Showing the changes to java/pkg/com/sun/jmx/mbeanserver/DescriptorCache.java (1 of 18352 files). Show all
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| 1 | /* | ||
| 2 | * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved. | ||
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | ||
| 4 | * | ||
| 5 | * This code is free software; you can redistribute it and/or modify it | ||
| 6 | * under the terms of the GNU General Public License version 2 only, as | ||
| 7 | * published by the Free Software Foundation. Oracle designates this | ||
| 8 | * particular file as subject to the "Classpath" exception as provided | ||
| 9 | * by Oracle in the LICENSE file that accompanied this code. | ||
| 10 | * | ||
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT | ||
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | ||
| 14 | * version 2 for more details (a copy is included in the LICENSE file that | ||
| 15 | * accompanied this code). | ||
| 16 | * | ||
| 17 | * You should have received a copy of the GNU General Public License version | ||
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, | ||
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | ||
| 20 | * | ||
| 21 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | ||
| 22 | * or visit www.oracle.com if you need additional information or have any | ||
| 23 | * questions. | ||
| 24 | */ | ||
| 25 | |||
| 26 | package com.sun.jmx.mbeanserver; | ||
| 27 | |||
| 28 | import java.lang.ref.WeakReference; | ||
| 29 | import java.util.WeakHashMap; | ||
| 30 | import javax.management.Descriptor; | ||
| 31 | import javax.management.ImmutableDescriptor; | ||
| 32 | import javax.management.JMX; | ||
| 33 | |||
| 34 | public class DescriptorCache { | ||
| 35 | private DescriptorCache() { | ||
| 36 | } | ||
| 37 | |||
| 38 | static DescriptorCache getInstance() { | ||
| 39 | return instance; | ||
| 40 | } | ||
| 41 | |||
| 42 | public static DescriptorCache getInstance(JMX proof) { | ||
| 43 | if (proof != null) | ||
| 44 | return instance; | ||
| 45 | else | ||
| 46 | return null; | ||
| 47 | } | ||
| 48 | |||
| 49 | public ImmutableDescriptor get(ImmutableDescriptor descriptor) { | ||
| 50 | WeakReference<ImmutableDescriptor> wr = map.get(descriptor); | ||
| 51 | ImmutableDescriptor got = (wr == null) ? null : wr.get(); | ||
| 52 | if (got != null) | ||
| 53 | return got; | ||
| 54 | map.put(descriptor, new WeakReference<ImmutableDescriptor>(descriptor)); | ||
| 55 | return descriptor; | ||
| 56 | } | ||
| 57 | |||
| 58 | public ImmutableDescriptor union(Descriptor... descriptors) { | ||
| 59 | return get(ImmutableDescriptor.union(descriptors)); | ||
| 60 | } | ||
| 61 | |||
| 62 | private final static DescriptorCache instance = new DescriptorCache(); | ||
| 63 | private final WeakHashMap<ImmutableDescriptor, | ||
| 64 | WeakReference<ImmutableDescriptor>> | ||
| 65 | map = new WeakHashMap<ImmutableDescriptor, | ||
| 66 | WeakReference<ImmutableDescriptor>>(); | ||
| 67 | } | ||