In Spring 3, comes with a abstract class “AbstractRssFeedView” to generate RSS feed view, using java.net’s ROME package. In this tutorial, we show you how to generate a RSS feed view from Spring MVC framework.
Technologies used :
- Spring 3.0.5.RELEASE
- ROME 1.0.0
- JDK 1.6
- Eclipse 3.6
- Maven 3
At the end of the tutorial, when you visit this URL – http://localhost:8080/SpringMVC/rest/rssfeed, browser will return following RSS feed content :
<?xml version="1.0" encoding="UTF-8"?> <rss xmlns:content="http://purl.org/rss/1.0/modules/content/" version="2.0"> <channel> <title>Mkyong Dot Com</title> <link>http://www.mkyong.com</link> <description>Java Tutorials and Examples</description> <item> <title>Spring MVC Tutorial 1</title> <link>http://www.mkyong.com/spring-mvc/tutorial-1</link> <content:encoded>Tutorial 1 summary ...</content:encoded> <pubDate>Tue, 26 Jul 2011 02:26:08 GMT</pubDate> </item> <item> <title>Spring MVC Tutorial 2</title> <link>http://www.mkyong.com/spring-mvc/tutorial-2</link> <content:encoded>Tutorial 2 summary ...</content:encoded> <pubDate>Tue, 26 Jul 2011 02:26:08 GMT</pubDate> </item> </channel> </rss>
1. Directory Structure
Review the final project structure.
2. Project Dependencies
For Maven, declares following dependencies in your pom.xml
.
<properties> <spring.version>3.0.5.RELEASE</spring.version> </properties> <dependencies> <!-- Spring 3 dependencies --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${spring.version}</version> </dependency> <!-- RSS --> <dependency> <groupId>net.java.dev.rome</groupId> <artifactId>rome</artifactId> <version>1.0.0</version> </dependency> <!-- for compile only, your container should have this --> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>2.5</version> <scope>provided</scope> </dependency> </dependencies>
3. Model
A simple POJO, later use this object to generate the RSS feed content.
package com.mkyong.common.model; import java.util.Date; public class SampleContent { String title; String url; String summary; Date createdDate; //getter and seeter methods }
4. AbstractRssFeedView
Create a class extends AbstractRssFeedView, and override the buildFeedMetadata
and buildFeedItems
methods, below code should be self-explanatory.
package com.mkyong.common.rss; import java.util.ArrayList; import java.util.List; import java.util.Map; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.view.feed.AbstractRssFeedView; import com.mkyong.common.model.SampleContent; import com.sun.syndication.feed.rss.Channel; import com.sun.syndication.feed.rss.Content; import com.sun.syndication.feed.rss.Item; public class CustomRssViewer extends AbstractRssFeedView { @Override protected void buildFeedMetadata(Map<String, Object> model, Channel feed, HttpServletRequest request) { feed.setTitle("Mkyong Dot Com"); feed.setDescription("Java Tutorials and Examples"); feed.setLink("http://www.mkyong.com"); super.buildFeedMetadata(model, feed, request); } @Override protected List<Item> buildFeedItems(Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception { @SuppressWarnings("unchecked") List<SampleContent> listContent = (List<SampleContent>) model.get("feedContent"); List<Item> items = new ArrayList<Item>(listContent.size()); for(SampleContent tempContent : listContent ){ Item item = new Item(); Content content = new Content(); content.setValue(tempContent.getSummary()); item.setContent(content); item.setTitle(tempContent.getTitle()); item.setLink(tempContent.getUrl()); item.setPubDate(tempContent.getCreatedDate()); items.add(item); } return items; } }
5. Controller
Spring MVC controller class, generate the rss feed content, and return a view name “rssViewer” (This view name is belong to above “CustomRssViewer“, will register in step 6 later).
package com.mkyong.common.controller; import java.util.ArrayList; import java.util.Date; import java.util.List; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.servlet.ModelAndView; import com.mkyong.common.model.SampleContent; @Controller public class RssController { @RequestMapping(value="/rssfeed", method = RequestMethod.GET) public ModelAndView getFeedInRss() { List<SampleContent> items = new ArrayList<SampleContent>(); SampleContent content = new SampleContent(); content.setTitle("Spring MVC Tutorial 1"); content.setUrl("http://www.mkyong.com/spring-mvc/tutorial-1"); content.setSummary("Tutorial 1 summary ..."); content.setCreatedDate(new Date()); items.add(content); SampleContent content2 = new SampleContent(); content2.setTitle("Spring MVC Tutorial 2"); content2.setUrl("http://www.mkyong.com/spring-mvc/tutorial-2"); content2.setSummary("Tutorial 2 summary ..."); content2.setCreatedDate(new Date()); items.add(content2); ModelAndView mav = new ModelAndView(); mav.setViewName("rssViewer"); mav.addObject("feedContent", items); return mav; } }
6. Spring Bean Registration
In a Spring bean definition file, enable the auto component scanning, and register your “CustomRssViewer
” class and “BeanNameViewResolver
” view resolver, so that when view name “rssViewer” is returned, Spring know it should map to bean id “rssViewer“.
File : mvc-dispatcher-servlet.xml
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> <context:component-scan base-package="com.mkyong.common.controller" /> <!-- Map returned view name "rssViewer" to bean id "rssViewer" --> <bean class="org.springframework.web.servlet.view.BeanNameViewResolver" /> <bean id="rssViewer" class="com.mkyong.common.rss.CustomRssViewer" /> </beans>
File content of
web.xml
is omitted, just a standard configuration, if you are interest, download this whole project at the end of the article.
7. Demo
URL : http://localhost:8080/SpringMVC/rest/rssfeed
For Atom, you just need to extends
AbstractAtomFeedView
, instead of
AbstractRssFeedView
.