rest endpoint to retrieve a feed or a category as a feed

src/main/java/com/commafeed/frontend/model/Entry.java

@@ -1,6 +1,7 @@
 package com.commafeed.frontend.model;
 
 import java.io.Serializable;
+import java.util.Arrays;
 import java.util.Date;
 
 import javax.xml.bind.annotation.XmlAccessType;
@@ -9,6 +10,9 @@ import javax.xml.bind.annotation.XmlRootElement;
 
 import com.commafeed.backend.model.FeedEntry;
 import com.commafeed.backend.model.FeedEntryStatus;
+import com.sun.syndication.feed.synd.SyndContentImpl;
+import com.sun.syndication.feed.synd.SyndEntry;
+import com.sun.syndication.feed.synd.SyndEntryImpl;
 import com.wordnik.swagger.annotations.ApiClass;
 import com.wordnik.swagger.annotations.ApiProperty;
 
@@ -23,6 +27,7 @@ public class Entry implements Serializable {
 
 		FeedEntry feedEntry = status.getEntry();
 		entry.setId(String.valueOf(status.getId()));
+		entry.setGuid(feedEntry.getGuid());
 		entry.setTitle(feedEntry.getContent().getTitle());
 		entry.setContent(feedEntry.getContent().getContent());
 		entry.setEnclosureUrl(status.getEntry().getContent().getEnclosureUrl());
@@ -40,9 +45,26 @@ public class Entry implements Serializable {
 		return entry;
 	}
 
+	public SyndEntry asRss() {
+		SyndEntry entry = new SyndEntryImpl();
+
+		entry.setUri(getGuid());
+		entry.setTitle(getTitle());
+
+		SyndContentImpl content = new SyndContentImpl();
+		content.setValue(getContent());
+		entry.setContents(Arrays.asList(content));
+		entry.setLink(getUrl());
+		entry.setPublishedDate(getDate());
+		return entry;
+	}
+
 	@ApiProperty("entry id")
 	private String id;
 
+	@ApiProperty("entry guid")
+	private String guid;
+
 	@ApiProperty("entry title")
 	private String title;
 
@@ -172,4 +194,12 @@ public class Entry implements Serializable {
 		this.enclosureType = enclosureType;
 	}
 
+	public String getGuid() {
+		return guid;
+	}
+
+	public void setGuid(String guid) {
+		this.guid = guid;
+	}
+
 }

src/main/java/com/commafeed/frontend/rest/resources/CategoryREST.java

@@ -1,5 +1,6 @@
 package com.commafeed.frontend.rest.resources;
 
+import java.io.StringWriter;
 import java.util.Calendar;
 import java.util.Collections;
 import java.util.Comparator;
@@ -11,12 +12,16 @@ import javax.ws.rs.DefaultValue;
 import javax.ws.rs.GET;
 import javax.ws.rs.POST;
 import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
 import javax.ws.rs.QueryParam;
+import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
 import javax.ws.rs.core.Response.Status;
 
 import org.apache.commons.lang.ObjectUtils;
 import org.apache.commons.lang.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import com.commafeed.backend.model.FeedCategory;
 import com.commafeed.backend.model.FeedEntryStatus;
@@ -33,6 +38,11 @@ import com.commafeed.frontend.model.request.MarkRequest;
 import com.commafeed.frontend.model.request.RenameRequest;
 import com.commafeed.frontend.rest.Enums.ReadType;
 import com.google.common.base.Preconditions;
+import com.google.common.collect.Lists;
+import com.sun.syndication.feed.synd.SyndEntry;
+import com.sun.syndication.feed.synd.SyndFeed;
+import com.sun.syndication.feed.synd.SyndFeedImpl;
+import com.sun.syndication.io.SyndFeedOutput;
 import com.wordnik.swagger.annotations.Api;
 import com.wordnik.swagger.annotations.ApiOperation;
 import com.wordnik.swagger.annotations.ApiParam;
@@ -41,6 +51,8 @@ import com.wordnik.swagger.annotations.ApiParam;
 @Api(value = "/category", description = "Operations about user categories")
 public class CategoryREST extends AbstractResourceREST {
 
+	private static Logger log = LoggerFactory.getLogger(CategoryREST.class);
+
 	public static final String ALL = "all";
 	public static final String STARRED = "starred";
 
@@ -95,6 +107,46 @@ public class CategoryREST extends AbstractResourceREST {
 		return entries;
 	}
 
