org.snmp4j.agent.UpdatableMOSupport Maven / Gradle / Ivy
/*_############################################################################
_##
_## SNMP4J-Agent - UpdatableMOSupport.java
_##
_## Copyright (C) 2005-2009 Frank Fock (SNMP4J.org)
_##
_## Licensed 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.snmp4j.agent;
import java.util.*;
import java.lang.ref.WeakReference;
/**
* The UpdatableMOSupport class provides support for update
* {@link UpdatableManagedObject}s.
*
* @author Frank Fock
* @version 1.2
* @since 1.2
*/
public class UpdatableMOSupport {
private Date lastUpdate;
private WeakReference lastUpdateSource;
/**
* Creates a UpdatableMOSupport with undefined
* (null) last update time and source.
*/
public UpdatableMOSupport() {
}
/**
* Gets the date and time of the last update.
*
* @return the Date when the last
* {@link UpdatableManagedObject#update(MOQuery updateScope)} has been called.
*/
public Date getLastUpdate() {
return lastUpdate;
}
/**
* Sets the last update date and time.
* @param lastUpdate
* the date and time of the last successful update or null
* the reset/update a managed object on the next access.
*/
public void setLastUpdate(Date lastUpdate) {
this.lastUpdate = lastUpdate;
}
/**
* Set the last update to the current time.
*/
public void setLastUpdateNow() {
this.lastUpdate = new Date();
}
/**
* Gets the object that triggered the last update of this managed object.
*
* @return an object or null if the source of the last update
* is unknown/undefined.
*/
public Object getLastUpdateSource() {
return (lastUpdateSource == null) ? null : lastUpdateSource.get();
}
/**
* Sets the source object of the last update. The object is not directly
* referenced by this UpdatableMOSupport. Instead, a
* {@link WeakReference} is used, so that the object source can be garbage
* collected if it is not referenced elsewhere.
*
* @param source
* an Object that identifies an update source.
*/
public void setLastUpdateSource(Object source) {
this.lastUpdateSource = new WeakReference(source);
}
}