1、struts.xml

<struts>
 <constant name="struts.devmode" value="false"> 
 <constant name="struts.enable.dynamicmethodinvocation" value="true">
 <constant name="struts.i18n.encoding" value="utf-8"></constant>
 <package name="user" extends="struts-default">                 
        <action name="user" class="com.wxh.action.useraction">
            <result>/useraddsuccess.jsp</result>
            <result name="error">/adderror.jsp</result>
        </action>         
  </package>   
</constant></constant></struts>

package com.wxh.action;
 
import com.opensymphony.xwork2.actionsupport;

public  class useraction extends actionsupport{

private static final long serialversionuid = 1l; 
		
	private string name;
	public string add(){

//逻辑判断
		if(name==null || !name.equals("admin")){
			this.addfielderror("name", "name is error");
			this.addfielderror("name", "name is too long");
			return error;//返回到result的name为“error”所指定的jsp页面。
		}
		return success;
	}
	public string getname() {
		return name;
	}
	public void setname(string name) {
		this.name = name;
	}	
}

<%@taglib uri="/struts-tags" prefix="s" %><!--{cke_protected}{c}%3c!%2d%2d%e7%94%a8%e5%88%b0ognl%e8%a1%a8%e8%be%be%e5%bc%8f%e6%97%b6%e9%9c%80%e8%a6%81%e8%bf%99%e5%8f%a5%2d%2d%3e-->