出现这个错误的原因是一个表单的action没有与之对应的mapping相匹配，注意找找jsp和struts-config看每个细节是否写错
给出一个简单的例子
hello.jsp页面
<%@ page language="java" contentType="text/html;"
pageEncoding="UTF-8"%>
<%@ taglib uri="http://struts.apache.org/tags-bean" prefix="bean"%>
<%@ taglib uri="http://struts.apache.org/tags-html" prefix="html"%>
<%@ taglib uri="http://struts.apache.org/tags-logic" prefix="logic"%>
<html:html lang="true">
<head>
<title>struts</title>
</head>
<body>
<html:errors/>
<logic:present name="msg" scope="request">
<h2>${msg}</h2>
</logic:present>
<h2>${msg}</h2>
<html:form action="/struts-demo/hello.do" method="post">
请输入信息：<html:text property="info"></html:text>
<html:submit value="提交"></html:submit>
</html:form>
</body>
</html:html>struts-config配置文件
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts-config PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 1.3//EN"
"http://struts.apache.org/dtds/struts-config_1_3.dtd">
<struts-config>
<form-beans>
<form-bean name="helloForm" type="struts.form.HelloForm"/>
</form-beans>
<global-exceptions/>
<global-forwards/>
<action-mappings>
<action attribute="helloForm" input="/struts-demo/hello.jsp"
name="helloForm" path="/struts-demo/hello" scope="request"
type="struts.action.HelloAction">
<forward name="show" path="/struts-demo/hello.jsp"></forward>
</action>
</action-mappings>
<message-resources parameter="struts.resource.ApplicationResource"/>
</struts-config>