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1 什么是ValueStack
称为值栈，Struts提供的共享数据的数据结构
2 为什么要使用ValueStack
从控制器向浏览器传递数据
存储与请求相关的对象信息（session/application）
3 ValueStack对象的生命周期
请求进入到服务器端后，在内存中就会传创建一个ValueStack对象；当请求处理结束以后，ValueStack对象就会被清除
4 如何访问ValueStack中的数据
利用OGNL表达式获取
利用EL表达式获取
5 在ValueStack中存储数据的区域划分
Contents (栈结构) 利用OGNL或者EL来获取数据
Context （Map结构） 利用 #key 来获取数据
7 案例：从控制器向浏览器传值，展示valueStack区域
7.1 导包
1 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 2 <modelVersion>4.0.0</modelVersion> 3 <groupId>cn.xiangxu</groupId> 4 <artifactId>ssh03</artifactId> 5 <version>0.0.1-SNAPSHOT</version> 6 <packaging>war</packaging> 7 <dependencies> 8 <dependency> 9 <groupId>org.apache.struts</groupId> 10 <artifactId>struts2-core</artifactId> 11 <version>2.3.8</version> 12 </dependency> 13 <dependency> 14 <groupId>org.apache.struts</groupId> 15 <artifactId>struts2-spring-plugin</artifactId> 16 <version>2.3.8</version> 17 </dependency> 18 <dependency> 19 <groupId>org.apache.struts</groupId> 20 <artifactId>struts2-json-plugin</artifactId> 21 <version>2.3.8</version> 22 </dependency> 23 </dependencies> 24 </project>
7.2 配置文件
7.2.1 spring_context.xml
配置注解扫描
1 <?xml version="1.0" encoding="UTF-8"?> 2 <beans xmlns="http://www.springframework.org/schema/beans" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" 4 xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:jee="http://www.springframework.org/schema/jee" 5 xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" 6 xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:util="http://www.springframework.org/schema/util" 7 xmlns:jpa="http://www.springframework.org/schema/data/jpa" 8 xsi:schemaLocation=" 9 http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 10 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd 11 http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd 12 http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.0.xsd 13 http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd 14 http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd 15 http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd 16 http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd 17 http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd"> 18 19 <!-- 配置组件扫描 --> 20 <context:component-scan base-package="cn.xiangxu" /> 21 22 </beans>
7.2.2 struts.xml
配置访问路径、访问网名、action处理类
1 <?xml version="1.0" encoding="UTF-8"?> 2 3 <!DOCTYPE struts PUBLIC 4 "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN" 5 "http://struts.apache.org/dtds/struts-2.3.dtd"> 6 7 <struts> 8 9 <!-- 测试struts整合spring时用 --> 10 <package name="test" namespace="/test" extends="json-default"> 11 <action name="demo"> 12 <result> 13 /WEB-INF/jsp/msg.jsp 14 </result> 15 </action> 16 </package> 17 18 <package name="vs" namespace="/vs" extends="json-default"> 19 <action name="valueStack" class="valueStackAction" method="valueStaceMethod"> 20 <result name="success"> 21 /WEB-INF/jsp/valueStack.jsp 22 </result> 23 </action> 24 </package> 25 26 </struts> 27 28
7.2.3 web.xml
配置spring监听器
配置spring配置文件位置
配置主控制器
1 <?xml version="1.0" encoding="UTF-8"?> 2 <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5"> 3 <display-name>ssh03</display-name> 4 <welcome-file-list> 5 <welcome-file>index.html</welcome-file> 6 <welcome-file>index.htm</welcome-file> 7 <welcome-file>index.jsp</welcome-file> 8 <welcome-file>default.html</welcome-file> 9 <welcome-file>default.htm</welcome-file> 10 <welcome-file>default.jsp</welcome-file> 11 </welcome-file-list> 12 13 <!-- 配置spring监听 14 目的：容器启动时自动加载一些东西到缓存中 --> 15 <listener> 16 <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> 17 </listener> 18 19 <!-- 配置Spring配置文件的位置 --> 20 <context-param> 21 <param-name>contextConfigLocation</param-name> 22 <param-value>classpath:spring_*.xml</param-value> 23 </context-param> 24 25 <!-- 配置主控制器和过滤条件 --> 26 <filter> 27 <filter-name>mvc</filter-name> 28 <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class> 29 </filter> 30 <filter-mapping> 31 <filter-name>mvc</filter-name> 32 <url-pattern>/*</url-pattern> 33 </filter-mapping> 34 35 </web-app>
