Chapter 56. The Interceptor APIs

All of the interceptors in Apache CXF implement the base Interceptor interface shown in Example 56.1, “Base interceptor interface”.

package org.apache.cxf.interceptor;

public interface Interceptor<T extends Message>
{

  void handleMessage(T message) throws Fault;

  void handleFault(T message);

}

package org.apache.cxf.interceptor;

public interface Interceptor<T extends Message>
{

  void handleMessage(T message) throws Fault;

  void handleFault(T message);

}

The Interceptor interface defines the two methods that a developer needs to implement for a custom interceptor:

Most interceptors do not directly implement the Interceptor interface. Instead, they implement the PhaseInterceptor interface shown in Example 56.2, “The phase interceptor interface”. The PhaseInterceptor interface adds four methods that allow an interceptor the participate in interceptor chains.

package org.apache.cxf.phase;
...

public interface PhaseInterceptor<T extends Message> extends Interceptor<T>
{

    Set<String> getAfter();

    Set<String> getBefore();

    String getId();

    String getPhase();

}

package org.apache.cxf.phase;
...

public interface PhaseInterceptor<T extends Message> extends Interceptor<T>
{

    Set<String> getAfter();

    Set<String> getBefore();

    String getId();

    String getPhase();

}

Instead of directly implementing the PhaseInterceptor interface, developers should extend the AbstractPhaseInterceptor class. This abstract class provides implementations for the phase management methods of the PhaseInterceptor interface. The AbstractPhaseInterceptor class also provides a default implementation of the handleFault() method.

Developers need to provide an implementation of the handleMessage() method. They can also provide a different implementation for the handleFault() method. The developer-provided implementations can manipulate the message data using the methods provided by the generic org.apache.cxf.message.Message interface.

For applications that work with SOAP messages, Apache CXF provides an AbstractSoapInterceptor class. Extending this class provides the handleMessage() method and the handleFault() method with access to the message data as an org.apache.cxf.binding.soap.SoapMessage object. SoapMessage objects have methods for retrieving the SOAP headers, the SOAP envelope, and other SOAP metadata from the message.