VIVO-870 Make the number of threads configurable.

Also, clean up the shutdown process and some comments.

webapp/src/edu/cornell/mannlib/vitro/webapp/application/ApplicationImpl.java

@@ -210,9 +210,7 @@ public class ApplicationImpl implements Application {
 
 	@Override
 	public void shutdown() {
-		getFileStorage().shutdown(this);
+		// Nothing to do.
-		getImageProcessor().shutdown(this);
-		getSearchEngine().shutdown(this);
 	}
 
 	// ----------------------------------------------------------------------

webapp/src/edu/cornell/mannlib/vitro/webapp/application/ApplicationSetup.java

@@ -108,8 +108,6 @@ public class ApplicationSetup implements ServletContextListener {
 
 	@Override
 	public void contextDestroyed(ServletContextEvent sce) {
-		if (app != null) {
+		// Nothing to do.
-			app.shutdown();
-		}
 	}
 }

webapp/src/edu/cornell/mannlib/vitro/webapp/dao/filtering/filters/FilterByRoleLevelPermission.java

@@ -129,7 +129,7 @@ public class FilterByRoleLevelPermission extends VitroFiltersImpl {
 		/**
 		 * It would be nice if every ObjectPropertyStatement held a real
 		 * ObjectProperty. If it doesn't, we do the next best thing, but it
-		 * won't recognize any applicaable Faux properties.
+		 * won't recognize any applicable Faux properties.
 		 */
 		private ObjectProperty getOrCreateProperty(ObjectPropertyStatement ops) {
 			if (ops.getProperty() != null) {

webapp/src/edu/cornell/mannlib/vitro/webapp/searchindex/SearchIndexerImpl.java

@@ -59,6 +59,8 @@ import edu.cornell.mannlib.vitro.webapp.searchindex.tasks.UpdateStatementsTask;
 import edu.cornell.mannlib.vitro.webapp.searchindex.tasks.UpdateUrisTask;
 import edu.cornell.mannlib.vitro.webapp.utils.configuration.ConfigurationBeanLoader;
 import edu.cornell.mannlib.vitro.webapp.utils.configuration.ConfigurationBeanLoaderException;
+import edu.cornell.mannlib.vitro.webapp.utils.configuration.Property;
+import edu.cornell.mannlib.vitro.webapp.utils.configuration.Validation;
 import edu.cornell.mannlib.vitro.webapp.utils.developer.DeveloperSettings;
 import edu.cornell.mannlib.vitro.webapp.utils.threads.VitroBackgroundThread;
 import edu.cornell.mannlib.vitro.webapp.utils.threads.VitroBackgroundThread.WorkLevel;
@@ -73,6 +75,9 @@ import edu.cornell.mannlib.vitro.webapp.utils.threads.VitroBackgroundThread.Work
  * A thread pool is available so the tasks can create small units of work to be
  * run in parallel. Each task should block until all of its work units are
  * complete, to preserve the pattern of running one task at a time.
+ * 
+ * The number of threads in the thread pool is specified in the application
+ * setup file.
  */
 public class SearchIndexerImpl implements SearchIndexer {
 	private static final Log log = LogFactory.getLog(SearchIndexerImpl.class);
@@ -80,7 +85,9 @@ public class SearchIndexerImpl implements SearchIndexer {
 	private final ListenerList listeners = new ListenerList();
 	private final TaskQueue taskQueue = new TaskQueue();
 	private final Scheduler scheduler = new Scheduler(taskQueue);
-	private final WorkerThreadPool pool = new WorkerThreadPool();
+
+	private Integer threadPoolSize;
+	private WorkerThreadPool pool;
 
 	private ServletContext ctx;
 	private List<SearchIndexExcluder> excluders;
@@ -88,6 +95,27 @@ public class SearchIndexerImpl implements SearchIndexer {
 	private Set<IndexingUriFinder> uriFinders;
 	private WebappDaoFactory wadf;
 
+	@Property(uri = "http://vitro.mannlib.cornell.edu/ns/vitro/ApplicationSetup#threadPoolSize")
+	public void setThreadPoolSize(String size) {
+		if (threadPoolSize == null) {
+			threadPoolSize = Integer.parseInt(size);
+		} else {
+			throw new IllegalStateException(
+					"Configuration includes multiple values for threadPoolSize: "
+							+ threadPoolSize + ", and " + size);
+		}
+	}
+
+	@Validation
+	public void validate() throws Exception {
+		if (threadPoolSize == null) {
+			throw new IllegalStateException(
+					"Configuration did not include a value for threadPoolSize.");
+		} else {
+			this.pool = new WorkerThreadPool(threadPoolSize);
+		}
+	}
+
 	@Override
 	public void startup(Application application, ComponentStartupStatus ss) {
 		try {
@@ -442,9 +470,9 @@ public class SearchIndexerImpl implements SearchIndexer {
 	public static class WorkerThreadPool {
 		private final ThreadPoolExecutor pool;
 
-		public WorkerThreadPool() {
+		public WorkerThreadPool(int threadPoolSize) {
-			this.pool = new ThreadPoolExecutor(10, 10, 10, TimeUnit.SECONDS,
+			this.pool = new ThreadPoolExecutor(threadPoolSize, threadPoolSize,
-					new ArrayBlockingQueue<Runnable>(50),
+					10, TimeUnit.SECONDS, new ArrayBlockingQueue<Runnable>(50),
 					new VitroBackgroundThread.Factory(
 							"SearchIndexer_ThreadPool"));
 		}