1 /**
2 * This file Copyright (c) 2012 Magnolia International
3 * Ltd. (http://www.magnolia-cms.com). All rights reserved.
4 *
5 *
6 * This file is dual-licensed under both the Magnolia
7 * Network Agreement and the GNU General Public License.
8 * You may elect to use one or the other of these licenses.
9 *
10 * This file is distributed in the hope that it will be
11 * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12 * implied warranty of MERCHANTABILITY or FITNESS FOR A
13 * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14 * Redistribution, except as permitted by whichever of the GPL
15 * or MNA you select, is prohibited.
16 *
17 * 1. For the GPL license (GPL), you can redistribute and/or
18 * modify this file under the terms of the GNU General
19 * Public License, Version 3, as published by the Free Software
20 * Foundation. You should have received a copy of the GNU
21 * General Public License, Version 3 along with this program;
22 * if not, write to the Free Software Foundation, Inc., 51
23 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24 *
25 * 2. For the Magnolia Network Agreement (MNA), this file
26 * and the accompanying materials are made available under the
27 * terms of the MNA which accompanies this distribution, and
28 * is available at http://www.magnolia-cms.com/mna.html
29 *
30 * Any modifications to this file must keep this entire header
31 * intact.
32 *
33 */
34 package info.magnolia.module.observation.commands;
35
36 import info.magnolia.context.Context;
37 import info.magnolia.context.MgnlContext;
38 import info.magnolia.context.SimpleContext;
39
40 import java.util.ArrayList;
41 import java.util.List;
42 import java.util.Map;
43
44 import javax.jcr.RepositoryException;
45 import javax.jcr.observation.Event;
46 import javax.jcr.observation.EventIterator;
47 import javax.jcr.observation.EventListener;
48
49 import org.apache.commons.chain.Command;
50 import org.slf4j.Logger;
51 import org.slf4j.LoggerFactory;
52
53 /**
54 * This is a eventListener wrapper for the commands to be executed when an event occurs.
55 *
56 * @author tmiyar
57 *
58 */
59 public class CommandEventListener implements EventListener {
60 private static final Logger log = LoggerFactory.getLogger(CommandEventListener.class);
61
62 // command configuration
63 private Command command;
64
65 // optional some commands need to get the params through this map
66 private Map params;
67
68 /**
69 * Implementation of the onEvent method that will execute the defined command.
70 */
71 public void onEvent(EventIterator events) {
72
73 log.debug("Checking event for command {} invocation", this.command.getClass().getName());
74
75 Event event;
76 List paths = new ArrayList();
77 String path = null;
78
79 // initialize context
80 Context ctx;
81 if (MgnlContext.hasInstance()) {
82 ctx = MgnlContext.getInstance();
83 } else {
84
85 ctx = new SimpleContext(MgnlContext.getSystemContext()) {
86 @Override
87 public void release() {
88 // release is done on system context
89 }
90 };
91 }
92
93 MgnlContext.setInstance(ctx);
94 try {
95 while (events.hasNext()) {
96 try {
97 event = events.nextEvent();
98 if (checkIfEventIsProcessed(event)) {
99 // if the path already exists do not execute the command
100 // again
101 path = getPath(event);
102 if (path == null || paths.contains(path)) {
103 continue;
104 } else {
105 paths.add(path);
106 }
107
108 Context executionCtx = new SimpleContext();
109
110 try {
111 if (params != null) {
112 executionCtx.putAll(params);
113 }
114 executionCtx.put(Context.ATTRIBUTE_PATH, path);
115
116 try {
117 command.execute(executionCtx);
118 log.debug("Successfully executed command {}", command.getClass().getName());
119 } catch (Exception e) {
120 log.error("can't execute command ", e);
121 }
122 } finally {
123 // We can't release this context because it
124 // delegates the release to the main context which
125 // we still use for further executions
126 // executionCtx.release();
127 }
128 }
129 } catch (Exception e) {
130 log.error("can't deliver event", e);
131 }
132 }
133 } finally {
134 // MgnlContext.release();
135 }
136 }
137
138 protected boolean checkIfEventIsProcessed(Event event)
139 throws RepositoryException {
140 return !event.getPath().startsWith("/jcr:system");
141 }
142
143 protected String getPath(Event event) throws RepositoryException {
144 return event.getPath();
145 }
146
147 public Command getCommand() {
148 return command;
149 }
150
151 public void setCommand(Command command) {
152 this.command = command;
153 }
154
155 public Map getParams() {
156 return params;
157 }
158
159 public void setParams(Map params) {
160 this.params = params;
161 }
162
163 }