There are two methods available for creating a Java-based transformer in SwitchYard:

1. Implement the org.switchyard.transform.Transfomer interface and add a <transform.java> definition to your switchyard.xml.

2. Annotate one or more methods on your Java class with @Transformer.

When using the @Transformer annotation, the SwitchYard maven plugin will automatically generate the <transform.java> definition(s) for you and add them to the switchyard.xml packaged in your application.  The following Java class would produce the <transform.java> definition provided above:

@Named("MyTransformerBean")
public class MyTransformer {
    @Transformer(from = "{urn:switchyard-quickstart-demo:orders:1.0}submitOrder")
    public Order transform(Element from) {
       // handle transformation here
    }
}

The optional from and to elements of the @Transformer annotation can be used to specify the qualified type name used during transformer registration.  If not supplied, the full class name of the method parameter will be used as the from type and the full class name of the return type will be used as the to type.

The CDI bean name specified by @Named annotation is used to resolve transformer class. If you don't specify, then class name of the transformer is used instead like following:

<transforms>
   <transform.java class="org.switchyard.quickstarts.demos.orders.MyTransformer"
                   from="{urn:switchyard-quickstart-demo:orders:1.0}submitOrder"
                   to="java:org.switchyard.quickstarts.demos.orders.Order"/>
</transforms>

Note that both of above <transform.java> definition has a bean attribute or a class attribute. bean attribute and class attribute are mutually exclusive.