Struts 2常用的Ajax标签

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Struts 2对Ajax的支持
•Struts 2对Ajax提供了很好的支持
–Struts 2.1提供了基于Dojo的Ajax标签,对Ajax操作进行了进步封装,可以更快捷容易的使用Ajax
 
•使用Struts 2.1的Ajax标签前必须进行如下操作
1)将struts2-dojo-plugin-2.1.x.x.jar复制到WEB-INF\lib目录
 
2)在JSP页面中导入Ajax标签
<!-- 引入Ajax标签 -->
<%@ taglib uri="/struts-dojo-tags" prefix="sx"%>
 
3)在JSP页面中加入head标签,负责在页面上导入Dojo所需要的CSS库和javascript
    <head>
        <!-- 在JSP页面中加入head标签
            负责在页面上导入Dojo所需要的CSS库和JavaScript库 -->
        <sx:head />
    </head>

Struts 2.1Ajax标签
方法名
说    明
<sx:div>
创建一个div区域,可以通过Ajax向其中加载内容,以实现局部刷新 ?
<sx:submit>
通过Ajax来更新某个元素的内容或提交表单
<sx:a>
通过Ajax来更新某个元素的内容或提交表单
<sx:tabbedPanel>
创建一个标签面板,由<s:div>来提供内容。
<sx:autocompleter>
根据用户输入提供输入建议,或者帮助用户自动完成输入
<sx:tree>
创建一个支持Ajax的树形组件(Widget)
 

div标签例子
•使用Ajax技术实现如下需求:
 
  –页面有三个div:div1、div2、div3
  –div1的内容每隔5秒时间自动更新一次,每隔30分钟提示用户休息一下(刷新多次)
  –开始访问时,在div2中显示欢迎信息(刷新一次)
  –整个访问过程中div3中内容保持不变(无刷新)
 
使用<sx:div>标签来实现

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实现代码:

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<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!-- 引入struts2的标签库 -->
<%@ taglib uri="/struts-tags" prefix="s"%>
<!-- 引入Ajax标签 -->
<%@ taglib uri="/struts-dojo-tags" prefix="sx"%>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://"
            + request.getServerName() + ":" + request.getServerPort()
            + path + "/";
%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
    <head>
        <base href="<%=basePath%>">

        <title>My JSP ‘ajaxTime.jsp‘ starting page</title>

        <meta http-equiv="pragma" content="no-cache">
        <meta http-equiv="cache-control" content="no-cache">
        <meta http-equiv="expires" content="0">
        <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
        <meta http-equiv="description" content="This is my page">
        <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->
        <!-- 在JSP页面中加入head标签
            负责在页面上导入Dojo所需要的CSS库和JavaScript库 -->
        <sx:head />
    </head>

    <body>
        <s:url id="time" value="time.action" />
        <s:url id="welcome" value="welcome.action" />

        <!-- 每隔1秒异步访问一次 -->
        <sx:div href="%{time}" updateFreq="1000" />
        <!-- 只异步访问一次 -->
        <sx:div href="%{welcome}" />
        <!-- 无异步访问-->
        <sx:div>
            初始化的内容!
        </sx:div>
    </body>
</html>
ajaxTime.jsp
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<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="/struts-tags" prefix="s"%>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://"
            + request.getServerName() + ":" + request.getServerPort()
            + path + "/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
    <head>
        <base href="<%=basePath%>">

        <title>My JSP ‘time.jsp‘ starting page</title>

        <meta http-equiv="pragma" content="no-cache">
        <meta http-equiv="cache-control" content="no-cache">
        <meta http-equiv="expires" content="0">
        <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
        <meta http-equiv="description" content="This is my page">
        <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->

    </head>

    <body>
        <%
            //获得当前时间
            long currentTime = System.currentTimeMillis();
            
            //取出session中存入的现在时间
            Long stratTime = (Long) session.getAttribute("currentTime");
            if (stratTime == null) {
                //第一次访问
                session.setAttribute("currentTime", currentTime);
            } else {
                //以秒计算计算已用时间
                long used = (currentTime - stratTime) / 1000;
                session.setAttribute("used", used);
                //当用户浏览网页时间超过60秒则提示用户休息一下。
                boolean flag = false;
                if (used > 60) {
                    flag = true;
                }
                session.setAttribute("flag", flag);
            }
        %>
        <s:if test="#session.flag==true">
         你该稍微休息一下了。
         </s:if>
        <s:else>
         你已经访问的时间:<s:property value="#session.used" default="0" /></s:else>
    </body>
</html>
time.jsp
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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" "struts-2.1.dtd" >
<struts>
    <package name="struts2" extends="struts-default" namespace="/" >
        <action name="time">
            <!-- name属性不写默认success -->
            <result>/time.jsp</result>            
        </action>
        <action name="welcome">
            <result>/welcome.jsp</result>            
        </action>
    </package>
</struts>
struts.xml
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<%@ page language="java" import="java.util.*" 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">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP ‘welcome.jsp‘ starting page</title>
    
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->

  </head>
  
  <body>
        欢迎你登录本系统!
  </body>
</html>
welcome.jsp
 
submit和a标签例子
•使用Ajax技术实现如下需求:
 
