalAccessException e) { } catch (InvocationTargetException e) { } catch (Exception e) { } } } catch (FileUploadException e) { e.printStackTrace(); } 4. 过滤器 文件编码过滤器和录入过滤器 //配置编码过滤器 <filter> <filter-name>SetCharacterEncoding</filter-name> <filter-class>com.softeem.blog.filter.SetCharacterEncoding</filter-class> <init-param> <param-name>encoding</param-name> <param-value>UTF-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>SetCharacterEncoding</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> public class CharacterEncodingFilter implements Filter { String encoding; public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2) throws IOException, ServletException { HttpServletRequest request=(HttpServletRequest)arg0; request.setCharacterEncoding(encoding); arg2.doFilter(arg0, arg1); //放行 } public void init(FilterConfig arg0) throws ServletException { this.encoding=arg0.getInitParameter("encoding"); } //配置录入过滤器 <filter> <filter-name>LoginFilter</filter-name> <filter-class>com.softeem.blog.filter.LoginFilter</filter-class> <init-param> <param-name>except</param-name> <param-value>login.jsp,login.action,user_list.action</param-value> </init-param> </filter> <filter-mapping> <filter-name>LoginFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> public class LoginFilter implements Filter { String excepts; public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2) throws IOException, ServletException { HttpServletRequest request=(HttpServletRequest)arg0; HttpServletResponse response=(HttpServletResponse)arg1; //--------URI=/blog/article_list.action String uri=request.getRequestURI(); String cmd=uri.substring(uri.lastIndexOf("/")+1); String[] ex=excepts.split(","); for(String except:ex){ if(except.equalsIgnoreCase(cmd)){ arg2.doFilter(request, response); return; } } Object obj=request.getSession().getAttribute("USER"); if(obj==null){ response.sendRedirect("login.jsp"); return; } arg2.doFilter(request, response); //放行 } public void init(FilterConfig filterConfig) throws ServletException { excepts=filterConfig.getInitParameter("except"); } } 5. // 读配置文件struts.xml 在init（）方法里读 InputStream in = this.getServletContext().getResourceAsStream("/WEB-INF/classes/struts.xml"); 6．用dom4j解析struts.xml // Map<String, ActionConfig> maps = new HashMap<String, ActionConfig>(); 用来保存解析好的strust.xml里的值 反射所需要的值 import org.dom4j.Document; import org.dom4j.Element; import org.dom4j.io.SAXReader; SAXReader reader = new SAXReader(); Document document = reader.read(in); List<Element> actions = document.selectNodes("/struts/package/action"); for(Element element : actions){ String methodName = element.attributeValue("method"); if(StringUtils.isEmpty(methodName)){ methodName="execute"; } ActionConfig aconfig = new ActionConfig( element.attributeValue("class"), methodName, element.attributeValue("name")); //// ActionConfig的属性是 ////String className; ////String methodName; ////Map<String, ResultConfig> results = new HashMap<String, ResultConfig>(); ////String uriName; List<Element> results = element.selectNodes("result"); for(Element result : results){ String name = result.attributeValue("name"); if(StringUtils.isEmpty(name)){ name = "success"; } ResultConfig rconfig = new ResultConfig( name, result.attributeValue("type"), result.getText());
//// ResultConfig的属性是 //// String name; //// String type; //// String pageUri; aconfig.getResults().put(name, rconfig); } maps.put(element.attributeValue("name"), aconfig); } 7.我们的action.servlet // 得到URI,根据URI实例化对应的Action String cmd = getURI(req); ActionConfig config = maps.get(cmd); String clzName = config.getClassName(); String methodName = config.getMethodName(); // 实例化Action Action action = getAction(clzName); // 将页面传递过来的值装配到Action中 formAware(req, action); // 将session传递到action中 doAware(req, resp, action); // 在action上面调用它的方法 Object resultName = invokeAction(methodName, action); ResultConfig rConfig = config.getResults().get(resultName); // 把action里的所有属性放置到request中 saveActionProperties(req, action); // 如果跳转页面不为空，根据跳转类型调用跳转方法 String address = rConfig.getPageUri(); if (StringUtils.isNotEmpty(address)) { if ("forward".equals(rConfig.getType())) { req.getRequestDispatcher(address).forward(req, resp); } else { resp.sendRedirect(address); } } 8.需要request的地方可以继承request的接口 session和response /** * 将HttpServletRequest, Httpsession, HttpServletResponse传递到action中 如果action * 没有实现SessionAware, ResponseAware, RequestAware接口 * 就不将request,response,session注入 * * @param req HttpServletRequest * @param response HttpServletResponse * @param action 需要注入3个变量的Action */ private void doAware(HttpServletRequest req, HttpServletResponse response, Action action) { /* 实现了SessionAware接口 */ if (action instanceof SessionAware) { // instanceof 判断a是否是b的实例 SessionAware sa = (SessionAware) action; sa.setHttpSession(req.getSession()); } /* 实现了ResponseAware接口 */ if (action instanceof ResponseAware) { ResponseAware ra = (ResponseAware) action; ra.setResponse(response); } /* 实现了RequestAware接口 */ if (action instanceof RequestAware) { RequestAware ra = (RequestAware) action; ra.setRequest(req); } } 9.适配器action接口；actionsupport实现action 以后所有要实现action的类就可以继承actionsupport； action的强制性被解除 public interface Action { String execute(); } public class ActionSupport implements Action { public String execute() { return null; } }