package org.lcsim.util.cache;
   
   import java.io.File;
   import java.io.FileInputStream;
   import java.io.IOException;
   import java.net.URL;
   import org.xml.sax.EntityResolver;
   import org.xml.sax.InputSource;
   import org.xml.sax.SAXException;
  
  /**
   * An entity resolver which caches schemas locally. This makes it possible to
   * run the tests without a network connection, provided the cache has been
   * previously seeded.
   * @author tonyj
   * @version $Id: CachingEntityResolver.java,v 1.1.1.1 2010/01/25 22:23:07 jeremy
   *          Exp $
   */
  public class CachingEntityResolver implements EntityResolver {
      private FileCache fileCache;
  
      public CachingEntityResolver() throws IOException {
          fileCache = new FileCache();
      }
  
      public CachingEntityResolver(File cacheDirectory) throws IOException {
          fileCache = new FileCache(cacheDirectory);
      }
  
      public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
          File file = fileCache.getCachedFile(new URL(systemId));
          InputSource result = new InputSource(new FileInputStream(file));
          result.setSystemId(systemId);
          return result;
      }
  }