1 /**
2 * This file Copyright (c) 2010-2017 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.groovy.support.classes;
35
36 import info.magnolia.context.Context;
37 import info.magnolia.objectfactory.ClassFactory;
38 import info.magnolia.objectfactory.DefaultClassFactory;
39 import info.magnolia.objectfactory.ReloadableClassFactory;
40
41 import org.codehaus.groovy.control.CompilationFailedException;
42 import org.slf4j.Logger;
43 import org.slf4j.LoggerFactory;
44
45 import groovy.lang.GroovyClassLoader;
46 import groovy.lang.GroovyObject;
47
48 /**
49 * A {@link info.magnolia.objectfactory.ClassFactory} which attempts to load classes using a
50 * {@link groovy.lang.GroovyClassLoader} if they were not found using a delegate (which is a
51 * {@link info.magnolia.objectfactory.DefaultClassFactory} by default).
52 *
53 * <p>A little bit of background:<br>
54 * When loading classes via the GroovyClassLoader, we loose control on where classes
55 * are loaded from. The GroovyClassLoader will always first attempt to load any given
56 * class via its parent*. This is actually the expected behaviour from regular ClassLoader
57 * implementations. As long as we first try loading our classes via the DefaultClassFactory,
58 * we're fine, we keep control of the order in which ClassLoaders are poked for classes.
59 * By default, the GroovyClassLoader uses the current thread's ContextClassLoader, while
60 * we first use the caller's ClassLoader, *then* the thread's.<br>
61 * Any class/script loaded via the GroovyClassLoader and using classes that haven't been
62 * loaded yet will thus see those classes loaded via the current thread's ContextClassLoader.
63 * If this were to become an issue, we'd probably need to create something along the lines of
64 * a ClassFactoryAwareClassLoader, and give that as a parent to the GroovyClassLoader.</p>
65 */
66 public class GroovyClassFactory implements ReloadableClassFactory {
67 private final static Logger log = LoggerFactory.getLogger(GroovyClassFactory.class);
68
69 private final ClassFactory delegate;
70 private final GroovyClassLoader gcl;
71
72 public GroovyClassFactory() {
73 // Using the SystemContext to load classes of the repository, by default.
74 // Since the forName() method will attempt to load any class via the DefaultClassFactory *first*,
75 // we should hopefully have a SystemContext implementation ready by the time we need to access the repository.
76 // (and the repository should be ready by then too)
77 this(new DefaultClassFactory());
78 }
79
80 public GroovyClassFactory(ClassFactory delegate) {
81 this.delegate = delegate;
82 this.gcl = new MgnlGroovyClassLoader();
83 }
84
85 /**
86 * @deprecated since 2.4.4 please use {@link #GroovyClassFactory()} instead.
87 */
88 @Deprecated
89 public GroovyClassFactory(ClassFactory delegate, Context context) {
90 this(delegate);
91 }
92
93 @Override
94 public <C> Class<C> forName(String className) throws ClassNotFoundException {
95 try {
96 return delegate.forName(className);
97 } catch (ClassNotFoundException e) {
98 try {
99 return gcl.loadClass(className, true, false);
100 } catch (CompilationFailedException compilationException) {
101 // TODO - would be nice to get the precise location of the source script ...
102 log.error("Could not compile {} with Groovy:\n{}", className, compilationException.getMessage());
103 throw new ClassNotFoundException("Could not compile " + className + " with Groovy", compilationException);
104 }
105 }
106 }
107
108 @Override
109 public <T> T newInstance(Class<T> c, Object... objects) {
110 final Class<T> klass = recompileClassIfNeeded(c);
111 return delegate.newInstance(klass, objects);
112 }
113
114 @Override
115 public <T> T newInstance(Class<T> c, Class<?>[] argTypes, Object... params) {
116 final Class<T> klass = recompileClassIfNeeded(c);
117 return delegate.newInstance(klass, argTypes, params);
118 }
119
120 // TODO - shouldn't this move to the ResourceLoader ?
121 private <T> Class<T> recompileClassIfNeeded(Class<T> c) {
122 Class<T> klass = c;
123 if (GroovyObject.class.isAssignableFrom(c)) {
124 log.debug("{} is a Groovy object, so check if a newer source is available", c.getName());
125 try {
126 klass = gcl.loadClass(c.getName(), true, false);
127 } catch (ClassNotFoundException e) {
128 log.warn(e.getMessage());
129 klass = c;
130 }
131 }
132 return klass;
133 }
134
135 @Override
136 public <T> Class<T> reload(Class<T> c) throws ClassNotFoundException {
137 return recompileClassIfNeeded(c);
138 }
139 }