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 simplify the development of web application 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
- commons-beanutils-x.y.zjar
- commons-digester-x.y.jar
- struts2-tiles-plugin-x.y.z.jar
<?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>
<listener>
<listener-class>
org.apache.struts2.tiles.StrutsTilesListener
</listener-class>
</listener>
<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-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</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="lion" extends="baseLayout">
<put-attribute name="title" value="Lion"/>
<put-attribute name="body" value="/lion.jsp"/>
</definition>
</tiles-definitions>
Mext. 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 lion layout is similar to the basic layout, except it uses the lion.jsp as its body and the text "Lion" as the title.Let us have a look at the individual jsp files. Following is the content of baseLayout.jsp file:
<%@ taglib 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 banner.jsp file with the following content:<img src="http://www.tutorialspoint.com/images/tp-logo.gif"/>The menu.jsp file will have following lines which are the links - to the TigerMenu.action and the LionMenu.action struts actions.
<%@taglib uri="/struts-tags" prefix="s"%> <a href="<s:url action="tigerMenu"/>" Tiger</a><br> <a href="<s:url action="lionMenu"/>" Lion</a><br>The lion.jsp file will have following content:
<img src="http://upload.wikimedia.org/wikipedia/commons/d/d2/Lion.jpg"/> The lionThe tiger.jsp file will have following content:
<img src="http://www.freewebs.com/tigerofdarts/tiger.jpg"/> The tigerNext, let us create the action class file MenuAction.java which contains the following:
package com.tecra.struts2;
import com.opensymphony.xwork2.ActionSupport;
public class MenuAction extends ActionSupport {
public String tiger() { return "tiger"; }
public String lion() { return "lion"; }
}
This is a pretty straight forward class. We declared two methods
tiger() and lion() that return tiger and lion 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="lion" type="tiles">lion</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 /lionMenu.action take the user to the lion 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 lionMenu.action will invoke lion(). We then need to map the outcome of the result to the appropriate tiles pages.
Now right click on the project name and click 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 give you following screen:
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