You can load schemata quite easily with Xerces:

1. Just import the right classes:

   import org.apache.xerces.util.*;
   import org.apache.xerces.xs.*;
   import org.apache.xerces.impl.xs.XMLSchemaLoader;

2. Instantiate the XSLoader implementation:

   XMLSchemaLoader loader = new XMLSchemaLoader();
   

3. Setup the catalog:

   String [] catalogs = { "catalog.xml" };
   XMLCatalogResolver resolver = new XMLCatalogResolver(catalogs);
   loader.setEntityResolver(resolver);

4. Load the schema:

   XSModel model = loader.loadURI(new File("myschema.xsd").toURI().toString());

For example, list all the types:

XSNamedMap map = model.getComponents(XSConstants.TYPE_DEFINITION);
for (int j=0; j<map.getLength(); j++) {
   XSObject o = map.item(j);
   System.out.println("{"+o.getNamespace()+"}"+o.getName());
}

You can browse the javadoc for the package org.apache.xerces.xs at the apache website.