001 /*
002 GRANITE DATA SERVICES
003 Copyright (C) 2011 GRANITE DATA SERVICES S.A.S.
004
005 This file is part of Granite Data Services.
006
007 Granite Data Services is free software; you can redistribute it and/or modify
008 it under the terms of the GNU Library General Public License as published by
009 the Free Software Foundation; either version 2 of the License, or (at your
010 option) any later version.
011
012 Granite Data Services is distributed in the hope that it will be useful, but
013 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
014 FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
015 for more details.
016
017 You should have received a copy of the GNU Library General Public License
018 along with this library; if not, see <http://www.gnu.org/licenses/>.
019 */
020
021 package org.granite.tide.util;
022
023 import java.lang.reflect.Method;
024 import java.util.ArrayList;
025 import java.util.HashMap;
026 import java.util.List;
027 import java.util.Map;
028 import java.util.Set;
029
030 import org.granite.logging.Logger;
031 import org.granite.tide.invocation.ContextEvent;
032
033 /**
034 * @author Franck WOLFF
035 */
036 public abstract class AbstractContext extends HashMap<String, Object> {
037
038 private static final long serialVersionUID = 1L;
039 private static final Logger log = Logger.getLogger(AbstractContext.class);
040 private static final ThreadLocal<AbstractContext> contexts = new ThreadLocal<AbstractContext>();
041
042 private final Map<String, Set<Method>> observers;
043 private final List<ContextEvent> remoteEvents;
044
045 protected AbstractContext(Map<String, Set<Method>> observers) {
046 synchronized (contexts) {
047 if (contexts.get() != null)
048 throw new IllegalStateException("Context already created");
049
050 this.observers = observers;
051 this.remoteEvents = new ArrayList<ContextEvent>();
052
053 contexts.set(this);
054 }
055 }
056
057 public List<ContextEvent> getRemoteEvents() {
058 return remoteEvents;
059 }
060
061 protected abstract Set<String> getRemoteObservers();
062 protected abstract Object callMethod(Method method, Object... args) throws Exception;
063
064 public static AbstractContext instance() {
065 return contexts.get();
066 }
067
068 public static void raiseEvent(String name, Object... args) {
069 AbstractContext instance = instance();
070 Map<String, Set<Method>> observers = instance.observers;
071 if (observers.containsKey(name)) {
072 for (Method method : observers.get(name)) {
073 try {
074 instance.callMethod(method, args);
075 }
076 catch (Exception e) {
077 log.error(e, "Could not call method: %s", method);
078 }
079 }
080 }
081 Set<String> remoteObservers = instance.getRemoteObservers();
082 if (remoteObservers.contains(name))
083 instance.remoteEvents.add(new ContextEvent(name, args));
084 }
085
086 public static void remove() {
087 AbstractContext context = contexts.get();
088 if (context != null) {
089 try {
090 context.clear();
091 context.remoteEvents.clear();
092 }
093 finally {
094 contexts.remove();
095 }
096 }
097 }
098 }