ROME 라이브러리를 이용하여 RSS 피드 읽어 오기

1. 필요한 라이브러리

• ROME 1.0
• ROME Subprojects인 ROME Fetcher
• JDOM 1.0

2. 피드 읽기 위한 소스
 - RSSApi.java

package client;


import java.net.URL;

import java.net.URLEncoder;

import java.util.Map;


import org.apache.commons.lang.StringUtils;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;


import com.sun.syndication.feed.synd.SyndFeed;

import com.sun.syndication.fetcher.impl.HashMapFeedInfoCache;

import com.sun.syndication.fetcher.impl.HttpClientFeedFetcher;


public class RSSApi 

{

	private final Log log = LogFactory.getLog(this.getClass());

	private URL serviceUrl = null;

	private HttpClientFeedFetcher fetcher = null;

  

	/**

	 * Constructs a RSSApi instance.

	 * @param serviceUrl RSS호출 URL.

	 * @param useLocalCache 응답을 캐싱할 것인지.

   */

	public RSSApi(URL serviceUrl, boolean useLocalCache)

	{

	    super();

	    this.serviceUrl = serviceUrl;

	    fetcher = new HttpClientFeedFetcher();

	    fetcher.setUserAgent("RssAPIFetcher-1.0");

	    if (useLocalCache)

	      fetcher.setFeedInfoCache(HashMapFeedInfoCache.getInstance());

	}

  

	/**

	 * Feed 호출.

	 * @param methodName 실행 함수 이름.

	 * @param params Map 값.

	 * @return SyndFeed 객체.

	 */

	public SyndFeed execute(String methodName, Map<String, String> params) 

	{

	    URL feedUrl = buildUrl(methodName, params);

	    SyndFeed feed = null;

    

	    try {

	    	feed = fetcher.retrieveFeed(feedUrl);

	    } catch (Exception e) {

	    	log.error(e);

	    }

	    return feed;

	}


	/**

	 * 호출 URL Build

	 * @param methodName 실행 함수 이름.

	 * @param params Map 파라미터.

	 * @return

	 */

	private URL buildUrl(String methodName, Map<String,String> params) 

	{

		StringBuilder urlBuilder = null;

		int numParams = 0;

		URL url = null;

		

		try {

			urlBuilder = new StringBuilder(serviceUrl.toString());

			urlBuilder.append("/").append(methodName);

		  

			for (String paramName : params.keySet()) {

			String paramValue = params.get(paramName);

			if (StringUtils.isBlank(paramValue)) {

				continue;

			}

			paramValue = URLEncoder.encode(paramValue, "UTF-8");

			urlBuilder.append(numParams == 0 ? "?" : "&").

			append(paramName).

				append("=").

				append(paramValue);

				numParams++;

			}

			url = new URL(urlBuilder.toString());

			if (log.isDebugEnabled())

			  log.debug("Requesting:[" + 

                               urlBuilder.toString() + "]");

		} catch (Exception e) {

			log.error(e);

		}

		return url;

	}

}

 - SearchObject.java

package client;


public class SearchObject 

{

	private String title;

	private String url;

	private String summary;

	

	public String getTitle() {

		return title;

	}

	public void setTitle(String title) {

		this.title = title;

	}

	public String getUrl() {

		return url;

	}

	public void setUrl(String url) {

		this.url = url;

	}

	public String getSummary() {

		return summary;

	}

	public void setSummary(String summary) {

		this.summary = summary;

	}

}

 - RSSReader.java

package client;


import java.net.URL;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;


import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;


import com.sun.syndication.feed.synd.SyndEntry;

import com.sun.syndication.feed.synd.SyndFeed;


public class RSSReader 

{

	private final Log log = LogFactory.getLog(this.getClass());

	private static final String SERVICE_URL = "http://blogrss.paran.com";

	private static final boolean USE_CACHE = true;

	

	private RSSApi rssApi;

	

	public RSSReader() throws Exception 

	{

		rssApi = new RSSApi(new URL(SERVICE_URL), USE_CACHE);

	}

  

	@SuppressWarnings("unchecked")

	public List<SearchObject> getFeedStories() 

	{

		List<SearchObject> results = null;

		List<SyndEntry> entries = null;

		Map<String,String> clients = null;

		

		try {

		clients = new HashMap<String,String>();

		clients.put("pmcid", "pmang");

		SyndFeed feed = rssApi.execute("RssView2.do", clients);

		entries = feed.getEntries();

		results = new ArrayList<SearchObject>();

		for (SyndEntry entry : entries) {

		SearchObject result = new SearchObject();

		result.setTitle(entry.getTitle());

		result.setUrl(entry.getLink());

		result.setSummary(entry.getDescription().getValue());

		results.add(result);

		}

		} catch (Exception e) {

			log.error(e);

		}

		return results;

	}

  

	public static void main(String[] args) 

	{

		RSSReader client = null;

		List<SearchObject> results = null;

		

		try {

		client = new RSSReader();

		results = client.getFeedStories();

		for (SearchObject result : results) {

		   System.out.println("TITLE:" + result.getTitle());

		   System.out.println("URL:" + result.getUrl());

		   System.out.println("SUMMARY:" + result.getSummary());

		   System.out.println("----------------------------------");

		}

		} catch (Exception e) {

			System.err.println(e.getMessage());

			throw new RuntimeException(e);

		}

	}

}

3. 실행 결과

이 프로그램을 응용하면 Bloglines같은 웹 기반의 RSS Reader 프로그램으로 확장할 수 있겠죠. 나중에 시간을 투자하여 한번 만들어 볼까 합니다.