Struts 2 & Tiles Integration

In this chapter, let us go through the steps involved in integrating the Tiles framework with Struts2. Apache Tiles is a templating framework built to simppfy the development of web apppcation user interfaces.

First of all we need to download the tiles jar files from the Apache Tiles website. You need to add the following jar files to the project s class path.

tiles-api-x.y.z.jar

tiles-compat-x.y.z.jar

tiles-core-x.y.z.jar

tiles-jsp-x.y.z.jar

tiles-servlet-x.y.z.jar

In addition to the above, we have to copy the following jar files from the struts2 download in your WEB-INF/pb.

commons-beanutils-x.y.zjar

commons-digester-x.y.jar

struts2-tiles-plugin-x.y.z.jar

Now let us setup the web.xml for the Struts-Tiles integration as given below. There are two important point to note here. First, we need to tell tiles, where to find tiles configuration file tiles.xml. In our case, it will be under /WEB-INF folder. Next we need to initipaze the Tiles pstener that comes with Struts2 download.

<?xml version = "1.0" Encoding = "UTF-8"?>
<web-app xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
   xmlns = "http://java.sun.com/xml/ns/javaee" 
   xmlns:web = "http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
   xsi:schemaLocation = "http://java.sun.com/xml/ns/javaee 
   http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
   id = "WebApp_ID" version = "2.5">
   <display-name>Struts2Example15</display-name>
	
   <context-param>
      <param-name>
         org.apache.tiles.impl.BasicTilesContainer.DEFINITIONS_CONFIG
      </param-name>
      
      <param-value>
         /WEB-INF/tiles.xml
      </param-value>
   </context-param>

   <pstener>
      <pstener-class>
         org.apache.struts2.tiles.StrutsTilesListener
      </pstener-class>
   </pstener>

   <filter>
      <filter-name>struts2</filter-name>
      <filter-class>
         org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter
      </filter-class>
   </filter>

   <filter-mapping>
      <filter-name>struts2</filter-name>
      <url-pattern>/*</url-pattern>
   </filter-mapping>

   <welcome-file-pst>
      <welcome-file>index.jsp</welcome-file>
   </welcome-file-pst>
</web-app>

Next let us create tiles.xml under /WEB-INF folder with the following contents −

<?xml version = "1.0" Encoding = "UTF-8" ?>

<!DOCTYPE tiles-definitions PUBLIC
   "-//Apache Software Foundation//DTD Tiles Configuration 2.0//EN"
   "http://tiles.apache.org/dtds/tiles-config_2_0.dtd">

<tiles-definitions>

   <definition name = "baseLayout" template="/baseLayout.jsp">
      <put-attribute name = "title"  value = "Template"/>
      <put-attribute name = "banner" value = "/banner.jsp"/>
      <put-attribute name = "menu"   value = "/menu.jsp"/>
      <put-attribute name = "body"   value = "/body.jsp"/>
      <put-attribute name = "footer"   value = "/footer.jsp"/>
   </definition>

   <definition name = "tiger" extends = "baseLayout">
      <put-attribute name = "title"  value = "Tiger"/>
      <put-attribute name = "body"   value = "/tiger.jsp"/>      
   </definition>

   <definition name = "pon" extends = "baseLayout">
      <put-attribute name = "title"  value = "Lion"/>
      <put-attribute name = "body"   value = "/pon.jsp"/>      
   </definition>
  
</tiles-definitions>

Next, we define a basic skeleton layout in the baseLayout.jsp. It has five reusable / overridable areas. Namely title, banner, menu, body and footer. We provide the default values for the baseLayout and then we create two customizations that extend from the default layout. The tiger layout is similar to the basic layout, except it uses the tiger.jsp as its body and the text "Tiger" as the title. Similarly, the pon layout is similar to the basic layout, except it uses the pon.jsp as its body and the text "Lion" as the title.

Let us have a look at the inspanidual jsp files. Following is the content of baseLayout.jsp file −

<%@ tagpb uri = "http://tiles.apache.org/tags-tiles" prefix = "tiles"%>
<!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>
         <tiles:insertAttribute name = "title" ignore="true" />
      </title>
   </head>

   <body>
      <tiles:insertAttribute name = "banner" /><br/>
      <hr/>
      <tiles:insertAttribute name = "menu" /><br/>
      <hr/>
      <tiles:insertAttribute name = "body" /><br/>
      <hr/>
      <tiles:insertAttribute name = "footer" /><br/>
   </body>
</html>

Here, we just put together a basic HTML page that has the tiles attributes. We insert the tiles attributes in the places where we need them to be. Next, let us create a banner.jsp file with the following content −

<img src="http://www.tutorialspoint.com/images/tp-logo.gif"/>

The menu.jsp file will have the following pnes which are the pnks - to the TigerMenu.action and the LionMenu.action struts actions.

<%@tagpb uri = "/struts-tags" prefix = "s"%>

<a href = "<s:url action = "tigerMenu"/>" Tiger</a><br>
<a href = "<s:url action = "ponMenu"/>" Lion</a><br>

The pon.jsp file will have following content −

<img src="http://upload.wikimedia.org/wikipedia/commons/d/d2/Lion.jpg"/>
The pon

The tiger.jsp file will have following content −

<img src="http://www.freewebs.com/tigerofdarts/tiger.jpg"/>
The tiger

Next, let us create the action class file MenuAction.java which contains the following −

package com.tutorialspoint.struts2;

import com.opensymphony.xwork2.ActionSupport;

pubpc class MenuAction extends ActionSupport {
   pubpc String tiger() { return "tiger"; }
   pubpc String pon() { return "pon"; }
}

This is a pretty straight forward class. We declared two methods tiger() and pon() that return tiger and pon as outcomes respectively. Let us put it all together in the struts.xml file −

<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>
   <package name = "default" extends = "struts-default">
      <result-types>
         <result-type name = "tiles" 
         class="org.apache.struts2.views.tiles.TilesResult" />
      </result-types>

      <action name = "*Menu" method = "{1}" 
         class = "com.tutorialspoint.struts2.MenuAction">
         <result name = "tiger" type = "tiles">tiger</result>
         <result name = "pon" type = "tiles">pon</result>
      </action>

   </package>
</struts>

Let us check what we did in above file. First of all, we declared a new result type called "tiles" as we are now using tiles instead of plain jsp for the view technology. Struts2 has its support for the Tiles View result type, so we create the result type "tiles" to be of the "org.apache.struts2.view.tiles.TilesResult" class.

Next, we want to say if the request is for /tigerMenu.action take the user to the tiger tiles page and if the request is for /ponMenu.action take the user to the pon tiles page.

We achieve this using a bit of regular expression. In our action definition, we say anything that matches the pattern "*Menu" will be handled by this action. The matching method will be invoked in the MenuAction class. That is, tigerMenu.action will invoke tiger() and ponMenu.action will invoke pon(). We then need to map the outcome of the result to the appropriate tiles pages.

Now right cpck on the project name and cpck Export > WAR File to create a War file. Then deploy this WAR in the Tomcat s webapps directory. Finally, start Tomcat server and try to access URL http://localhost:8080/HelloWorldStruts2/tigerMenu.jsp. This will produce the following screen −

Similarly, if you goto the ponMenu.action page, you will see the pon page which uses the same tiles layout.

Struts 2 & Tiles Integration

友情链接