1 /**
2 * This file Copyright (c) 2016 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.config.source;
35
36 import info.magnolia.config.registry.DefinitionProvider;
37 import info.magnolia.config.registry.DefinitionProviderWrapper;
38
39 import java.lang.reflect.Method;
40
41 import org.slf4j.Logger;
42 import org.slf4j.LoggerFactory;
43
44 import com.thoughtworks.proxy.factory.CglibProxyFactory;
45 import com.thoughtworks.proxy.toys.decorate.Decorating;
46 import com.thoughtworks.proxy.toys.decorate.Decorator;
47
48 /**
49 * Encourages {@link #get()} method implementation in such a way that it's result uses a 'decorated super-result' as a
50 * safety net for unsuccessful method calls.
51 *
52 * @param <T> the decorated definition type
53 */
54 public abstract class DefinitionProviderWrapperWithProxyFallback<T> extends DefinitionProviderWrapper<T> {
55
56 private static final Logger log = LoggerFactory.getLogger(DefinitionProviderWrapperWithProxyFallback.class);
57
58 public DefinitionProviderWrapperWithProxyFallback(DefinitionProvider<T> delegate) {
59 super(delegate);
60 }
61
62 @Override
63 public final T get() {
64 final T decoratedBean = doGet();
65
66 if (decoratedBean == null) {
67 return null;
68 }
69
70 return Decorating.proxy(decoratedBean).visiting(new Decorator<T>() {
71 @Override
72 public Object decorateResult(T proxy, Method method, Object[] args, Object result) {
73 if (result == null) {
74 try {
75 return method.invoke(getDelegate().get());
76 } catch (ReflectiveOperationException e) {
77 log.debug("Failed to invoke fallback method call due to a reflection operation problem: {}", method.toString(), e.getMessage());
78 } catch (Exception e) {
79 log.debug("Failed to invoke fallback method call due to: {}", method.toString(), e.getMessage());
80 }
81 }
82 return super.decorateResult(proxy, method, args, result);
83 }
84 }).build(new CglibProxyFactory());
85 }
86
87 protected abstract T doGet();
88 }