where to place DTD inside a package

Question

I have build a jar which contains a DTD file. I want to use this jar in an external application, in which the DTD file will be used for an XML file.

My question is how can i make my dtd file (which is inside .jar file) accessible from xml?

As we do in other config files of let's say struts hibernate etc, we define DTD in xml which are included in .jar files. I wanna do same in my jar file but not able to figure out the way, Please help.

Answer 1

You can implement an org.xml.sax.EntityResolver

public class MyResolver implements EntityResolver {

    public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
       if (systemId.contains("my.dtd")) {
           InputStream myDtdRes = getClass().getResourceAsStream("/com/yourcompany/my.dtd");
           return new InputSource(myDtdRes);
       } else {
           return null;
       }
    }
}

and use it with your DocumentBuilder.setEntityResolver()

 DocumentBuilder docBuilder = ...
 docBuilder.setEntityResolver(new MyResolver());

Answer 2

Here is the code snippets for you...

Add DTD To JAR

Use Resolver class for DTD to place DTD to your jar

DocumentBuilderFactory myFactory = xmlFactories.newDocumentBuilderFactory();
    myFactory.setNamespaceAware(true);
    myFactory.setValidating(false);
    DocumentBuilder db = myFactory.newDocumentBuilder();
    db.setEntityResolver(new EntityManager());



    public class EntityManager implements EntityResolver
    {
      public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
          /* returns contents of DTD */
      }

    }

Load DTD From JAR

InputStream ins = this.getClass().getResourceAsStream("project/mypackage/File.dtd");

So, now you have inputstream and you can use it as you like

Hope it helps you :)