/**
    * Copyright 2005-2011 The Kuali Foundation
    *
    * Licensed under the Educational Community License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    * http://www.opensource.org/licenses/ecl2.php
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.kuali.rice.ken.util;
  
  import java.io.InputStream;
  
  import javax.xml.XMLConstants;
  import javax.xml.parsers.DocumentBuilder;
  import javax.xml.parsers.DocumentBuilderFactory;
  
  import org.w3c.dom.DOMImplementation;
  import org.w3c.dom.ls.DOMImplementationLS;
  import org.w3c.dom.ls.LSInput;
  import org.w3c.dom.ls.LSResourceResolver;
  
  /**
   * Resource resolver for SchemaFactory.  For now used during validation of NotificationRequest content element.
   * Looks up XSD from classloader.
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class ClassLoaderLSResourceResolver extends ClassLoaderResourceResolver implements LSResourceResolver {
      /**
       * Constructs a ClassLoaderLSResourceResolver.java.
       * @param base
       * @param prefix
       */
      public ClassLoaderLSResourceResolver(String base, String prefix) {
          super(base, prefix);
      }
  
      /**
       * @see org.w3c.dom.ls.LSResourceResolver#resolveResource(java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String)
       */
      public LSInput resolveResource(String type, String namespaceURI, String publicId, String systemId, String baseURI) {
          if (!type.equals(XMLConstants.W3C_XML_SCHEMA_NS_URI)) {
              return null;
          }
          LOG.error(type);
          LOG.error(namespaceURI);
          LOG.error(publicId);
          LOG.error(systemId);
          LOG.error(baseURI);
          String path = resolveSystemId(systemId);
          if (path == null) {
              return null;
          }
          LOG.debug("Looking up resource '" + path + "' for system id '" + systemId + "'");
          InputStream is = getClass().getClassLoader().getResourceAsStream(path);
          if (is == null) {
              String message = "Unable to find schema (" + path + ") for: " + systemId;
              LOG.error(message);
              throw new RuntimeException/*SAXException*/(message);
          }
          try {
              DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
              DocumentBuilder builder = factory.newDocumentBuilder();
              DOMImplementation domImpl = builder.getDOMImplementation();
              DOMImplementationLS dils = (DOMImplementationLS) domImpl;
              LSInput input = dils.createLSInput();
              input.setByteStream(is);
              return input;
          } catch (Exception e) {
              throw new RuntimeException(e);
          }
      }
  }