import java.net.URL;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
+import java.util.HashSet;
import java.util.List;
+import java.util.Set;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.logging.Level;
private ParserFactory parserFactory = new ParserFactory();
/** Thread pool for the URL fetches. */
- private Executor urlFetcherExecutor = Executors.newFixedThreadPool(1, new DumpingThreadFactory("URLFetcher-"));
+ private Executor urlFetcherExecutor = Executors.newSingleThreadExecutor(new DumpingThreadFactory("URLFetcher-"));
/** The current list of URLs to crawl. */
private final List<Page> pages = new ArrayList<Page>();
+ /** Already crawled pages. */
+ private final Set<Page> crawledPages = new HashSet<Page>();
+
//
// ACCESSORS
//
*/
public void addPage(Page page) {
Validation.begin().isNotNull("page", page).check();
- pages.add(page);
- notifySyncObject();
+ if (!crawledPages.contains(page) && !pages.contains(page)) {
+ pages.add(page);
+ notifySyncObject();
+ }
}
//
* @see de.ina.util.service.AbstractService#serviceRun()
*/
@Override
- @SuppressWarnings("null")
protected void serviceRun() {
while (!shouldStop()) {
- Page nextPage = null;
+ final Page nextPage;
+ Page page = null;
synchronized (syncObject) {
while (!shouldStop() && pages.isEmpty()) {
try {
}
}
if (!shouldStop()) {
- nextPage = pages.remove(0);
+ page = pages.remove(0);
}
}
if (shouldStop()) {
break;
}
+ nextPage = page;
URL nextURL = nextPage.toURL(nodeHost, nodePort);
if (nextURL == null) {
logger.log(Level.INFO, "Skipping “" + nextPage + "”.");
urlFetcher = new URLFetcher(parserFactory, nextURL);
urlFetcherExecutor.execute(new Runnable() {
+ @SuppressWarnings("synthetic-access")
public void run() {
urlFetcher.run();
+ crawledPages.add(nextPage);
for (Page page : urlFetcher.getCollectedPages()) {
addPage(page);
}