01: /*
02: * Copyright (c) 1998-2008 Caucho Technology -- all rights reserved
03: *
04: * This file is part of Resin(R) Open Source
05: *
06: * Each copy or derived work must preserve the copyright notice and this
07: * notice unmodified.
08: *
09: * Resin Open Source is free software; you can redistribute it and/or modify
10: * it under the terms of the GNU General Public License as published by
11: * the Free Software Foundation; either version 2 of the License, or
12: * (at your option) any later version.
13: *
14: * Resin Open Source is distributed in the hope that it will be useful,
15: * but WITHOUT ANY WARRANTY; without even the implied warranty of
16: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
17: * of NON-INFRINGEMENT. See the GNU General Public License for more
18: * details.
19: *
20: * You should have received a copy of the GNU General Public License
21: * along with Resin Open Source; if not, write to the
22: * Free SoftwareFoundation, Inc.
23: * 59 Temple Place, Suite 330
24: * Boston, MA 02111-1307 USA
25: *
26: * @author Scott Ferguson
27: */
28:
29: package com.caucho.loader;
30:
31: import com.caucho.log.Log;
32: import com.caucho.util.L10N;
33:
34: import java.lang.ref.WeakReference;
35: import java.lang.reflect.Method;
36: import java.util.logging.Level;
37: import java.util.logging.Logger;
38:
39: /**
40: * Waits for the stop event and calls a stop() method.
41: */
42: public class WeakStopListener implements EnvironmentListener {
43: private static final L10N L = new L10N(WeakStopListener.class);
44: private static final Logger log = Log.open(WeakStopListener.class);
45:
46: private WeakReference<Object> _resourceRef;
47:
48: /**
49: * Creates the new stop listener.
50: *
51: * @param resource the resource which needs closing
52: */
53: public WeakStopListener(Object resource) {
54: _resourceRef = new WeakReference<Object>(resource);
55: }
56:
57: /**
58: * Handles the case where a class loader is activated.
59: */
60: public void environmentConfig(EnvironmentClassLoader loader) {
61: }
62:
63: /**
64: * Handles the case where a class loader is activated.
65: */
66: public void environmentStart(EnvironmentClassLoader loader) {
67: }
68:
69: /**
70: * Handles the case where a class loader is dropped.
71: */
72: public void environmentStop(EnvironmentClassLoader loader) {
73: Object resource = _resourceRef.get();
74: if (resource == null)
75: return;
76:
77: Method destroy = getStopMethod(resource.getClass());
78:
79: if (destroy == null)
80: return;
81:
82: try {
83: destroy.invoke(resource, (Object[]) null);
84: } catch (Throwable e) {
85: log.log(Level.WARNING, e.toString(), e);
86: }
87: }
88:
89: public static Method getStopMethod(Class cl) {
90: try {
91: return cl.getMethod("stop", new Class[0]);
92: } catch (Throwable e) {
93: }
94:
95: return null;
96: }
97: }
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