* A context consists of name-to-object bindings.
* The Binding class represents such a binding. It consists
* of a name and an object. The Context.listBindings()
* method returns an enumeration of Binding.
*
* Use subclassing for naming systems that generate contents of * a binding dynamically. *
* A Binding instance is not synchronized against concurrent access by multiple * threads. Threads that need to access a Binding concurrently should * synchronize amongst themselves and provide the necessary locking. * * @author Rosanna Lee * @author Scott Seligman * @since 1.3 */ public class Binding extends NameClassPair { /** * Contains this binding's object. * It is initialized by the constuctor and can be updated using * setObject. * @serial * @see #getObject * @see #setObject */ private Object boundObj; /** * Constructs an instance of a Binding given its name and object. *
* getClassName() will return
* the class name of obj (or null if obj is null)
* unless the class name has been explicitly set using setClassName()
*
* @param name The non-null name of the object. It is relative
* to the target context (which is
* named by the first parameter of the listBindings() method)
* @param obj The possibly null object bound to name.
* @see NameClassPair#setClassName
*/
public Binding(String name, Object obj) {
super(name, null);
this.boundObj = obj;
}
/**
* Constructs an instance of a Binding given its name, object, and whether
* the name is relative.
*
* getClassName() will return the class name of obj
* (or null if obj is null) unless the class name has been
* explicitly set using setClassName()
*
* @param name The non-null string name of the object.
* @param obj The possibly null object bound to name.
* @param isRelative true if name is a name relative
* to the target context (which is named by
* the first parameter of the listBindings() method);
* false if name is a URL string.
* @see NameClassPair#isRelative
* @see NameClassPair#setRelative
* @see NameClassPair#setClassName
*/
public Binding(String name, Object obj, boolean isRelative) {
super(name, null, isRelative);
this.boundObj = obj;
}
/**
* Constructs an instance of a Binding given its name, class name, and object.
*
* @param name The non-null name of the object. It is relative
* to the target context (which is
* named by the first parameter of the listBindings() method)
* @param className The possibly null class name of the object
* bound to name. If null, the class name of obj is
* returned by getClassName(). If obj is also
* null, getClassName() will return null.
* @param obj The possibly null object bound to name.
* @see NameClassPair#setClassName
*/
public Binding(String name, String className, Object obj) {
super(name, className);
this.boundObj = obj;
}
/**
* Constructs an instance of a Binding given its
* name, class name, object, and whether the name is relative.
*
* @param name The non-null string name of the object.
* @param className The possibly null class name of the object
* bound to name. If null, the class name of obj is
* returned by getClassName(). If obj is also
* null, getClassName() will return null.
* @param obj The possibly null object bound to name.
* @param isRelative true if name is a name relative
* to the target context (which is named by
* the first parameter of the listBindings() method);
* false if name is a URL string.
* @see NameClassPair#isRelative
* @see NameClassPair#setRelative
* @see NameClassPair#setClassName
*/
public Binding(String name, String className, Object obj, boolean isRelative) {
super(name, className, isRelative);
this.boundObj = obj;
}
/**
* Retrieves the class name of the object bound to the name of this binding.
* If the class name has been set explicitly, return it.
* Otherwise, if this binding contains a non-null object,
* that object's class name is used. Otherwise, null is returned.
*
* @return A possibly null string containing class name of object bound.
*/
public String getClassName() {
String cname = super.getClassName();
if (cname != null) {
return cname;
}
if (boundObj != null)
return boundObj.getClass().getName();
else
return null;
}
/**
* Retrieves the object bound to the name of this binding.
*
* @return The object bound; null if this binding does not contain an object.
* @see #setObject
*/
public Object getObject() {
return boundObj;
}
/**
* Sets the object associated with this binding.
* @param obj The possibly null object to use.
* @see #getObject
*/
public void setObject(Object obj) {
boundObj = obj;
}
/**
* Generates the string representation of this binding.
* The string representation consists of the string representation
* of the name/class pair and the string representation of
* this binding's object, separated by ':'.
* The contents of this string is useful
* for debugging and is not meant to be interpreted programmatically.
*
* @return The non-null string representation of this binding.
*/
public String toString() {
return super.toString() + ":" + getObject();
}
/**
* Use serialVersionUID from JNDI 1.1.1 for interoperability
*/
private static final long serialVersionUID = 8839217842691845890L;
};