Java tutorial
/* * Created on Aug 14, 2006 Copyright (C) 2001-6, Anthony Harrison anh23@pitt.edu * (jactr.org) This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of the License, * or (at your option) any later version. This library is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY; without even the * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See * the GNU Lesser General Public License for more details. You should have * received a copy of the GNU Lesser General Public License along with this * library; if not, write to the Free Software Foundation, Inc., 59 Temple * Place, Suite 330, Boston, MA 02111-1307 USA */ package org.jactr.core.module; import java.util.Collection; import java.util.Collections; import java.util.Map; import java.util.concurrent.Callable; import java.util.concurrent.Executor; import java.util.concurrent.Future; import java.util.concurrent.FutureTask; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.jactr.core.buffer.IActivationBuffer; import org.jactr.core.concurrent.ExecutorServices; import org.jactr.core.model.IModel; public abstract class AbstractModule implements IModule { /** * logger definition */ static public final Log LOGGER = LogFactory.getLog(AbstractModule.class); private IModel _model; private String _name; private Executor _executor = ExecutorServices.INLINE_EXECUTOR; public AbstractModule(String name) { _name = name; } /** * @param executor */ protected void setExecutor(Executor executor) { _executor = executor; } /** * default executor INLINE_EXECUTOR is used * * @return */ public Executor getExecutor() { return _executor; } public void dispose() { _model = null; } public IModel getModel() { return _model; } public String getName() { return _name; } public void install(IModel model) { _model = model; for (IActivationBuffer buffer : createBuffers()) _model.addActivationBuffer(buffer); } /** * called to create any buffers used by this buffer. They will be installed * into the model by the install(IModel) call * * @return */ protected Collection<IActivationBuffer> createBuffers() { return Collections.EMPTY_LIST; } public void uninstall(IModel model) { _model = null; } abstract public void initialize(); /** * return a safe, noncolliding name - calls to this should make sure that the * map is readlocked * * @param name * @param mapping * @return */ protected String getSafeName(String name, Map<String, ?> mapping) { if (!mapping.containsKey(name.toLowerCase())) return name; // does the oldName match the name-# pattern int lastIndex = -1; if ((lastIndex = name.lastIndexOf("-")) != -1) { String snippet = name.substring(lastIndex + 1, name.length()); try { /* * if snippet is a number, we cut it off */ Integer.parseInt(snippet); name = name.substring(0, lastIndex); } catch (NumberFormatException nfe) { } } StringBuilder sb = new StringBuilder(name); if (sb.charAt(sb.length() - 1) != '-') sb.append("-"); sb.append(mapping.size()); String rtn = sb.toString(); return rtn; } static public <T> Future<T> immediateReturn(T value) { FutureTask<T> ft = new FutureTask<T>(new Runnable() { public void run() { // noop } }, value); ft.run(); return ft; } /** * create a future task and execute it immediately using the INLINE_EXECUTOR * * @param <T> * @param caller * @return */ static public <T> Future<T> immediateFuture(Callable<T> caller) { return delayedFuture(caller, ExecutorServices.INLINE_EXECUTOR); } /** * create a future task and execute it on the exector * * @param <T> * @param caller * @param executor * @return */ static public <T> Future<T> delayedFuture(Callable<T> caller, Executor executor) { FutureTask<T> future = new FutureTask<T>(caller); if (executor != null) executor.execute(future); else future.run(); return future; } }