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服务器之家 - 编程语言 - Java教程 - Struts2学习笔记(7)-访问Web元素

Struts2学习笔记(7)-访问Web元素

2020-05-15 10:32meaijojo Java教程

这篇文章主要介绍Struts2中访问Web元素的方法,希望能给大家做一个参考。

常用的Web元素有:request、session、application等,而我们一般使用session较多,Struts2如何访问web元素呢?这个是非常重要的内容,因为它能完成程序后台和用户的数据交互,下面以注册为例演示其过程:

1、index.jsp文件

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<%@ page language="java" contentType="text/html; charset=UTF-8"
  pageEncoding="UTF-8"%>
<% 
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!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">
<base href="<%=basePath %>"/>
<title>Insert title here</title>
</head>
<body>
<h1>演示</h1>
<form action="user/user02!register" method="post">
姓名:<input type="text" name="user.name"></input>
<br/>
密码:<input type="text" name="user.password"></input>
<br/>
<input type="submit" value="注册"/>
</form>
</body>
</html>

功能很简单--即用户输入用户名和密码,然后后台可以获得,然后注册成功后显示给用户

2、struts.xml 配置

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<?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>
  <constant name="struts.devMode" value="true" />
  <package name="front" namespace="/user" extends="struts-default">
 
    <action name="user*" class="com.myservice.web.UserAction{1}">
      <result>/success.jsp</result>
      <result name="error">/error.jsp</result>
    </action>
  </package>
</struts>

可以有两种方式完成这个功能

3、第一种(UserAction01)

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package com.myservice.web;
 
import java.util.Map;
 
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
 
public class UserAction01 extends ActionSupport {
  /**
   *
   */
  private static final long serialVersionUID = 1L;
  private User user;
  private Map request;
  private Map session;
  private Map application;
  public UserAction01(){
    request = (Map)ActionContext.getContext().get("request");
    session = ActionContext.getContext().getSession();
    application = ActionContext.getContext().getApplication();
  }
    public String register(){
    request.put("name", user.getName());
    request.put("password", user.getPassword());
    return SUCCESS;
  }
  public User getUser() {
    return user;
  }
  public void setUser(User user) {
    this.user = user;
  }
   
}

这个方式是用ActionContext.getContext()方法获得context,然后得到request和session以及application

4、另外一种方式(UserAction02)非常常见,也是非常著名的方式-----Ioc(控制反转)和DI(依赖注入),它需要实现3个接口如下:

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package com.myservice.web;
 
import java.util.Map;
 
import org.apache.struts2.interceptor.ApplicationAware;
import org.apache.struts2.interceptor.RequestAware;
import org.apache.struts2.interceptor.SessionAware;
 
import com.opensymphony.xwork2.ActionSupport;
 
public class UserAction02 extends ActionSupport implements RequestAware, SessionAware,ApplicationAware{
  private Map<String, Object> request;
  private Map<String, Object> session;
  private Map<String, Object> application;
  private User user;
   
   
  public User getUser() {
    return user;
  }
 
  public void setUser(User user) {
    this.user = user;
  }
 
  public String register(){
    request.put("name", user.getName());
    request.put("password", user.getPassword());
    return SUCCESS;
  }
   
  @Override
  public void setApplication(Map<String, Object> application) {
    // TODO Auto-generated method stub
    this.application = application;
  }
 
  @Override
  public void setSession(Map<String, Object> session) {
    // TODO Auto-generated method stub
    this.session = session;
  }
 
  @Override
  public void setRequest(Map<String, Object> request) {
    // TODO Auto-generated method stub
    this.request = request;
  }
 
}

这样就实现了一个功能--将user的名称和密码都放入request中,在使用时我们只需取出即可

5、success.jsp将request中内容取出并显示

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<%@ page language="java" contentType="text/html; charset=UTF-8"
  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>
<h3>成功注册</h3>
<s:property value="#request.name"/>注册成功,密码为:<s:property value="#request.password"/>
</body>
</html>

其结果显示为:

Struts2学习笔记(7)-访问Web元素

Struts2学习笔记(7)-访问Web元素

以上就是Struts2中访问Web元素的全部内容,希望能给大家一个参考,也希望大家多多支持服务器之家。

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