/**

  * Copyright 2005-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.kuali.rice.core.api.cache;

 import org.apache.commons.lang.StringUtils;

 import org.kuali.rice.core.api.CoreConstants;

 import org.kuali.rice.core.api.mo.AbstractDataTransferObject;

 import org.w3c.dom.Element;

 import javax.xml.bind.annotation.XmlAccessType;

 import javax.xml.bind.annotation.XmlAccessorType;

 import javax.xml.bind.annotation.XmlAnyElement;

 import javax.xml.bind.annotation.XmlElement;

 import javax.xml.bind.annotation.XmlRootElement;

 import javax.xml.bind.annotation.XmlType;

 import java.util.Collection;

 @XmlRootElement(name = CacheTarget.Constants.ROOT_ELEMENT_NAME)

 @XmlAccessorType(XmlAccessType.NONE)

 @XmlType(name = CacheTarget.Constants.TYPE_NAME, propOrder = {

         CacheTarget.Elements.CACHE,

         CacheTarget.Elements.KEY,

         CoreConstants.CommonElements.FUTURE_ELEMENTS

 })

 /**

  * A class that represents a target of a cache operation.  If the cache key

  * is not specified then the entire cache is the target.

  */

 public final class CacheTarget extends AbstractDataTransferObject {

     @XmlElement(name = Elements.CACHE, required = true)

     private final String cache;

     @XmlElement(name = Elements.KEY, required = false)

     private final String key;

     @SuppressWarnings("unused")

     @XmlAnyElement

     private final Collection<Element> _futureElements = null;

     /**

      * This constructor should never be called except during JAXB unmarshalling.

      */

     private CacheTarget() {

         this.cache = null;

         this.key = null;

     }

     private CacheTarget(String cache, String key) {

         if (StringUtils.isBlank(cache)) {

             throw new IllegalArgumentException("cache is blank or null");

         }

         this.cache = cache;

         this.key = key;

     }

     /**

      * Creates an instance targeting a entire cache.

      * @param cache the name of the cache.  cannot be a null of blank string.

      * @return an instance

      * @throws IllegalArgumentException if the cache is null or blank

      */

     public static CacheTarget entireCache(String cache) {

         return new CacheTarget(cache, null);

     }

     /**

      * Creates an instance targeting a single item in a cache.

      * @param cache The name of the cache.  cannot be a null of blank string.

      * @param key The key of the item in the cache.  cannot be a null of blank string.

      * @return an instance

      * @throws IllegalArgumentException if the cache or key is null or blank

      */

     public static CacheTarget singleEntry(String cache, String key) {

         if (StringUtils.isBlank(key)) {

             throw new IllegalArgumentException("a blank or null key does not target a single entry");

         }

         return new CacheTarget(cache, key);

     }

     /**

      * Checks if an instance contains a key.

      * @return true if a key exists

      */

     public boolean containsKey() {

         return key != null;

     }

     /**

      * The name of the cache to target.  will not return a null of blank string.

      * @return the name.

      */

     public String getCache() {

         return cache;

     }

     /**

      * The key of an item in the cache.  optional. can return null or blank string.

      * @return the key

      */

     public String getKey() {

         return key;

     }

     /**

      * Defines some internal constants used on this class.

      */

     static class Constants {

         final static String ROOT_ELEMENT_NAME = "cacheTarget";

         final static String TYPE_NAME = "CacheTargetType";

     }

     /**

      * A private class which exposes constants which define the XML element names to use

      * when this object is marshalled to XML.

      */

     static class Elements {

         final static String CACHE = "cache";

         final static String KEY = "key";

     }

 }