BAEL-1273: RSS improvements with a custom model (#3665)

* BAEL-1216: improve tests

* BAEL-1448: Update Spring 5 articles to use the release version

* Setting up the Maven Wrapper on a maven project

* Add Maven Wrapper on spring-boot module

* simple add

* BAEL-976: Update spring version

* BAEL-1273: Display RSS feed with spring mvc (AbstractRssFeedView)

* Move RSS feed with Spring MVC from spring-boot to spring-mvc-simple

* BAEL-1285: Update Jackson articles

* BAEL-1273: implement both MVC and Rest approach to serve RSS content

* RSS(XML & Json) with a custom model

* BAEL-1273: remove a resource

spring-mvc-simple/pom.xml

@@ -31,9 +31,16 @@
         <junit.jupiter.version>5.0.2</junit.jupiter.version>
         <junit.platform.version>1.0.2</junit.platform.version>
         <rome.version>1.9.0</rome.version>
+        <jackson.version>2.9.4</jackson.version>
+        <xstream.version>1.4.9</xstream.version>
     </properties>
 
     <dependencies>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-oxm</artifactId>
+            <version>5.0.2.RELEASE</version>
+        </dependency>
         <dependency>
             <groupId>javax.servlet</groupId>
             <artifactId>javax.servlet-api</artifactId>
@@ -121,6 +128,23 @@
             <artifactId>rome</artifactId>
             <version>${rome.version}</version>
         </dependency>
+
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-xml</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.thoughtworks.xstream</groupId>
+            <artifactId>xstream</artifactId>
+            <version>${xstream.version}</version>
+        </dependency>
     </dependencies>
     <build>
         <pluginManagement>

spring-mvc-simple/src/main/java/com/baeldung/spring/configuration/ApplicationConfiguration.java

@@ -1,26 +1,33 @@
 package com.baeldung.spring.configuration;
 
 import com.baeldung.spring.controller.rss.ArticleRssFeedViewResolver;
+import com.fasterxml.jackson.dataformat.xml.XmlMapper;
+import com.fasterxml.jackson.dataformat.xml.ser.ToXmlGenerator;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ComponentScan;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.http.converter.HttpMessageConverter;
+import org.springframework.http.converter.feed.RssChannelHttpMessageConverter;
+import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
+import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
+import org.springframework.http.converter.xml.MappingJackson2XmlHttpMessageConverter;
+import org.springframework.web.accept.ContentNegotiationManager;
 import org.springframework.web.multipart.MultipartResolver;
 import org.springframework.web.multipart.commons.CommonsMultipartResolver;
 import org.springframework.web.servlet.ViewResolver;
 import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
 import org.springframework.web.servlet.config.annotation.EnableWebMvc;
-import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
 import org.springframework.web.servlet.view.ContentNegotiatingViewResolver;
 import org.springframework.web.servlet.view.InternalResourceViewResolver;
-import org.springframework.web.accept.ContentNegotiationManager;
 
-import java.util.List;
 import java.util.ArrayList;
+import java.util.List;
 
 @Configuration
 @EnableWebMvc
 @ComponentScan(basePackages = { "com.baeldung.springmvcforms", "com.baeldung.spring.controller", "com.baeldung.spring.validator" })
-class ApplicationConfiguration implements WebMvcConfigurer {
+class ApplicationConfiguration extends WebMvcConfigurerAdapter {
 
     @Override
     public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
@@ -49,4 +56,19 @@ class ApplicationConfiguration implements WebMvcConfigurer {
         multipartResolver.setMaxUploadSize(5242880);
         return multipartResolver;
     }
+
+    @Override
+    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
+        Jackson2ObjectMapperBuilder builder = Jackson2ObjectMapperBuilder.xml();
+        builder.indentOutput(true);
+
+        XmlMapper xmlMapper = builder.createXmlMapper(true).build();
+        xmlMapper.configure(ToXmlGenerator.Feature.WRITE_XML_DECLARATION, true);
+
+        converters.add(new RssChannelHttpMessageConverter());
+        converters.add(new MappingJackson2HttpMessageConverter());
+        converters.add(new MappingJackson2XmlHttpMessageConverter(xmlMapper));
+
+        super.configureMessageConverters(converters);
+    }
 }

spring-mvc-simple/src/main/java/com/baeldung/spring/controller/rss/ArticleFeed.java

