| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. 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. For additional information regarding |
| * copyright in this work, please see the NOTICE file in the top level |
| * directory of this distribution. |
| */ |
| |
| package org.apache.roller.weblogger.util.cache; |
| |
| import java.io.Serializable; |
| |
| |
| /** |
| * A cache entry that expires. |
| * |
| * We use this class to wrap objects being cached and associate a timestamp |
| * and timeout period with them so we can know when they expire. |
| */ |
| public class ExpiringCacheEntry implements Serializable { |
| |
| private Object value; |
| private long timeCached = -1; |
| private long timeout = 0; |
| |
| |
| public ExpiringCacheEntry(Object value, long timeout) { |
| this.value = value; |
| |
| // make sure that we don't support negative values |
| if(timeout > 0) { |
| this.timeout = timeout; |
| } |
| |
| this.timeCached = System.currentTimeMillis(); |
| } |
| |
| |
| public long getTimeCached() { |
| return this.timeCached; |
| } |
| |
| |
| public long getTimeout() { |
| return this.timeout; |
| } |
| |
| |
| /** |
| * Retrieve the value of this cache entry. |
| * |
| * If the value has expired then we return null. |
| */ |
| public Object getValue() { |
| if(this.hasExpired()) { |
| return null; |
| } else { |
| return this.value; |
| } |
| } |
| |
| |
| /** |
| * Determine if this cache entry has expired. |
| */ |
| public boolean hasExpired() { |
| |
| long now = System.currentTimeMillis(); |
| |
| return ((this.timeCached + this.timeout) < now); |
| } |
| |
| } |