首页新闻找找看学习计划

freemarker.core.InvalidReferenceException

0
悬赏园豆:30 [已解决问题] 解决于 2015-04-26 23:37

新手在学struts2,出现了

freemarker.core.InvalidReferenceException: Expression parameters.id is undefined on line 66, column 8 in template/simple/radiomap.ftl.异常,但是我根本就没有有使用过id参数,请问怎么解决啊?

问题补充:

Action动作类:

 1 package cn.itcast.ognl;
 2 
 3 import java.util.Map;
 4 
 5 import javax.servlet.ServletContext;
 6 import javax.servlet.http.HttpServletRequest;
 7 
 8 import org.apache.struts2.ServletActionContext;
 9 
10 import com.opensymphony.xwork2.ActionSupport;
11 import com.opensymphony.xwork2.util.ValueStack;
12 
13 @SuppressWarnings("serial")
14 public class OgnlAction extends ActionSupport {
15     
16     private String name = "oname";
17     
18     private String sex = "male";
19     
20     public String getName() {
21         return name;
22     }
23 
24     public void setName(String name) {
25         this.name = name;
26     }
27 
28     public String getSex() {
29         return sex;
30     }
31 
32     public void setSex(String sex) {
33         this.sex = sex;
34     }
35 
36     public String test(){
37         System.out.println("OgnlAction ************ test()");
38         
39         HttpServletRequest request = ServletActionContext.getRequest();
40         request.setAttribute("username", "username_request");
41         request.setAttribute("password", "password_request");
42         
43         Map sessionMap = ServletActionContext.getContext().getSession();
44         sessionMap.put("username", "username_session");
45         sessionMap.put("password", "password_session");
46         
47         ServletContext sc = ServletActionContext.getServletContext();
48         sc.setAttribute("username", "username_application");
49         sc.setAttribute("password", "password_application");
50         
51         //方法一:获取ValueStack对象
52         ValueStack valueStack1 = (ValueStack)request.getAttribute("struts.valueStack");
53         System.out.println("valueStack = "+valueStack1);
54         
55         /*
56          * 插入的内容,实际上是先放置在一个map集合中,又把这个map集合放置在对象栈里
57          */
58         valueStack1.set("error", "error_valueStack");
59         valueStack1.set("msg", "msg_valueStack");
60         
61         valueStack1.getRoot().add(0, new Person());
62         valueStack1.getRoot().add(0,new Employee());
63         
64         //方法二:获取ValueStack对象
65         /*ValueStack valueStack2 = ServletActionContext.getContext().getValueStack();
66         System.out.println("valueStack = "+valueStack2);*/
67         
68         
69         return "ognl";
70     }
71     
72 }
View Code

要跳转到的jsp页面:

 1 <%@ page language="java" pageEncoding="utf-8"%>
 2 <%@ taglib uri="/struts-tags"   prefix="s"%>
 3 <html>
 4   <head>
 5     <title>My JSP 'index.jsp' starting page</title>
 6     <meta http-equiv="description" content="This is my page">
 7   </head>
 8   <body> 
 9     使用EL表达式取值-----------------------------------------<br>
10     ${requestScope.username}<br>
11     ${sessionScope.username}<br>
12     ${applicationScope.username}<br><br><br><br>
13     使用Ognl表达式取值-----------------------------------------<br>
14     1 # 如果访问其他Context中的对象,由于他们不是根对象,所以在访问时,需要添加#前缀。<br>
15     <s:property value="#request.username"/><br>
16     <s:property value="#session.username"/><br>
17     <s:property value="#application.username"/><br><br>
18     <s:property value="#request['username']"/><br>
19     <s:property value="#parameters.cid[0]"/><br>
20     <s:property value="#attr.username"/><br><br>
21     2 # 如果要访问根对象(即ValueStack)中对象的属性,则可以省略#命名对象,直接访问该对象的属性即可。<br>
22     <s:property value="msg"/><br><br>
23     深入理解值栈中的 ObjectStack<br>
24     <s:property value="name"/><br>
25     <s:property value="sex"/><br>
26     <s:property value="age"/><br>
27     <s:property value="salary"/><br><br>
28     
29     
30     用法3:构造Map<br>
31     <s:radio list="#{'01':'男','02':'女'}"></s:radio><br><br><br><br>
32     %的用法:“%”符号的用途是在标签的属性值被理解为字符串类型时,告诉执行环境%{}里的是OGNL表达式。 <br>
33     <s:property value="#request.username"/><br>
34     <s:property value="%{#request.username}"/>%{}是万能用法,无论里面的表达式是不是ognl表达式,都会强制理解为ognl表达式<br><br>
35     
36     “$”有两个主要的用途<br>
37     *  用于在国际化资源文件中,引用OGNL表达式<br>
38     <s:text name="ognl" /><br><br>
39     
40     *  在Struts 2配置文件中,引用OGNL表达式<br>
41     <s:property value="#parameters.msgxx[0]"/><br><br>
42 
43     <s:debug></s:debug>
44   </body>
45 </html>
View Code

起始页test.jsp:

<%@ page language="java" pageEncoding="utf-8" contentType="text/html; charset=utf-8"%>
<%@ taglib uri="/struts-tags"   prefix="s"%>
<html>
  <head>
    <title>My JSP 'index.jsp' starting page</title>
    </head>
  <body>
      测试值栈:<br>
        <a href="${pageContext.request.contextPath}/ognl/ValueStackAction_test.action">test</a><br>
        <br>
        <br>
        <br>
      测试ognl表达式的用法<br> 
        <a href="${pageContext.request.contextPath}/ognl/OgnlAction_test.action?cid=9">test</a><br>
      
      测试标签<br>
        <a href="${pageContext.request.contextPath}/ognl/OgnlTagAction_test.action?cid=9">test</a><br>
  </body>
</html>
View Code
萧萧弈寒的主页 萧萧弈寒 | 初学一级 | 园豆:170
提问于:2015-04-26 01:32
< >
分享
最佳答案
0

要跳转的jsp页面31行改为:

<s:radio list="#{'01':'男','02':'女'}" name="sex" label="性别"/><br><br>

萧萧弈寒 | 初学一级 |园豆:170 | 2015-04-26 12:06
清除回答草稿
   您需要登录以后才能回答,未注册用户请先注册