@@ -0,0 +1,27 @@
+package com.baeldung.spring.controller.rss;
+
+import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlElementWrapper;
+import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.List;
+
+@JacksonXmlRootElement(localName="articles")
+public class ArticleFeed extends RssData implements Serializable {
+
+    @JacksonXmlElementWrapper(localName = "items", useWrapping = true)
+    private List<ArticleItem> items = new ArrayList<ArticleItem>();
+
+    public void addItem(ArticleItem articleItem) {
+        this.items.add(articleItem);
+    }
+
+    public List<ArticleItem> getItems() {
+        return items;
+    }
+
+    public void setItems(List<ArticleItem> items) {
+        this.items = items;
+    }
+}

spring-mvc-simple/src/main/java/com/baeldung/spring/controller/rss/ArticleItem.java

@@ -0,0 +1,25 @@
+package com.baeldung.spring.controller.rss;
+
+import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;
+
+import java.io.Serializable;
+
+@JacksonXmlRootElement(localName="article")
+public class ArticleItem extends RssData implements Serializable {
+    private String author;
+
+    public String getAuthor() {
+        return author;
+    }
+
+    public void setAuthor(String author) {
+        this.author = author;
+    }
+
+    @Override
+    public String toString() {
+        return "ArticleItem{" +
+                "author='" + author + '\'' +
+                '}';
+    }
+}

spring-mvc-simple/src/main/java/com/baeldung/spring/controller/rss/ArticleRssController.java

@@ -14,46 +14,38 @@ import java.util.List;
 @Controller
 public class ArticleRssController {
 
-    @GetMapping(value = "/rssMvc")
+    @GetMapping(value = "/rss1")
     public String articleMvcFeed() {
         return "articleFeedView";
     }
 
-    @GetMapping(value = "/rssRest", produces = "application/rss+xml")
+    @GetMapping(value = "/rss2")
     @ResponseBody
-    public String articleRestFeed() throws FeedException {
+    public ArticleFeed articleRestFeed2() {
-        SyndFeed feed = new SyndFeedImpl();
+        ArticleFeed feed = new ArticleFeed();
-        feed.setFeedType("rss_2.0");
         feed.setLink("http://localhost:8080/spring-mvc-simple/rss");
         feed.setTitle("Article Feed");
         feed.setDescription("Article Feed Description");
         feed.setPublishedDate(new Date());
 
-        List list = new ArrayList<SyndEntry>();
+        ArticleItem item1 = new ArticleItem();
-
-        SyndEntry item1 = new SyndEntryImpl();
         item1.setLink("http://www.baeldung.com/netty-exception-handling");
         item1.setTitle("Exceptions in Netty");
-        SyndContent description1 = new SyndContentImpl();
+        item1.setDescription("In this quick article, we’ll be looking at exception handling in Netty.");
-        description1.setValue("In this quick article, we’ll be looking at exception handling in Netty.");
-        item1.setDescription(description1);
         item1.setPublishedDate(new Date());
         item1.setAuthor("Carlos");
 
-        SyndEntry item2 = new SyndEntryImpl();
+        ArticleItem item2 = new ArticleItem();
         item2.setLink("http://www.baeldung.com/cockroachdb-java");
         item2.setTitle("Guide to CockroachDB in Java");
-        SyndContent description2 = new SyndContentImpl();
+        item2.setDescription("This tutorial is an introductory guide to using CockroachDB with Java.");
-        description2.setValue("This tutorial is an introductory guide to using CockroachDB with Java.");
-        item2.setDescription(description2);
         item2.setPublishedDate(new Date());
         item2.setAuthor("Baeldung");
 
-        list.add(item1);
+        feed.addItem(item1);
-        list.add(item2);
+        feed.addItem(item2);
-        feed.setEntries(list);
 
-        return new SyndFeedOutput().outputString(feed);
+        return feed;
     }
 
 }

spring-mvc-simple/src/main/java/com/baeldung/spring/controller/rss/RssData.java

@@ -0,0 +1,56 @@
+package com.baeldung.spring.controller.rss;
+
+import java.io.Serializable;
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
+public class RssData implements Serializable {
+    private String link;
+    private String title;
+    private String description;
+    private String publishedDate;
+
+    public String getLink() {
+        return link;
+    }
+
+    public void setLink(String link) {
+        this.link = link;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    public String getPublishedDate() {
+        return publishedDate;
+    }
+
+    public void setPublishedDate(Date publishedDate) {
+        DateFormat df = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
+        this.publishedDate = df.format(publishedDate);
+    }
+
+    @Override
+    public String toString() {
+        return "RssData{" +
+                "link='" + link + '\'' +
+                ", title='" + title + '\'' +
+                ", description='" + description + '\'' +
+                ", publishedDate=" + publishedDate +
+                '}';
+    }
+}