+	@Path("/entriesAsFeed")
+	@GET
+	@ApiOperation(value = "Get category entries as feed", notes = "Get a feed of category entries")
+	@Produces(MediaType.APPLICATION_XML)
+	public String getCategoryEntriesAsFeed(
+			@ApiParam(value = "id of the category, 'all' or 'starred'", required = true) @QueryParam("id") String id) {
+
+		Preconditions.checkNotNull(id);
+
+		ReadType readType = ReadType.all;
+		ReadingOrder order = ReadingOrder.desc;
+		int offset = 0;
+		int limit = 20;
+
+		Entries entries = getCategoryEntries(id, readType, offset, limit, order);
+
+		SyndFeed feed = new SyndFeedImpl();
+		feed.setFeedType("rss_2.0");
+		feed.setTitle("CommaFeed - " + entries.getName());
+		feed.setDescription("CommaFeed - " + entries.getName());
+		String publicUrl = applicationSettingsService.get().getPublicUrl();
+		feed.setLink(publicUrl);
+
+		List<SyndEntry> children = Lists.newArrayList();
+		for (Entry entry : entries.getEntries()) {
+			children.add(entry.asRss());
+		}
+		feed.setEntries(children);
+
+		SyndFeedOutput output = new SyndFeedOutput();
+		StringWriter writer = new StringWriter();
+		try {
+			output.output(feed, writer);
+		} catch (Exception e) {
+			writer.write("Could not get feed information");
+			log.error(e.getMessage(), e);
+		}
+		return writer.toString();
+	}
+
 	@Path("/mark")
 	@POST
 	@ApiOperation(value = "Mark category entries", notes = "Mark feed entries of this category as read")

src/main/java/com/commafeed/frontend/rest/resources/FeedREST.java

@@ -1,5 +1,6 @@
 package com.commafeed.frontend.rest.resources;
 
+import java.io.StringWriter;
 import java.util.Calendar;
 import java.util.Date;
 import java.util.List;
@@ -22,6 +23,8 @@ import org.apache.commons.fileupload.disk.DiskFileItemFactory;
 import org.apache.commons.fileupload.servlet.ServletFileUpload;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import com.commafeed.backend.feeds.FetchedFeed;
 import com.commafeed.backend.model.FeedCategory;
@@ -37,7 +40,12 @@ import com.commafeed.frontend.model.request.RenameRequest;
 import com.commafeed.frontend.model.request.SubscribeRequest;
 import com.commafeed.frontend.rest.Enums.ReadType;
 import com.google.common.base.Preconditions;
+import com.google.common.collect.Lists;
 import com.sun.syndication.feed.opml.Opml;
+import com.sun.syndication.feed.synd.SyndEntry;
+import com.sun.syndication.feed.synd.SyndFeed;
+import com.sun.syndication.feed.synd.SyndFeedImpl;
+import com.sun.syndication.io.SyndFeedOutput;
 import com.sun.syndication.io.WireFeedOutput;
 import com.wordnik.swagger.annotations.Api;
 import com.wordnik.swagger.annotations.ApiOperation;
@@ -47,6 +55,8 @@ import com.wordnik.swagger.annotations.ApiParam;
 @Api(value = "/feed", description = "Operations about feeds")
 public class FeedREST extends AbstractResourceREST {
 
+	private static Logger log = LoggerFactory.getLogger(FeedREST.class);
+
 	@Path("/entries")
 	@GET
 	@ApiOperation(value = "Get feed entries", notes = "Get a list of feed entries", responseClass = "com.commafeed.frontend.model.Entries")
@@ -82,6 +92,46 @@ public class FeedREST extends AbstractResourceREST {
 		return entries;
 	}
 
+	@Path("/entriesAsFeed")
+	@GET
+	@ApiOperation(value = "Get feed entries as a feed", notes = "Get a feed of feed entries")
+	@Produces(MediaType.APPLICATION_XML)
+	public String getFeedEntriesAsFeed(
+			@ApiParam(value = "id of the feed", required = true) @QueryParam("id") String id) {
+
+		Preconditions.checkNotNull(id);
+
+		ReadType readType = ReadType.all;
+		ReadingOrder order = ReadingOrder.desc;
+		int offset = 0;
+		int limit = 20;
+
+		Entries entries = getFeedEntries(id, readType, offset, limit, order);
+
+		SyndFeed feed = new SyndFeedImpl();
+		feed.setFeedType("rss_2.0");
+		feed.setTitle("CommaFeed - " + entries.getName());
+		feed.setDescription("CommaFeed - " + entries.getName());
+		String publicUrl = applicationSettingsService.get().getPublicUrl();
+		feed.setLink(publicUrl);
+
+		List<SyndEntry> children = Lists.newArrayList();
+		for (Entry entry : entries.getEntries()) {
+			children.add(entry.asRss());
+		}
+		feed.setEntries(children);
+
+		SyndFeedOutput output = new SyndFeedOutput();
+		StringWriter writer = new StringWriter();
+		try {
+			output.output(feed, writer);
+		} catch (Exception e) {
+			writer.write("Could not get feed information");
+			log.error(e.getMessage(), e);
+		}
+		return writer.toString();
+	}
+
 	@GET
 	@Path("/fetch")
 	@ApiOperation(value = "Fetch a feed", notes = "Fetch a feed by its url", responseClass = "com.commafeed.backend.model.Feed")