Struts 1.3.8 Action实现类中消息的输出及JSP页面中消息标签的使用总结

(1) Action中保存消息及错误的简单实现： …… //此处是ActionMessages是带’s’的类名 ActionMessages messages = new ActionMessages(); //向messages添加一个消息对象，并设定property为“sucess” messages.add(“sucess”, new ActionMessage(“source.key”)); //将消息集合保存到request中，并以“org.apache.struts.action.ACTION_MESSAGE”为关键字；此方法可在下面看到Action类中实现的源代码 saveMessages(request,messages); //将消息集合保存到request中，并以“org.apache.struts.action.ERROR”为关键字；此方法可在下面看到Action类中实现的源代码 saveErrors(request,messages); …… (2) Struts 1.3.8中的Action中保存消息和错误的源代码如下： protected void addMessages(HttpServletRequest request, ActionMessages messages) { if (messages == null) return; ActionMessages requestMessages = (ActionMessages)request.getAttribute("org.apache.struts.action.ACTION_MESSAGE"); if (requestMessages == null) requestMessages = new ActionMessages(); requestMessages.add(messages); if (requestMessages.isEmpty()) { request.removeAttribute("org.apache.struts.action.ACTION_MESSAGE"); return; } else { request.setAttribute("org.apache.struts.action.ACTION_MESSAGE", requestMessages); return; } } protected void addErrors(HttpServletRequest request, ActionMessages errors) { if (errors == null) return; ActionMessages requestErrors = (ActionMessages)request.getAttribute("org.apache.struts.action.ERROR"); if (requestErrors == null) requestErrors = new ActionMessages(); requestErrors.add(errors); if (requestErrors.isEmpty()) { request.removeAttribute("org.apache.struts.action.ERROR"); return; } else { request.setAttribute("org.apache.struts.action.ERROR", requestErrors); return; } } (3) JSP页面中用和标签输出： …… …… MessagesTag的实现类构造如下： public MessagesTag() { iterator = null; processed = false; id = null; bundle = null; locale = "org.apache.struts.action.LOCALE"; name = "org.apache.struts.action.ERROR"; property = null; header = null; footer = null; message = null; }