1. /*

  2.  * @(#)Binding.java	1.5 00/02/02

  3.  *

  4.  * Copyright 1999, 2000 Sun Microsystems, Inc. All Rights Reserved.

  5.  * 

  6.  * This software is the proprietary information of Sun Microsystems, Inc.  

  7.  * Use is subject to license terms.

  8.  * 

  9.  */

  10. 

  11. package javax.naming;

  12. 

  13. /**

  14.   * This class represents a name-to-object binding found in a context.

  15.   *<p>

  16.   * A context consists of name-to-object bindings.

  17.   * The Binding class represents such a binding.  It consists

  18.   * of a name and an object. The <code>Context.listBindings()</code>

  19.   * method returns an enumeration of Binding.

  20.   *<p>

  21.   * Use subclassing for naming systems that generate contents of 

  22.   * a binding dynamically.

  23.   *<p>

  24.   * A Binding instance is not synchronized against concurrent access by multiple

  25.   * threads. Threads that need to access a Binding concurrently should

  26.   * synchronize amongst themselves and provide the necessary locking.

  27.   *

  28.   * @author Rosanna Lee

  29.   * @author Scott Seligman

  30.   * @version 1.5 00/02/02

  31.   * @since 1.3

  32.   */

  33. 

  34. public class Binding extends NameClassPair {

  35.     /**

  36.      * Contains this binding's object.

  37.      * It is initialized by the constuctor and can be updated using

  38.      * <tt>setObject</tt>.

  39.      * @serial

  40.      * @see #getObject

  41.      * @see #setObject

  42.      */

  43.     private Object boundObj;

  44. 

  45.     /**

  46.       * Constructs an instance of a Binding given its name and object. 

  47.       *<p>

  48.       * <tt>getClassName()</tt> will return

  49.       * the class name of <tt>obj</tt> (or null if <tt>obj</tt> is null) 

  50.       * unless the class name has been explicitly set using <tt>setClassName()</tt>

  51.       *

  52.       * @param	name	The non-null name of the object. It is relative

  53.       *             to the <em>target context</em> (which is

  54.       * named by the first parameter of the <code>listBindings()</code> method)

  55.       * @param	obj	The possibly null object bound to name.

  56.       * @see NameClassPair#setClassName

  57.       */

  58.     public Binding(String name, Object obj) {

  59. 	super(name, null);

  60. 	this.boundObj = obj;

  61.     }

  62. 

  63.     /**

  64.       * Constructs an instance of a Binding given its name, object, and whether

  65.       * the name is relative.

  66.       *<p>

  67.       * <tt>getClassName()</tt> will return the class name of <tt>obj</tt> 

  68.       * (or null if <tt>obj</tt> is null) unless the class name has been

  69.       * explicitly set using <tt>setClassName()</tt>

  70.       *

  71.       * @param	name	The non-null string name of the object.

  72.       * @param	obj	The possibly null object bound to name.

  73.       * @param isRelative true if <code>name</code> is a name relative

  74.       *		to the target context (which is named by

  75.       *         the first parameter of the <code>listBindings()</code> method);

  76.       *         false if <code>name</code> is a URL string.

  77.       * @see NameClassPair#isRelative

  78.       * @see NameClassPair#setRelative

  79.       * @see NameClassPair#setClassName

  80.       */

  81.     public Binding(String name, Object obj, boolean isRelative) {

  82. 	super(name, null, isRelative);

  83. 	this.boundObj = obj;

  84.     }

  85. 

  86.     /**

  87.       * Constructs an instance of a Binding given its name, class name, and object. 

  88.       *

  89.       * @param	name	The non-null name of the object. It is relative

  90.       *             to the <em>target context</em> (which is

  91.       * named by the first parameter of the <code>listBindings()</code> method)

  92.       * @param	className	The possibly null class name of the object 

  93.       * 	bound to <tt>name</tt>. If null, the class name of <tt>obj</tt> is

  94.       *		returned by <tt>getClassName()</tt>. If <tt>obj</tt> is also

  95.       *		null, <tt>getClassName()</tt> will return null.

  96.       * @param	obj	The possibly null object bound to name.

  97.       * @see NameClassPair#setClassName

  98.       */

  99.     public Binding(String name, String className, Object obj) {

  100. 	super(name, className);

  101. 	this.boundObj = obj;

  102.     }

  103. 

  104.     /**

  105.       * Constructs an instance of a Binding given its 

  106.       * name, class name, object, and whether the name is relative.

  107.       *

  108.       * @param	name	The non-null string name of the object.

  109.       * @param	className	The possibly null class name of the object 

  110.       * 	bound to <tt>name</tt>. If null, the class name of <tt>obj</tt> is

  111.       *		returned by <tt>getClassName()</tt>. If <tt>obj</tt> is also

  112.       *		null, <tt>getClassName()</tt> will return null.

  113.       * @param	obj	The possibly null object bound to name.

  114.       * @param isRelative true if <code>name</code> is a name relative

  115.       *		to the target context (which is named by

  116.       *         the first parameter of the <code>listBindings()</code> method);

  117.       *         false if <code>name</code> is a URL string.

  118.       * @see NameClassPair#isRelative

  119.       * @see NameClassPair#setRelative

  120.       * @see NameClassPair#setClassName

  121.       */

  122.     public Binding(String name, String className, Object obj, boolean isRelative) {

  123. 	super(name, className, isRelative);

  124. 	this.boundObj = obj;

  125.     }

  126. 

  127.     /**

  128.       * Retrieves the class name of the object bound to the name of this binding.

  129.       * If the class name has been set explicitly, return it.

  130.       * Otherwise, if this binding contains a non-null object, 

  131.       * that object's class name is used. Otherwise, null is returned.

  132.       * 

  133.       * @return	A possibly null string containing class name of object bound.

  134.       */

  135.     public String getClassName() {

  136. 	String cname = super.getClassName();

  137. 	if (cname != null) {

  138. 	    return cname;

  139. 	}

  140. 	if (boundObj != null)

  141. 	    return boundObj.getClass().getName();

  142. 	else

  143. 	    return null;

  144.     }

  145. 

  146.     /**

  147.       * Retrieves the object bound to the name of this binding.

  148.       *

  149.       * @return	The object bound; null if this binding does not contain an object.

  150.       * @see #setObject

  151.       */

  152. 

  153.     public Object getObject() {

  154. 	return boundObj;

  155.     }

  156. 

  157.     /**

  158.      * Sets the object associated with this binding.

  159.      * @param obj The possibly null object to use.

  160.      * @see #getObject

  161.      */

  162.     public void setObject(Object obj) {

  163. 	boundObj = obj;

  164.     }

  165. 

  166.     /**

  167.       * Generates the string representation of this binding.

  168.       * The string representation consists of the string representation

  169.       * of the name/class pair and the string representation of

  170.       * this binding's object, separated by ':'.

  171.       * The contents of this string is useful

  172.       * for debugging and is not meant to be interpreted programmatically.

  173.       *

  174.       * @return The non-null string representation of this binding.

  175.       */

  176. 

  177.     public String toString() {

  178. 	return super.toString() + ":" + getObject();

  179.     }

  180. 

  181.     /**

  182.      * Use serialVersionUID from JNDI 1.1.1 for interoperability

  183.      */

  184.     private static final long serialVersionUID = 8839217842691845890L;

  185. };

  186.