From ea810d645605a8f7cdcacdf828f839a85ebe9c21 Mon Sep 17 00:00:00 2001
From: =?utf8?q?David=20=E2=80=98Bombe=E2=80=99=20Roden?=
 <bombe@pterodactylus.net>
Date: Mon, 9 Mar 2009 18:01:56 +0100
Subject: [PATCH] Stub implementation of page fetching.

---
 src/net/pterodactylus/arachne/core/Core.java | 71 ++++++++++++++++++++++++++--
 1 file changed, 68 insertions(+), 3 deletions(-)

diff --git a/src/net/pterodactylus/arachne/core/Core.java b/src/net/pterodactylus/arachne/core/Core.java
index f3fd5de..ad438b1 100644
--- a/src/net/pterodactylus/arachne/core/Core.java
+++ b/src/net/pterodactylus/arachne/core/Core.java
@@ -6,10 +6,14 @@ package net.pterodactylus.arachne.core;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 import de.ina.util.service.AbstractService;
+import de.ina.util.thread.DumpingThreadFactory;
 import de.ina.util.validation.Validation;
 
 /**
@@ -19,6 +23,9 @@ import de.ina.util.validation.Validation;
  */
 public class Core extends AbstractService {
 
+	/** The logger. */
+	private static final Logger logger = Logger.getLogger(Core.class.getName());
+
 	//
 	// PROPERTIES
 	//
@@ -33,8 +40,11 @@ public class Core extends AbstractService {
 	// INTERNAL MEMBERS
 	//
 
+	/** Thread pool for the URL fetches. */
+	private Executor urlFetcherExecutor = Executors.newFixedThreadPool(1, new DumpingThreadFactory("URLFetcher-"));
+
 	/** The current list of URLs to crawl. */
-	private final List<Page> pages = Collections.synchronizedList(new ArrayList<Page>());
+	private final List<Page> pages = new ArrayList<Page>();
 
 	//
 	// ACTIONS
@@ -108,6 +118,44 @@ public class Core extends AbstractService {
 	}
 
 	//
+	// SERVICE METHODS
+	//
+
+	/**
+	 * {@inheritdoc}
+	 *
+	 * @see de.ina.util.service.AbstractService#serviceRun()
+	 */
+	@Override
+	protected void serviceRun() {
+		while (!shouldStop()) {
+			Page nextPage = null;
+			synchronized (syncObject) {
+				while (!shouldStop() && pages.isEmpty()) {
+					try {
+						syncObject.wait();
+					} catch (InterruptedException ie1) {
+						/* ignore. */
+					}
+				}
+				if (!shouldStop()) {
+					nextPage = pages.remove(0);
+				}
+			}
+			if (shouldStop()) {
+				break;
+			}
+			URL nextURL = createURL(nextPage);
+			if (nextURL == null) {
+				logger.log(Level.INFO, "Skipping “" + nextPage + "”.");
+				continue;
+			}
+			URLFetcher urlFetcher = new URLFetcher(this, nextURL);
+			urlFetcherExecutor.execute(urlFetcher);
+		}
+	}
+
+	//
 	// PRIVATE METHODS
 	//
 
@@ -123,7 +171,7 @@ public class Core extends AbstractService {
 	 * @return The joined path
 	 */
 	private String createPath(String[] pathComponents, int index) {
-		Validation.begin().isNotNull("pathComponents", pathComponents).check().isLess("index", pathComponents.length, index).check();
+		Validation.begin().isNotNull("pathComponents", pathComponents).check().isLess("index", index, pathComponents.length).check();
 		StringBuilder path = new StringBuilder();
 		for (int pathComponentIndex = index; pathComponentIndex < pathComponents.length; pathComponentIndex++) {
 			if (path.length() > 0) {
@@ -134,4 +182,21 @@ public class Core extends AbstractService {
 		return path.toString();
 	}
 
+	/**
+	 * Creates a URL from the given page.
+	 *
+	 * @param page
+	 *            The page to create a URL from
+	 * @return The created URL, or <code>null</code> if the URL could not be
+	 *         created
+	 */
+	private URL createURL(Page page) {
+		try {
+			return new URL("http://" + nodeHost + ":" + nodePort + "/");
+		} catch (MalformedURLException mue1) {
+			/* nearly impossible. */
+		}
+		return null;
+	}
+
 }
-- 
2.7.4