Struts2 result中的type常用的四种类型

骑猪看日落 2022-05-17 03:19 156阅读 0赞

**dispatcher**:result type默认的类型，相当于servlet的foward方式跳转页面。客户端看到的是struts2中配置的地址，而不是真正页面的地址，一般用于跳转到jsp页面,页面能拿到值  
**redirect**:页面重定向，客户端跳转，数据全部丢失，地址栏发生变化，页面不能拿到值  
**chain**:将请求转发给一个Action，Action能通过getAttribute(“uname”)拿到值  
**redirect-action**:一般用于跳转到Action，Action不能通过getAttribute(“uname”)拿到值

**前两种的xml action的配置如下(传值给jsp)**：

<result type="redirect-action">/success.jsp</result>

**后两种的xml action的配置如下(传值给Action)**：

<result type="redirect-action">/TestAction</result>

**success.jsp**代码如下

<%@ page language="java" contentType="text/html; charset=UTF-8" isELIgnored="false" pageEncoding="UTF-8"%>
    <%@ taglib uri="/struts-tags" prefix="s"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Insert title here</title>
    </head>
    <body>
    <s:debug></s:debug>
    
    <h3>从debug的值栈中拿值:</h3><br>
    用户名：<s:property value="uname"/>=======密码：<s:property value="upwd"/>
    
    <h3>通过四种跳转方式拿值:</h3><br>
    
    用户名：${request.uname}=======密码：${request.upwd}
    </body>
    </html>

**客户端login.jsp代码如下：**

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Insert title here</title>
    </head>
    <body>
    <form action="LoginAction" method="post">
      用户名：<input type="text" name="uname"><br>
        密码：<input type="password" name="upwd"><br>
        <input type="submit" value="登录">
    </form>
    </body>
    </html>

**LoginAction:接受客户端（login.jsp）的数据代码如下：**

package com.zs.action;
    
    import javax.servlet.http.HttpServletRequest;
    
    import org.apache.struts2.ServletActionContext;
    
    import com.opensymphony.xwork2.ActionSupport;
    
    public class LoginAction extends ActionSupport{ 
    
        private String uname;
        private String upwd;
        private HttpServletRequest request;
        public String getUname() {
            return uname;
        }
    
        public void setUname(String uname) {
            this.uname = uname;
        }
    
        public String getUpwd() {
            return upwd;
        }
    
        public void setUpwd(String upwd) {
            this.upwd = upwd;
        }
    
        public String test() {
            //测试响应到页面的几种请求方式
            request=ServletActionContext.getRequest();
            request.setAttribute("uname", uname);
            request.setAttribute("upwd", upwd);
            System.out.println("uname:"+uname+"upwd:"+upwd);
            return SUCCESS;
        }
    }

**TestAction测试后两种方式的Action代码如下：**

package com.zs.action;
    
    import javax.servlet.http.HttpServletRequest;
    
    import org.apache.struts2.ServletActionContext;
    
    import com.opensymphony.xwork2.ActionSupport;
    
    public class TestAction extends ActionSupport{ 
        private HttpServletRequest request;
        public String test() {
            request=ServletActionContext.getRequest();
            //测试redirect-action这种方式是否拿到数据
            System.out.println("uname:"+request.getAttribute("uname")+"=====upwd:"+request.getAttribute("upwd"));
            return NONE;
        }
    
    }

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