jaxb - how to map xsd files to URL to find them

Question

I have an xsd which has the typical import statements to import other xsd files but unfortunately, the references are hardcoded paths. Is there a way in JAXB to override the location of those imports using a xbj file?

All of these xsds are delivered via another jar(inside the jar) so I would like to get the one off the classpath and when it imports the others try to configure it so it gets the others off the classpath.

thanks, Dean

Answer 1

There's a number of techniques you can use to address the issue:

Catalogs

You can use a catalog file to override schema location. Here's a couple of examples:

Use another schema depending on the namespace:

PUBLIC "http://example.org/A" "others/schema_a.xsd"

Use another schema depending on the schema location:

REWRITE_SYSTEM "https://example.org/a.xsd" "others/schema_a.xsd"

Allows you to use a local copy of a schema file.

See this and this guides. Unfortunatelly, catalog support in XJC is not always working as expected and it's a bit hard to debug it.

Resolving schemas from Maven artifacts

If you're using Maven, you can use maven-jaxb2-plugin which can resolve schemas within Maven artifacts:

REWRITE_SYSTEM "https://example.org/a.xsd" "maven:org.example:a!/a.xsd"

In combination with catalogs, you can make JAXB use a.xsd inside a-XXX.jar instead of https://example.org/a.xsd.

See these sample projects:

• https://svn.java.net/svn/maven-jaxb2-plugin~svn/trunk/tests/catalog/
• https://svn.java.net/svn/maven-jaxb2-plugin~svn/trunk/tests/episodes/d/

Answer 2

You could try interacting with XJC programmatically (see below) and plug-in your own EntityResolver to resolve the XML schemas:

import com.sun.codemodel.*;
import com.sun.tools.xjc.*;
import com.sun.tools.xjc.api.*;

SchemaCompiler sc = XJC.createSchemaCompiler();
sc.setEntityResolver(new YourEntityResolver());
sc.setErrorListener(new YourErrorListener());
sc.parseSchema(SYSTEM_ID, element);
S2JJAXBModel model = sc.bind();

Below is a link to a related answer I gave that some people have found useful:

• https://stackoverflow.com/a/3489799/383861