org.dspace.services.model.RequestInterceptor Maven / Gradle / Ivy
/**
* The contents of this file are subject to the license and copyright
* detailed in the LICENSE and NOTICE files at the root of the source
* tree and available online at
*
* http://www.dspace.org/license/
*/
package org.dspace.services.model;
import org.dspace.kernel.mixins.OrderedService;
/**
* Executes at the beginning and/or end of system requests.
*
* Note that the ordering of these must be set specifically higher than
* 0 or an exception will occur. If you do not really care what the
* order is you are encouraged to use 10.
*
* Note that the highest priority interceptor will be executed first in
* request start and last on request end. The lowest priority
* interceptor would be executed last on request start and first on
* request end. If you need an interceptor which can execute first on
* request start and first on request end (or vice versa) then create 2
* interceptors. :-)
*
* @author Aaron Zeckoski (azeckoski @ gmail.com)
*/
public interface RequestInterceptor extends OrderedService {
/**
* Take actions before the request is handled for an operation.
* This will be called just before each request is sent to the
* correct request handler. For example: starting a transaction
* would happen at this point.
*
* If you want to interrupt the handling of this request (stop it)
* then throw a {@link RequestInterruptionException}.
*
* @param requestId the unique id of the request
* @param session the session associated with this request
* @throws RequestInterruptionException if this interceptor wants to stop the request
*/
public void onStart(String requestId, Session session);
/**
* Take actions after the request is handled for an operation.
* This will be called just before each operation is totally
* completed. For example: closing a transaction would happen at
* this point.
*
* If you want to interrupt the handling of this request (stop it)
* then throw a {@link RequestInterruptionException}.
*
* NOTE: it is important to realize that this will be called
* even if the request fails. Please check the incoming success
* param to see if this request was successful or not. This is your
* cue to rollback or commit, for example.
*
* @param requestId the unique id of the request
* @param session the session associated with this request
* @param succeeded true if the request operations were successful, false if there was a failure
* @param failure this is the exception associated with the failure, it is null if there is no associated exception
*/
public void onEnd(String requestId, Session session, boolean succeeded, Exception failure);
/**
* Indicate that request processing should be halted. This should
* only be used in extreme cases as it will halt all request
* processing and cause any remaining interceptors to be skipped.
* A message about the halt should be placed into the message field.
*/
public static class RequestInterruptionException extends RuntimeException {
private static final long serialVersionUID = 1L;
public RequestInterruptionException(String message, Throwable cause) {
super(message, cause);
}
public RequestInterruptionException(String message) {
super(message);
}
}
}