7.3 编写action处理类
1 package cn.xiangxu.action; 2 3 import org.springframework.context.annotation.Scope; 4 import org.springframework.stereotype.Controller; 5 6 import com.opensymphony.xwork2.ActionContext; 7 import com.opensymphony.xwork2.util.ValueStack; 8 9 import cn.xiangxu.entity.Person; 10 11 @Controller 12 @Scope("prototype") 13 public class ValueStackAction { 14 15 private String message; 16 17 public String valueStaceMethod() { 18 System.out.println("跟valueStack相关的action类"); 19 20 message = "我是控制类中的属性message"; 21 22 // 利用工厂方法来获取session对象时就使用下面两行代码 23 ActionContext context = ActionContext.getContext(); 24 context.getSession().put("loginName", "warrior"); // 向session中插入数据 25 26 context.getSession().put("password", "123456"); // 向session中插入数据 27 28 // 利用上下文对象来获取ValueStack对象 29 ValueStack valueStack = context.getValueStack(); 30 31 Person person = new Person(); 32 person.setId("333"); 33 person.setName("fury"); 34 person.setMessage("hello fury"); 35 valueStack.push(person); // 将数据插入到对象栈中 36 37 return "success"; 38 } 39 40 public String getMessage() { 41 return message; 42 } 43 44 public void setMessage(String message) { 45 this.message = message; 46 } 47 48 }
在控制类中需要用到的实体类
1 package cn.xiangxu.entity; 2 3 import java.io.Serializable; 4 5 public class Person implements Serializable { 6 7 private static final long serialVersionUID = -7221161390673280278L; 8 private String id; 9 private String name; 10 private String message; 11 public Person() { 12 super(); 13 // TODO Auto-generated constructor stub 14 } 15 public Person(String id, String name, String message) { 16 super(); 17 this.id = id; 18 this.name = name; 19 this.message = message; 20 } 21 @Override 22 public int hashCode() { 23 final int prime = 31; 24 int result = 1; 25 result = prime * result + ((id == null) ? 0 : id.hashCode()); 26 return result; 27 } 28 @Override 29 public boolean equals(Object obj) { 30 if (this == obj) 31 return true; 32 if (obj == null) 33 return false; 34 if (getClass() != obj.getClass()) 35 return false; 36 Person other = (Person) obj; 37 if (id == null) { 38 if (other.id != null) 39 return false; 40 } else if (!id.equals(other.id)) 41 return false; 42 return true; 43 } 44 public String getId() { 45 return id; 46 } 47 public void setId(String id) { 48 this.id = id; 49 } 50 public String getName() { 51 return name; 52 } 53 public void setName(String name) { 54 this.name = name; 55 } 56 public String getMessage() { 57 return message; 58 } 59 public void setMessage(String message) { 60 this.message = message; 61 } 62 @Override 63 public String toString() { 64 return "Person [id=" + id + ", name=" + name + ", message=" + message + "]"; 65 } 66 67 68 }
7.4 编写jsp页面
7.4.1 利用EL表达式访问ValueStack中的数据的格式
${变量名}
7.4.2 利用OGNL表达式访问ValueStack中的数据的格式
<s:property value="变量名"/>
<s:property value="#session.变量名"/>
注意：为什么访问sesseion中的数据时需要在前面加 #session. 是因为....【自己百度去，或者参见本博客顶端的连接；三少能力有限，讲不清楚】
注意：在读取栈结构中的数据时是从栈顶开始读的，如果有两个变量的名字相同，那么读取到的只会是相对前面的那个变量的值
1 <%@ page language="java" contentType="text/html; charset=utf-8" 2 pageEncoding="utf-8"%> 3 4 <!-- 引入struts2标签库 --> 5 <%@ taglib prefix="s" uri="/struts-tags" %> 6 7 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 8 <html> 9 <head> 10 <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> 11 <title>Insert title here</title> 12 </head> 13 <body> 14 <h2>跟valueStack有关的页面</h2> 15 <hr /><hr /> 16 17 <h2>利用EL表达式从valuesStack中获取数据</h2> 18 <h3>${message }</h3> 19 <hr /> 20 <h3>${loginName }</h3> 21 <hr /> 22 <h3>${password }</h3> 23 <hr /><hr /> 24 25 <h2>利用OGNL表达式获取valueStack中的数据</h2> 26 <h3><s:property value="message"/></h3> 27 <hr /> 28 <h3><s:property value="#session.loginName"/></h3> 29 <hr /> 30 <h3><s:property value="#session.password"/></h3> 31 32 <hr /><hr /> 33 34 <s:debug></s:debug> 35 </body> 36 </html>
7.5 项目结构图
