package org.kuali.core.db.torque;

 import java.io.IOException;

 import org.apache.torque.engine.database.transform.DTDResolver;

 import org.springframework.core.io.DefaultResourceLoader;

 import org.springframework.core.io.Resource;

 import org.springframework.core.io.ResourceLoader;

 import org.xml.sax.InputSource;

 import org.xml.sax.SAXException;

 /**

  * Kuali customized Torque's database.dtd by adding sequence and view. Thus we need to use our custom dtd instead of the

  * latest one from Torque. At the moment the Kuali database.dtd is stored in many different spots inside Subversion.

  * This is because the impex was not set up such that XML parsing/generation was able to read Kuali's customized

  * database.dtd off of the classpath. Thus, database.dtd has to be present on the file system in the same directory as

  * any schema.xml files that are being parsed.

  * 

  * This class allows a single copy of database.dtd to be bundled into a .jar and shared by everyone at Kuali.

  */

 public class ImpexDTDResolver extends DTDResolver {

         public static final String DTD_NAME = "database.dtd";

         public static final String DTD_LOCATION = "http://www.kuali.org/dtd/" + DTD_NAME;

         public ImpexDTDResolver() throws SAXException {

                 super();

         }

         @Override

         public InputSource resolveEntity(String publicId, String systemId) throws IOException, SAXException {

                 if (DTD_LOCATION.equals(systemId)) {

                         ResourceLoader loader = new DefaultResourceLoader();

                         Resource resource = loader.getResource("classpath:" + DTD_NAME);

                         return new InputSource(resource.getInputStream());

                 } else {

                         return super.resolveEntity(publicId, systemId);

                 }

         }

 }