org.apache.myfaces.trinidad.util.ref.ReferencePseudoReference Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of trinidad-api Show documentation
Public API for the Apache MyFaces Trinidad project
The newest version!
/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.myfaces.trinidad.util.ref;

import java.lang.ref.Reference;

/**
 * 
 * Implementation of PseudoReference delegating to a Reference
 * 
 */
public final class ReferencePseudoReference implements PseudoReference
{
  public ReferencePseudoReference(Reference reference)
  {
    if (reference == null)
      throw new IllegalArgumentException("reference is null");
    
    _reference = reference;
  }
    
  /**
   * Returns this reference object's referent.  If this reference object has
   * been cleared, either by the program or by the garbage collector, then
   * this method returns null.
   *
   * @return   The object to which this reference refers, or
   *           null if this reference object has been cleared
   */
  @Override
  public T get()
  {
    return _reference.get();
  }

  /**
   * Clears this reference object.  Invoking this method will not cause this
   * object to be enqueued.
   *
   *  This method is invoked only by Java code; when the garbage collector
   * clears references it does so directly, without invoking this method.
   */
  @Override
  public void clear()
  {
    _reference.clear();
  }
  
  /**
   * Tells whether or not this reference object has been enqueued, either by
   * the program or by the garbage collector.  If this reference object was
   * not registered with a queue when it was created, then this method will
   * always return false.
   *
   * @return   true if and only if this reference object has
   *           been enqueued
   */
  @Override
  public boolean isEnqueued()
  {
    return _reference.isEnqueued();
  }
  
  /**
   * Adds this reference object to the queue with which it is registered,
   * if any.
   *
   *  This method is invoked only by Java code; when the garbage collector
   * enqueues references it does so directly, without invoking this method.
   *
   * @return   true if this reference object was successfully
   *           enqueued; false if it was already enqueued or if
   *           it was not registered with a queue when it was created
   */
  @Override
  public boolean enqueue()
  {
    return _reference.enqueue();
  }
  
  private final Reference _reference;
}