001 /*
002 * $Id: ResourcesFactory.java 349025 2005-11-25 21:09:54Z niallp $
003 * $Revision: 349025 $
004 * $Date: 2005-11-25 21:09:54 +0000 (Fri, 25 Nov 2005) $
005 *
006 * ====================================================================
007 *
008 * Copyright 2003-2005 The Apache Software Foundation
009 *
010 * Licensed under the Apache License, Version 2.0 (the "License");
011 * you may not use this file except in compliance with the License.
012 * You may obtain a copy of the License at
013 *
014 * http://www.apache.org/licenses/LICENSE-2.0
015 *
016 * Unless required by applicable law or agreed to in writing, software
017 * distributed under the License is distributed on an "AS IS" BASIS,
018 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
019 * See the License for the specific language governing permissions and
020 * limitations under the License.
021 *
022 */
023
024 package org.apache.commons.resources;
025
026 import java.io.Serializable;
027
028 /**
029 * <a>A {@link org.apache.commons.resources.ResourcesFactory}
030 * is a factory pattern interface for a
031 * class that can create {@link org.apache.commons.resources.Resources}
032 * instances based on a logical
033 * name that is passed to the factory. Repeated requests to return a
034 * {@link org.apache.commons.resources.Resources} instance with the same
035 * name should return the same
036 * {@link org.apache.commons.resources.Resources} instance each time.</p>
037 *
038 * <p>Implementations of {@link org.apache.commons.resources.ResourcesFactory}
039 * <strong>MUST</strong>
040 * include a zero-arguments constructor so that instances of the factory
041 * can be dynamically created. Therefore, configuration information
042 * above and beyond the configuration String will generally be specified
043 * via JavaBeans property setters on the
044 * {@link org.apache.commons.resources.ResourcesFactory}
045 * implementation class.</p>
046 *
047 * @see org.apache.commons.resources.impl.ResourcesFactoryBase
048 * @see org.apache.commons.resources.impl.JDBCResourcesFactory
049 * @see org.apache.commons.resources.impl.PropertyResourcesFactory
050 * @see org.apache.commons.resources.impl.ResourceBundleResourcesFactory
051 * @see org.apache.commons.resources.impl.WebappResourcesFactoryBase
052 * @see org.apache.commons.resources.impl.WebappPropertyResourcesFactory
053 * @see org.apache.commons.resources.impl.WebappXMLResourcesFactory
054 * @see org.apache.commons.resources.impl.XMLResourcesFactory
055 */
056 public interface ResourcesFactory extends Serializable {
057
058
059 // ------------------------------------------------------------- Properties
060
061
062 /**
063 * <p>Return the <code>returnNull</code> property value that will be
064 * configured on {@link org.apache.commons.resources.Resources}
065 * instances created by this factory.</p>
066 * @return 'true' if null is returned for invalid key values.
067 */
068 public boolean isReturnNull();
069
070
071 /**
072 * <p>Set the <code>returnNull</code> property value that will be configured on
073 * {@link org.apache.commons.resources.Resources} instances created by this
074 * factory.</p>
075 *
076 * @param returnNull The new value to delegate
077 */
078 public void setReturnNull(boolean returnNull);
079
080
081 // --------------------------------------------------------- Public Methods
082
083
084 /**
085 * <p>Create (if necessary) and return a
086 * {@link org.apache.commons.resources.Resources} instance
087 * for the specified logical name, with a default configuration.</p>
088 *
089 * @param name Logical name of the
090 * {@link org.apache.commons.resources.Resources} instance to
091 * be returned
092 * @return The resources instance.
093 *
094 * @exception ResourcesException if a
095 * {@link org.apache.commons.resources.Resources} instance
096 * of the specified logical name cannot be returned.
097 */
098 public Resources getResources(String name);
099
100
101 /**
102 * <p>Create (if necessary) and return a
103 * {@link org.apache.commons.resources.Resources} instance
104 * for the specified logical name, with a configuration based on
105 * the specified configuration String.</p>
106 *
107 * @param name Logical name of the
108 * {@link org.apache.commons.resources.Resources} instance to be returned
109 * @param config Configuration string for this resource (meaning
110 * is dependent upon the {@link org.apache.commons.resources.ResourcesFactory}
111 * implementation being utilized), or <code>null</code> for the default
112 * configuration
113 * @return The resources.
114 *
115 * @exception ResourcesException if a
116 * {@link org.apache.commons.resources.Resources} instance
117 * of the specified logical name cannot be returned.
118 */
119 public Resources getResources(String name, String config);
120
121
122 /**
123 * <p>Release any internal references to
124 * {@link org.apache.commons.resources.Resources} instances
125 * that have been returned previously, after calling the
126 * <code>destroy()</code> method of each such instance.</p>
127 *
128 * @exception ResourcesException if an error occurs while releasing
129 */
130 public void release();
131
132
133 }