001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.xbean.naming.reference;
018
019 import java.util.Enumeration;
020 import java.util.Hashtable;
021 import java.util.NoSuchElementException;
022 import javax.naming.Context;
023 import javax.naming.Name;
024 import javax.naming.RefAddr;
025 import javax.naming.Reference;
026 import javax.naming.NamingException;
027 import javax.naming.spi.ObjectFactory;
028
029 /**
030 * @version $Rev: 355877 $ $Date: 2005-12-10 18:48:27 -0800 (Sat, 10 Dec 2005) $
031 */
032 public abstract class SimpleReference extends Reference {
033 private static final Enumeration EMPTY_ENUMERATION = new Enumeration() {
034 public boolean hasMoreElements() {
035 return false;
036 }
037
038 public Object nextElement() {
039 return new NoSuchElementException();
040 }
041 };
042
043 public SimpleReference() {
044 super(null);
045 }
046
047 /**
048 * Gets the actual referenced Object.
049 * @return the referenced object
050 */
051 public abstract Object getContent() throws NamingException;
052
053 /**
054 * We will atleast return an Object. Subclasses may want to provide a more specific class.
055 * @return "java.lang.Object"
056 */
057 public String getClassName() {
058 return "java.lang.Object";
059 }
060
061 /**
062 * If the JNDI context does not understand simple references, this method will be called
063 * to obtain the class name of a factory. This factory in turn understands the simple
064 * reference. This style is much slower because JNDI will use reflection to load and
065 * create this class.
066 * @return
067 */
068 public final String getFactoryClassName() {
069 return SimpleObjectFactory.class.getName();
070 }
071
072 //
073 // Disabled methods that we no longer need
074 //
075 public final String getFactoryClassLocation() {
076 return null;
077 }
078
079 public final RefAddr get(String addrType) {
080 return null;
081 }
082
083 public final RefAddr get(int posn) {
084 throw new ArrayIndexOutOfBoundsException(posn);
085 }
086
087 public final Enumeration getAll() {
088 return EMPTY_ENUMERATION;
089 }
090
091 public final int size() {
092 return 0;
093 }
094
095 public final void add(RefAddr addr) {
096 throw new UnsupportedOperationException("SimpleReference has no addresses so none can be added");
097 }
098
099 public final void add(int posn, RefAddr addr) {
100 throw new UnsupportedOperationException("SimpleReference has no addresses so none can be added");
101 }
102
103 public final Object remove(int posn) {
104 throw new ArrayIndexOutOfBoundsException(posn);
105 }
106
107 public final void clear() {
108 }
109
110 //
111 // Reset the java.lang.Object methods back to default implementations
112 //
113 public boolean equals(Object obj) {
114 return this == obj;
115 }
116
117 public int hashCode() {
118 return System.identityHashCode(this);
119 }
120
121 public String toString() {
122 return getClass().getName() + "@" + Integer.toHexString(hashCode());
123 }
124
125 public Object clone() {
126 throw new UnsupportedOperationException("SimpleReference can not be cloned");
127 }
128
129 /**
130 * Simply calls getContent() on the SimpleReference
131 */
132 public static final class SimpleObjectFactory implements ObjectFactory {
133 public Object getObjectInstance(Object obj, Name name, Context nameCtx, Hashtable environment) throws Exception {
134 if (obj instanceof SimpleReference) {
135 SimpleReference reference = (SimpleReference) obj;
136 return reference.getContent();
137 }
138 return null;
139 }
140 }
141 }