Struts2怎么继承ActionSupport?_maven工程为什么继承不了actionsuppot只有defaultactionsupport-优快云博客

本文详细介绍了如何使用Struts2框架进行Web应用开发，包括配置jar包、创建视图层和控制层，以及设置过滤器的过程。通过示例展示了用户登录功能的实现，包括表单验证和业务逻辑处理。

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Struts2继承ActionSupport首先先准备一下jar包这个官方网站都可以下载，把下载好了jar放到WEB-INF目录下的lib目录里面然后根据内容创建视图层我这里是创建了两个
login.jsp:

<%@ page language="java" contentType="text/html; charset=utf-8"  
    pageEncoding="utf-8"%> 
<%@ taglib prefix="s" uri="/struts-tags"%> 
<html>  
<head>  
<meta http-equiv="Content-Type" content="text/html; utf-8">  
<title>Insert title here</title>  
<style type="text/css">
ul,li {
    list-style-type:none;
    margin:0px;
    float:left;
}
</style>
</head>  
<body>  
   
<form action="helloworldAction" method="post"> 
    <input type="hidden" name="submitFlag" value="login"/>  
    <div> 
        <font color=red><s:fielderror fieldName="account"/></font>
        <br/>
          账号:<input type="text" name="account">
    </div>
    <div>
        <font color=red><s:fielderror fieldName="password"/></font>
        <br/>
            密码:<input type="password" name="password">
    </div>
    <input type="submit" value="提交">  
</form>  
  
</body>  
</html>

welcome.jsp:

<%@ page language="java" contentType="text/html; charset=utf-8"  
    pageEncoding="utf-8"%> 
<%@ taglib prefix="s" uri="/struts-tags"%> 
<html>  
<head>  
<title>welcome</title>  
</head>  
<body>   
	登陆成功!!!	
</body>  
</html>

然后再在src下创建控制层

package cn.javass.hello.struts2impl.action;  

import com.opensymphony.xwork2.ActionSupport;
  
public class HelloWorldAction extends ActionSupport {  
    private String account;  
    private String password;  
    private String submitFlag;  
    public String execute() throws Exception {  
        this.businessExecute();  
        return "toWelcome";  
    }  
    public void validate(){  
        if(account==null || account.trim().length()==0){  
            this.addFieldError("account", "账号不可以为空");  
        }  
        if(password==null || password.trim().length()==0){  
            this.addFieldError("password", "密码不可以为空");  
        }
        if(password!=null && !"".equals(password.trim()) && password.trim().length()<6){  
            this.addFieldError("password", "密码长度至少为6位");  
        }  
    }  
    /** 
     * 示例方法，表示可以执行业务逻辑处理的方法， 
     */  
    public void businessExecute(){  
        System.out.println("用户输入的参数为==="+"account="+account+",password="+password+",submitFlag="+submitFlag);  
    }
    public String getAccount() {
        return account;
    }
    public void setAccount(String account) {
        this.account = account;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getSubmitFlag() {
        return submitFlag;
    }
    public void setSubmitFlag(String submitFlag) {
        this.submitFlag = submitFlag;
    }  
    
}

紧接着在src下建立struts.xml
struts.xml:

<?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="helloworld"  extends="struts-default">  
        <action name="helloworldAction" class="cn.javass.hello.struts2impl.action.HelloWorldAction">  
        <!-- 定义welcome的逻辑视图名，对应welcome.jsp页面 -->
            <result name="toWelcome">/welcome.jsp</result> 
            <!-- 定义input的逻辑视图名，对应login.jsp页面 -->
             <result name="input">/login.jsp</result>   
        </action>  
    </package>    
 </struts>

最后在WEB-INF下的web.xml中设置Struts2的过滤器:

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0"
  xmlns="http://java.sun.com/xml/ns/javaee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
    
 <welcome-file-list>
 <welcome-file>login.jsp</welcome-file>
 </welcome-file-list>
 
 <filter>
 <filter-name>struts2</filter-name>
 <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
 </filter>

 <filter-mapping>
    <filter-name>struts2</filter-name>
    <url-pattern>/*</url-pattern>
 </filter-mapping>

</web-app>

具体内容已实现！
实现后的效果图
在这里插入图片描述