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

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

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

When using the @Validator annotation, the SwitchYard maven plugin will automatically generate the <validate.java> definition(s) for you and add them to the switchyard.xml packaged in your application.

@Named("MyValidatorBean")
public class MyValidator {
    @Validator(name = "{urn:switchyard-quickstart-demo:orders:1.0}submitOrder")
    public ValidationResult validate(Element from) {
       // handle validation here
    }
}

The above Java class would produce the <validate.java> definition as following:

<validate.java bean="MyValidatorBean"
               name="{urn:switchyard-quickstart-demo:orders:1.0}submitOrder"/>

The optional name element of the @Validator annotation can be used to specify the qualified type name used during validator registration.  If not supplied, the full class name of the method parameter will be used as the type.

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

<validates>
   <validate.java class="org.switchyard.quickstarts.demos.orders.MyValidator"
                   name="{urn:switchyard-quickstart-demo:orders:1.0}submitOrder"/>
</transforms>

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

package org.switchyard.validate;
public interface ValidationResult {
    boolean isValid();
    String getDetail();
}