  –页面有两个div,还有一个超链接
  –单击超链接后在div1中出现登录表单
  –如果登录成功,在div2中显示登录成功;登录失败在div2中显示登录失败
 
使用<sx:div>标签来定义div,使用<sx:a>和<sx:submit>定义超链接和提交按钮实现

 技术分享技术分享

实现代码:

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package com.entity;
/**
 * 用户类
 * @author asus
 *
 */
public class Users {

    /** 属性 */
    private String name;
    private String password;
    
    /** 构造方法 */
    public Users() {
        super();
    }
    public Users(String name, String password) {
        super();
        this.name = name;
        this.password = password;
    }
    
    /** javaBean */
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    
}
Users实体类
技术分享
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!-- 引入Struts2标签库 -->
<%@ taglib uri="/struts-tags" prefix="s" %>
<!-- 引入Ajax标签库 -->
<%@ taglib uri="/struts-dojo-tags" prefix="sx" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP ‘home.jsp‘ starting page</title>
    
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->
<!-- 在JSP页面中加入head标签
            负责在页面上导入Dojo所需要的CSS库和JavaScript库 -->
        <sx:head/>
  </head>
  
  <body>
          <!-- url标签 用于生成一个URL地址 -->
          <s:url id="login" value="tologin.action" />
          <!-- 单击超链接异步访问指定Action -->
        <sx:a href="%{login}" targets="div1" >登录</sx:a>
        
        
        <sx:div id="div1" cssStyle="border:1px solid red;" >
            第一个sx:div显示登录
        </sx:div><br>
        <sx:div id="div2" cssStyle="border:1px solid green" >
            第二个DIV,显示登录结果。
        </sx:div>
  </body>
</html>
home.jsp 主页面
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<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!-- 引入struts2的标签库 -->
<%@ taglib uri="/struts-tags" prefix="s"%>
<!-- 引入Ajax标签 -->
<%@ taglib uri="/struts-dojo-tags" prefix="sx"%>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://"
            + request.getServerName() + ":" + request.getServerPort()
            + path + "/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
    <head>
        <base href="<%=basePath%>">

        <title>My JSP ‘ajaxTime.jsp‘ starting page</title>

        <meta http-equiv="pragma" content="no-cache">
        <meta http-equiv="cache-control" content="no-cache">
        <meta http-equiv="expires" content="0">
        <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
        <meta http-equiv="description" content="This is my page">
        <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->
        <!-- 在JSP页面中加入head标签
            负责在页面上导入Dojo所需要的CSS库和JavaScript库 -->
        <sx:head />
    </head>
    <body>
        <h2>用户登录</h2>
        <!-- Struts2 表单标签 -->
        <s:form id="s_form" action="login.action" method="post" theme="simple">
            <br>
                   用户名: <s:textfield label="用户名" name="user.name" />
            <br>
                   密码:     <s:textfield label="密码" name="user.password" />
            <br>
                <!-- 表单内异步提交表单  -->
                <sx:submit type="button" value="表单内异步提交按钮" targets="div2" />
        </s:form>
            <!-- 表单外异步提交 -->
            <sx:submit type="button" value="表单外异步提交按钮" formId="s_form" targets="div2"/>
            <sx:a formId="s_form" targets="div2" >我也可以提交表单</sx:a>
    </body>
</html>
login.jsp 嵌入登陆页面
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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" "struts-2.1.dtd" >
<struts>
    <package name="struts2" extends="struts-default" namespace="/" >
        
        <!-- 单击“用户登录”超链接显示登录菜单 -->
        <action name="tologin" >
            <result >/login.jsp</result>
        </action>
        
        <!-- 单击表单提交按钮显示登录结果 -->
        <action name="login" class="com.struts.LoginAction" method="login" >
            <result>/success.jsp</result>    
            <result name="error">/error.jsp</result>
        </action>
    </package>
</struts>
struts.xml 配置
技术分享
package com.struts;

import com.entity.Users;
import com.opensymphony.xwork2.ActionSupport;
/**
 * 控制器类
 * 作用:处理登录的请求
 * @author asus
 *
 */
public class LoginAction extends ActionSupport {

    /** 属性 */
    private Users user;
    
    /** 重写execute方法 :此方法作用,为指定处理请求的方法时,默认走此方法*/
    public String execute(){
        
        return "";
    }
    
    /** 登录验证的方法 */
    public String login(){
        
        if(user!=null){
            if(user.getName().equals("admin") && user.getPassword().equals("admin")){
                return SUCCESS;
            }
        }
        
        return ERROR;
    }

    /** JavaBean */
    public Users getUser() {
        return user;
    }

    public void setUser(Users user) {
        this.user = user;
    }
    
}
LoginAction 控制器
技术分享
<%@ page language="java" import="java.util.*" 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">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP ‘success.jsp‘ starting page</title>
    
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->

  </head>
  
  <body>
        登录成功!
  </body>
</html>
success.jsp 登录成功页面
技术分享
<%@ page language="java" import="java.util.*" 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">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP ‘file.jsp‘ starting page</title>
    
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->

  </head>
  
  <body>
        登陆失败!
  </body>
</html>
error.jsp 登录失败页面

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