/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.ambari.server.events.jpa;
import javax.persistence.EntityManagerFactory;
import org.apache.ambari.server.events.AmbariEvent;
/**
* The {@link JPAEvent} class is the base for all JPA events in Ambari. Although
* this class could inherit from {@link AmbariEvent}, the publishers for
* {@link AmbariEvent} instances use an asynchronous model. With JPA, we want a
* synchronous publication model in order to ensure that events are handled
* within the scope of the method invoking them.
*/
public abstract class JPAEvent {
/**
* The {@link JPAEventType} defines the type of JPA event.
*/
public enum JPAEventType {
/**
* An event which instructs an {@link EntityManagerFactory} to evict
* instances of a particular class.
*/
CACHE_INVALIDATION;
}
/**
* The concrete event's type.
*/
protected final JPAEventType m_eventType;
/**
* Constructor.
*
* @param eventType
* the type of event (not {@code null}).
*/
public JPAEvent(JPAEventType eventType) {
m_eventType = eventType;
}
/**
* Gets the type of {@link JPAEvent}.
*
* @return the event type (never {@code null}).
*/
public JPAEventType getType() {
return m_eventType;
}
/**
* {@inheritDoc}
*/
@Override
public String toString() {
StringBuilder buffer = new StringBuilder(getClass().getSimpleName());
buffer.append("{eventType=").append(m_eventType);
buffer.append("}");
return buffer.toString();
}
}