Red Hat Summit Red Hat SummitSupportConsoleDevelopersStart a trialContact

15.6.2. Registering a Transformer via Annotations

The key for each value must also be indexed, and the key instance must then be transformed in a String.
JBoss Data Grid includes some default transformation routines for encoding common primitives, however to use a custom key you must provide an implementation of org.infinispan.query.Transformer.
The following example shows how to annotate your key type using org.infinispan.query.Transformer: 
@Transformable(transformer = CustomTransformer.class)
public class CustomKey {
   ...
}
 
public class CustomTransformer implements Transformer {
   @Override
   public Object fromString(String s) {
      ...
      return new CustomKey(...);
   }
 
   @Override
   public String toString(Object customType) {
      CustomKey ck = (CustomKey) customType;
      return ...
   }
}
Copy to Clipboard Toggle word wrap
The two methods must implement a biunique correspondence.
For example, for any object A the following must be true: 
A.equals( transformer.fromString( transformer.toString( A ) )
Copy to Clipboard Toggle word wrap
This assumes that the transformer is the appropriate Transformer implementation for objects of type A.

Important

The Query Module is currently only available as a Technical Preview for JBoss Data Grid 6.1.
Report a bug
Back to top
Red Hat logoGithubredditYoutubeTwitter

Learn

Try, buy, & sell

Communities

About Red Hat Documentation

We help Red Hat users innovate and achieve their goals with our products and services with content they can trust. Explore our recent updates.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. For more details, see the Red Hat Blog.

About Red Hat

We deliver hardened solutions that make it easier for enterprises to work across platforms and environments, from the core datacenter to the network edge.

Theme

© 2025 Red Hat