org.argeo.slc.repo/src/org/eclipse/aether/DefaultSessionData.java

   1 /*******************************************************************************
   2  * Copyright (c) 2010, 2014 Sonatype, Inc.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Eclipse Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/epl-v10.html
   7  *
   8  * Contributors:
   9  *    Sonatype, Inc. - initial API and implementation
  10  *******************************************************************************/
  11 package org.eclipse.aether;
  12
  13 import java.util.concurrent.ConcurrentHashMap;
  14 import java.util.concurrent.ConcurrentMap;
  15
  16 /**
  17  * A simple session data storage backed by a thread-safe map.
  18  */
  19 public final class DefaultSessionData
  20     implements SessionData
  21 {
  22
  23     private final ConcurrentMap<Object, Object> data;
  24
  25     public DefaultSessionData()
  26     {
  27         data = new ConcurrentHashMap<Object, Object>();
  28     }
  29
  30     public void set( Object key, Object value )
  31     {
  32         if ( key == null )
  33         {
  34             throw new IllegalArgumentException( "key must not be null" );
  35         }
  36
  37         if ( value != null )
  38         {
  39             data.put( key, value );
  40         }
  41         else
  42         {
  43             data.remove( key );
  44         }
  45     }
  46
  47     public boolean set( Object key, Object oldValue, Object newValue )
  48     {
  49         if ( key == null )
  50         {
  51             throw new IllegalArgumentException( "key must not be null" );
  52         }
  53
  54         if ( newValue != null )
  55         {
  56             if ( oldValue == null )
  57             {
  58                 return data.putIfAbsent( key, newValue ) == null;
  59             }
  60             return data.replace( key, oldValue, newValue );
  61         }
  62         else
  63         {
  64             if ( oldValue == null )
  65             {
  66                 return !data.containsKey( key );
  67             }
  68             return data.remove( key, oldValue );
  69         }
  70     }
  71
  72     public Object get( Object key )
  73     {
  74         if ( key == null )
  75         {
  76             throw new IllegalArgumentException( "key must not be null" );
  77         }
  78
  79         return data.get( key );
  80     }
  81
  82 }