+ * 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 constructor 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;
+};