001 /* RefAddr.java -- Abstract superclass of addresses used in References
002 Copyright (C) 2000, 2001 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038 package javax.naming;
039
040 import java.io.Serializable;
041
042 /**
043 * Abstract superclass of addresses used in References.
044 * A <code>Reference</code> object contains a <code>Vector</code> of
045 * <code>RefAddr</code>s which are used to reference/address the object.
046 * This abstract superclass keeps track of the type of address, which will be
047 * returned by <code>getType()</code>. And defines a abstract method
048 * <code>getContent()</code> which must be implemented in concrete subclasses
049 * such as <code>BinaryRefAddr</code> and <code>StringRefAddr</code>.
050 *
051 * @see Reference
052 * @see BinaryRefAddr
053 * @see StringRefAddr
054 * @since 1.3
055 * @author Anthony Green (green@redhat.com)
056 * @author Mark Wielaard (mark@klomp.org)
057 */
058 public abstract class RefAddr implements Serializable
059 {
060 /**
061 * The string resprenstation of the type of address.
062 * Set by the constructor and returned by the getType() method.
063 */
064 protected String addrType;
065
066 /**
067 * Protected constructor for use by subclasses.
068 * Sets the addrType field of this object to the supplied String.
069 *
070 * @exception NullPointerException if the supplied String is null.
071 */
072 protected RefAddr(String addrType)
073 {
074 if (addrType == null)
075 throw new NullPointerException("addrType cannot be null");
076
077 this.addrType = addrType;
078 }
079
080 /**
081 * Returns the non-null address type given to the constructor.
082 */
083 public String getType()
084 {
085 return addrType;
086 }
087
088 /**
089 * Returns the possibly null content of this RefAddr.
090 * The actual value is defined by the non-abstract subclass.
091 */
092 public abstract Object getContent();
093
094 /**
095 * Checks if the object is a RefAddr with the same type and content.
096 *
097 * @return true if the given object is an instance of RefAddr, the addrType
098 * is the same as this addrType and the content is equals to the
099 * content of this object.
100 */
101 public boolean equals(Object o)
102 {
103 if (o instanceof RefAddr)
104 {
105 RefAddr refAddr = (RefAddr) o;
106 if (this.getType().equals(refAddr.getType()))
107 {
108 Object c1 = this.getContent();
109 Object c2 = refAddr.getContent();
110 if (c1 == null)
111 return c2 == null;
112 else
113 return c1.equals(c2);
114 }
115 }
116 return false;
117 }
118
119 /**
120 * Returns the hashCode which is the hasCode of the String returned by
121 * <code>getType()</code> plus the hashCode of the Object returned by
122 * <code>getContent</code> (when not null).
123 */
124 public int hashCode()
125 {
126 int result = getType().hashCode();
127 Object o = getContent();
128 if (o != null)
129 result += o.hashCode();
130
131 return result;
132 }
133
134 /**
135 * Returns a String representation of the RefAddr.
136 * Should only be used for debugging purposes.
137 */
138 public String toString()
139 {
140 return "[RefAddr type: " + getType() + " content: " + getContent() + ']';
141 }
142 }