struts 获取request

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当初没有添加获取request的代码，所以总是反应空指针异常

下面我就给出一个实例程序来演示如何处理有多个submit的form：

【第1步】实现主页面(more_submit.jsp)

<%@page language="java" import="java.util.*" pageEncoding="utf-8"%><%@ taglib prefix="s" uri="/struts-tags"%><html><head>　<title></title></head><body>　<s:form action="submit.action" ><s:textfield name="msg" label="请输入内容"></s:textfield><s:submit name="save" method="save" value="保存"/> 　      <s:submit name="print" method="print" value="打印" /> 　</s:form>　</body>　</html>

在more_submit.jsp中有两个submit：保存和打印。其中分别通过method属性指定了要调用的方法：save和print。因此，在Action类中必须要有save和print方法。

【第2步】实现Action类（MoreSubmitAction）

package action;import javax.servlet.http.HttpServletRequest;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionContext;import com.opensymphony.xwork2.ActionSupport;public class FirstAction extends ActionSupport {private String msg;public String getMsg() {return msg;}public void setMsg(String msg) {this.msg = msg;}// 处理savesubmit按钮动作public String save() throws Exception {HttpServletRequest request=ServletActionContext.getRequest();  request.setAttribute("result", "成功保存[" + msg + "]");return "save";}// 处理printsubmit按钮动作public String print() throws Exception {HttpServletRequest request=ServletActionContext.getRequest(); request.setAttribute("result", "成功打印["+msg+"]");return "print";}}

【第3步】配置Struts2 Action

struts.xml的代码如下：

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE struts PUBLIC    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"    "http://struts.apache.org/dtds/struts-2.0.dtd">    <struts><package name="demo" extends="struts-default"><action name="submit" class="action.FirstAction">  <result name="save">/result.jsp</result>  <result name="print">/result.jsp</result></action></package></struts>

【第4步】编写结果页（result.jsp）

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <base href="<%=basePath%>">        <title>My JSP 'result.jsp' starting page</title>    <meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0">    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"><!--<link rel="stylesheet" type="text/css" href="styles.css">-->  </head>    <body>    <h1>${result }</h1>  </body></html>