org.apache.xmlgraphics.image.loader.cache.DefaultExpirationPolicy Maven / Gradle / Ivy
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* 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.
*/
/* $Id: DefaultExpirationPolicy.java 1681108 2015-05-22 13:26:12Z ssteiner $ */
package org.apache.xmlgraphics.image.loader.cache;
/**
* Implements the default expiration policy for the image cache.
*/
public class DefaultExpirationPolicy implements ExpirationPolicy {
public static final int EXPIRATION_IMMEDIATE = 0;
public static final int EXPIRATION_NEVER = -1;
private int expirationAfter; //in seconds
/**
* Creates a new policy with default settings (expiration in 60 seconds).
*/
public DefaultExpirationPolicy() {
this(60);
}
/**
* Creates a new policy.
* @param expirationAfter the expiration in seconds (a negative value means: never expire)
*/
public DefaultExpirationPolicy(int expirationAfter) {
this.expirationAfter = expirationAfter;
}
private boolean isNeverExpired() {
return (this.expirationAfter < 0);
}
/** {@inheritDoc} */
public boolean isExpired(TimeStampProvider provider, long timestamp) {
if (isNeverExpired()) {
return false;
} else {
long now = provider.getTimeStamp();
return now >= (timestamp + (this.expirationAfter * 1000L));
}
}
}