1 /*
2 * Copyright 2007 Joachim Grueneis
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5 * in compliance with the License. You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software distributed under the License
10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
11 * or implied. See the License for the specific language governing permissions and limitations under
12 * the License.
13 */
14 package org.exolab.castor.xml.util.resolvers;
15
16 import java.util.Map;
17
18 import org.apache.commons.logging.Log;
19 import org.apache.commons.logging.LogFactory;
20 import org.exolab.castor.xml.ResolverException;
21 import org.exolab.castor.xml.util.ResolverClassCommand;
22 import org.exolab.castor.xml.util.ResolverStrategy;
23
24 /**
25 * The abstract resolver command provides the argument checking, writes a debug message and reads
26 * the class loader from the properties... All specific code is found in the extended classes.
27 *
28 * @author Joachim Grueneis, jgrueneis AT gmail DOT com
29 * @version $Id$
30 * @since 1.2
31 */
32 public abstract class AbstractResolverClassCommand implements ResolverClassCommand {
33 private static final Log LOG = LogFactory.getLog(AbstractResolverClassCommand.class);
34
35 /**
36 * {@inheritDoc}
37 */
38 public final Map resolve(final String className, final Map properties) throws ResolverException {
39 if ((className == null) || ("".equals(className))) {
40 String message = "No class to resolve specified";
41 LOG.warn(message);
42 throw new IllegalArgumentException(message);
43 }
44
45 if (LOG.isDebugEnabled()) {
46 LOG.debug("Now in method: " + this.getClass().getName() + " resolving: " + className);
47 }
48
49 ClassLoader classLoader = (ClassLoader) properties.get(ResolverStrategy.PROPERTY_CLASS_LOADER);
50 return this.internalResolve(className, classLoader, properties);
51 }
52
53 /**
54 * The required parameter checks are in the public method and here we expect that the resolve
55 * logic itself is implemented.
56 *
57 * @param className the name of the class to resolve
58 * @param classLoader the class loader to use
59 * @param props the resolve properties to use
60 * @return a Map of className and XMLClassDescriptor
61 * @throws ResolverException if unrecoverable problems in resolve occured
62 */
63 protected abstract Map internalResolve(String className, ClassLoader classLoader, Map props)
64 throws ResolverException;
65 }