ActiveMQDtdResolver xref

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    1   /***
    2    *
    3    * Copyright 2004 Protique Ltd
    4    *
    5    * Licensed under the Apache License, Version 2.0 (the "License");
    6    * you may not use this file except in compliance with the License.
    7    * You may obtain a copy of the License at
    8    *
    9    * http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   *
    17   **/
    18  package org.codehaus.activemq.spring;
    19
    20  import org.apache.commons.logging.Log;
    21  import org.apache.commons.logging.LogFactory;
    22  import org.springframework.core.io.ClassPathResource;
    23  import org.springframework.core.io.Resource;
    24  import org.xml.sax.EntityResolver;
    25  import org.xml.sax.InputSource;
    26
    27  import java.io.IOException;
    28
    29  /***
    30   * EntityResolver implementation for the ActiveMQ DTD,
    31   * to load the DTD from the ActiveMQ classpath JAR file.
    32   * <p/>
    33   * <p>Fetches "activemq.dtd" from the classpath resource
    34   * "/org/codehaus/activemq/activemq.dtd",
    35   * no matter if specified as some local URL or as
    36   * "http://activemq.codehaus.org/dtd/activemq.dtd".
    37   *
    38   * @version $Revision: 1.1 $
    39   */
    40  public class ActiveMQDtdResolver implements EntityResolver {
    41
    42      private static final String DTD_NAME = "activemq.dtd";
    43
    44      private static final String SEARCH_PACKAGE = "/org/codehaus/activemq/";
    45
    46      protected final Log logger = LogFactory.getLog(getClass());
    47
    48      public InputSource resolveEntity(String publicId, String systemId) throws IOException {
    49          logger.debug("Trying to resolve XML entity with public ID [" + publicId +
    50                  "] and system ID [" + systemId + "]");
    51          if (systemId != null && systemId.indexOf(DTD_NAME) > systemId.lastIndexOf("/")) {
    52
    53              String dtdFile = systemId.substring(systemId.indexOf(DTD_NAME));
    54              logger.debug("Trying to locate [" + dtdFile + "] under [" + SEARCH_PACKAGE + "]");
    55              try {
    56                  String name = SEARCH_PACKAGE + dtdFile;
    57                  Resource resource = new ClassPathResource(name, getClass());
    58                  InputSource source = new InputSource(resource.getInputStream());
    59                  source.setPublicId(publicId);
    60                  source.setSystemId(systemId);
    61                  logger.debug("Found beans DTD [" + systemId + "] in classpath");
    62                  return source;
    63              }
    64              catch (IOException ex) {
    65                  logger.debug("Could not resolve beans DTD [" + systemId + "]: not found in classpath", ex);
    66              }
    67          }
    68          // use the default behaviour -> download from website or wherever
    69          return null;
    70      }
    71
    72  }