Introduction to Struts2 framework and usage introduction

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1 What is ValueStack

It is called the value stack, the data structure of shared data provided by Struts

2 Why use ValueStack

Pass data from the controller to the browser
Store object information related to the request (session/application)

3 Life cycle of the ValueStack object

Request entry After reaching the server, a ValueStack object will be created in the memory; when the request processing is completed, the ValueStack object will be cleared

4 How to access the data in ValueStack

Using OGNL expression Expression acquisition
Use EL expression to obtain

5 Area division of data stored in ValueStack

Contents (stack structure) Use OGNL or EL to obtain data
Context (Map structure ) Use #key to obtain data

7 Case: Pass values ​​from the controller to the browser and display the valueStack area

　7.1 Guide package

　　

 1 <project> 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>

pom.xml

7.2 Configuration file

7.2.1 spring_context.xml

Configuring annotation scanning

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 1 <?xml  version="1.0" encoding="UTF-8"?> 2 <beans>18 19     <!-- 配置组件扫描 -->20     <component-scan></component-scan>21     22 </beans>

spring_context.xml

7.2.2 struts.xml

Configure access path, access network name, action processing class

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 1 <?xml  version="1.0" encoding="UTF-8"?> 2  3 nbsp;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>11         <action>12             <result>13                 /WEB-INF/jsp/msg.jsp14             </result>15         </action>16     </package>17     18     <package>19         <action>20             <result>21                 /WEB-INF/jsp/valueStack.jsp22             </result>23         </action>24     </package>25     26 </struts>27     28

struts.xml

7.2.3 web.xml

Configure the spring listener

Configure the spring configuration file location

Configure the main controller

 1 <?xml  version="1.0" encoding="UTF-8"?> 2 <web-app> 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>

web.xml

7.3 Writing action processing class

 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 @Controller12 @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 }

ValueStackAction.java

Entity classes that need to be used in the control class

 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 stub14     }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     @Override22     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     @Override29     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     @Override63     public String toString() {64         return "Person [id=" + id + ", name=" + name + ", message=" + message + "]";65     }66     67     68 }

Person.java

 

　　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

　　　　　　

　　　　　　

　　　　　　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  3      4 <!-- 引入struts2标签库 -->     5  6      7 nbsp;html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 8  9 10 <meta>11 <title>Insert title here</title>12 13 14     <h2 id="跟valueStack有关的页面">跟valueStack有关的页面</h2>15     <hr><hr>16     17     <h2 id="利用EL表达式从valuesStack中获取数据">利用EL表达式从valuesStack中获取数据</h2>18     <h3 id="message">${message }</h3>19     <hr>20     <h3 id="loginName">${loginName }</h3>21     <hr>22     <h3 id="password">${password }</h3>23     <hr><hr>24     25     <h2 id="利用OGNL表达式获取valueStack中的数据">利用OGNL表达式获取valueStack中的数据</h2>26     <h3><property></property></h3>27     <hr>28     <h3><property></property></h3>29     <hr>30     <h3><property></property></h3>31 32     <hr><hr>33     34     <debug></debug>35 36 

valueStack.jsp

 　　7.5 项目结构图　　

　　　　

 

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