1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.fileupload.servlet;
18
19 import javax.servlet.ServletContext;
20 import javax.servlet.ServletContextEvent;
21 import javax.servlet.ServletContextListener;
22
23 import org.apache.commons.io.FileCleaningTracker;
24
25 /**
26 * A servlet context listener, which ensures that the
27 * {@link FileCleaningTracker}'s reaper thread is terminated,
28 * when the web application is destroyed.
29 */
30 public class FileCleanerCleanup implements ServletContextListener {
31
32 /**
33 * Attribute name, which is used for storing an instance of
34 * {@link FileCleaningTracker} in the web application.
35 */
36 public static final String FILE_CLEANING_TRACKER_ATTRIBUTE
37 = FileCleanerCleanup.class.getName() + ".FileCleaningTracker";
38
39 /**
40 * Returns the instance of {@link FileCleaningTracker}, which is
41 * associated with the given {@link ServletContext}.
42 *
43 * @param servletContext The servlet context to query
44 * @return The contexts tracker
45 */
46 public static FileCleaningTracker getFileCleaningTracker(final ServletContext servletContext) {
47 return (FileCleaningTracker) servletContext.getAttribute(FILE_CLEANING_TRACKER_ATTRIBUTE);
48 }
49
50 /**
51 * Sets the instance of {@link FileCleaningTracker}, which is
52 * associated with the given {@link ServletContext}.
53 *
54 * @param servletContext The servlet context to modify
55 * @param tracker The tracker to set
56 */
57 public static void setFileCleaningTracker(final ServletContext servletContext, final FileCleaningTracker tracker) {
58 servletContext.setAttribute(FILE_CLEANING_TRACKER_ATTRIBUTE, tracker);
59 }
60
61 /**
62 * Constructs a new instance.
63 */
64 public FileCleanerCleanup() {
65 // empty
66 }
67
68 /**
69 * Called when the web application is being destroyed.
70 * Calls {@link FileCleaningTracker#exitWhenFinished()}.
71 *
72 * @param sce The servlet context, used for calling
73 * {@link #getFileCleaningTracker(ServletContext)}.
74 */
75 @Override
76 public void contextDestroyed(final ServletContextEvent sce) {
77 getFileCleaningTracker(sce.getServletContext()).exitWhenFinished();
78 }
79
80 /**
81 * Called when the web application is initialized. Does
82 * nothing.
83 *
84 * @param sce The servlet context, used for calling
85 * {@link #setFileCleaningTracker(ServletContext, FileCleaningTracker)}.
86 */
87 @Override
88 public void contextInitialized(final ServletContextEvent sce) {
89 setFileCleaningTracker(sce.getServletContext(),
90 new FileCleaningTracker());
91 }
92
93 }