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1   /**
2    *  Copyright 2003-2006 Greg Luck
3    *
4    *  Licensed under the Apache License, Version 2.0 (the "License");
5    *  you may not use this file except in compliance with the License.
6    *  You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   *  Unless required by applicable law or agreed to in writing, software
11   *  distributed under the License is distributed on an "AS IS" BASIS,
12   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   *  See the License for the specific language governing permissions and
14   *  limitations under the License.
15   */
16  
17  package net.sf.ehcache.config;
18  
19  import net.sf.ehcache.CacheException;
20  import net.sf.ehcache.util.ClassLoaderUtil;
21  import org.apache.commons.logging.Log;
22  import org.apache.commons.logging.LogFactory;
23  
24  import javax.xml.parsers.SAXParser;
25  import javax.xml.parsers.SAXParserFactory;
26  import java.io.BufferedInputStream;
27  import java.io.File;
28  import java.io.FileInputStream;
29  import java.io.IOException;
30  import java.io.InputStream;
31  import java.net.URL;
32  
33  /**
34   * A utility class which configures beans from XML, using reflection.
35   *
36   * @author Greg Luck
37   * @version $Id: ConfigurationFactory.java 52 2006-04-24 14:50:03Z gregluck $
38   */
39  public final class ConfigurationFactory {
40      private static final Log LOG = LogFactory.getLog(ConfigurationFactory.class.getName());
41  
42      private static final String DEFAULT_CLASSPATH_CONFIGURATION_FILE = "/ehcache.xml";
43      private static final String FAILSAFE_CLASSPATH_CONFIGURATION_FILE = "/ehcache-failsafe.xml";
44  
45      /**
46       * Constructor.
47       */
48      private ConfigurationFactory() {
49  
50      }
51  
52      /**
53       * Configures a bean from an XML file.
54       */
55      public static Configuration parseConfiguration(final File file) throws CacheException {
56          if (file == null) {
57              throw new CacheException("Attempt to configure ehcache from null file.");
58          }
59  
60          if (LOG.isDebugEnabled()) {
61              LOG.debug("Configuring ehcache from file: " + file.toString());
62          }
63          Configuration configuration = null;
64          InputStream input = null;
65          try {
66              input = new BufferedInputStream(new FileInputStream(file));
67              configuration = parseConfiguration(input);
68          } catch (Exception e) {
69              throw new CacheException("Error configuring from " + file + ". Initial cause was " + e.getMessage(), e);
70          } finally {
71              try {
72                  if (input != null) {
73                      input.close();
74                  }
75              } catch (IOException e) {
76                  LOG.error("IOException while closing configuration input stream. Error was " + e.getMessage());
77              }
78          }
79          return configuration;
80      }
81  
82      /**
83       * Configures a bean from an XML file available as an URL.
84       */
85      public static Configuration parseConfiguration(final URL url) throws CacheException {
86          if (LOG.isDebugEnabled()) {
87              LOG.debug("Configuring ehcache from URL: " + url);
88          }
89          Configuration configuration;
90          InputStream input = null;
91          try {
92              input = url.openStream();
93              configuration = parseConfiguration(input);
94          } catch (Exception e) {
95              throw new CacheException("Error configuring from " + url + ". Initial cause was " + e.getMessage(), e);
96          } finally {
97              try {
98                  if (input != null) {
99                      input.close();
100                 }
101             } catch (IOException e) {
102                 LOG.error("IOException while closing configuration input stream. Error was " + e.getMessage());
103             }
104         }
105         return configuration;
106     }
107 
108     /**
109      * Configures a bean from an XML file in the classpath.
110      */
111     public static Configuration parseConfiguration() throws CacheException {
112         ClassLoader standardClassloader = ClassLoaderUtil.getStandardClassLoader();
113         URL url = null;
114         if (standardClassloader != null) {
115             url = standardClassloader.getResource(DEFAULT_CLASSPATH_CONFIGURATION_FILE);
116         }
117         if (url == null) {
118             url = ConfigurationFactory.class.getResource(DEFAULT_CLASSPATH_CONFIGURATION_FILE);
119         }
120         if (url != null) {
121             if (LOG.isDebugEnabled()) {
122                 LOG.debug("Configuring ehcache from ehcache.xml found in the classpath: " + url);
123             }
124         } else {
125             url = ConfigurationFactory.class.getResource(FAILSAFE_CLASSPATH_CONFIGURATION_FILE);
126             if (LOG.isWarnEnabled()) {
127                 LOG.warn("No configuration found. Configuring ehcache from ehcache-failsafe.xml "
128                         + " found in the classpath: " + url);
129             }
130         }
131         return parseConfiguration(url);
132     }
133 
134     /**
135      * Configures a bean from an XML input stream.
136      */
137     public static Configuration parseConfiguration(final InputStream inputStream) throws CacheException {
138         if (LOG.isDebugEnabled()) {
139             LOG.debug("Configuring ehcache from InputStream");
140         }
141         Configuration configuration = new Configuration();
142         try {
143             final SAXParser parser = SAXParserFactory.newInstance().newSAXParser();
144             final BeanHandler handler = new BeanHandler(configuration);
145             parser.parse(inputStream, handler);
146         } catch (Exception e) {
147             throw new CacheException("Error configuring from input stream. Initial cause was " + e.getMessage(), e);
148         }
149         return configuration;
150     }
151 
152 }