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| 1 | /* | ||
| 2 | * Copyright (c) 2005, 2006, 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.tools.attach; | ||
| 27 | |||
| 28 | import com.sun.tools.attach.spi.AttachProvider; | ||
| 29 | |||
| 30 | /** | ||
| 31 | * Describes a Java virtual machine. | ||
| 32 | * | ||
| 33 | * <p> A <code>VirtualMachineDescriptor</code> is a container class used to | ||
| 34 | * describe a Java virtual machine. It encapsulates an identifier that identifies | ||
| 35 | * a target virtual machine, and a reference to the {@link | ||
| 36 | * com.sun.tools.attach.spi.AttachProvider AttachProvider} that should be used | ||
| 37 | * when attempting to attach to the virtual machine. The identifier is | ||
| 38 | * implementation-dependent but is typically the process identifier (or pid) | ||
| 39 | * environments where each Java virtual machine runs in its own operating system | ||
| 40 | * process. </p> | ||
| 41 | * | ||
| 42 | * <p> A <code>VirtualMachineDescriptor</code> also has a {@link #displayName() displayName}. | ||
| 43 | * The display name is typically a human readable string that a tool might | ||
| 44 | * display to a user. For example, a tool that shows a list of Java | ||
| 45 | * virtual machines running on a system might use the display name rather | ||
| 46 | * than the identifier. A <code>VirtualMachineDescriptor</code> may be | ||
| 47 | * created without a <i>display name</i>. In that case the identifier is | ||
| 48 | * used as the <i>display name</i>. | ||
| 49 | * | ||
| 50 | * <p> <code>VirtualMachineDescriptor</code> instances are typically created by | ||
| 51 | * invoking the {@link com.sun.tools.attach.VirtualMachine#list VirtualMachine.list()} | ||
| 52 | * method. This returns the complete list of descriptors to describe the | ||
| 53 | * Java virtual machines known to all installed {@link | ||
| 54 | * com.sun.tools.attach.spi.AttachProvider attach providers}. | ||
| 55 | * | ||
| 56 | * @since 1.6 | ||
| 57 | */ | ||
| 58 | public class VirtualMachineDescriptor { | ||
| 59 | |||
| 60 | private AttachProvider provider; | ||
| 61 | private String id; | ||
| 62 | private String displayName; | ||
| 63 | |||
| 64 | private volatile int hash; // 0 => not computed | ||
| 65 | |||
| 66 | /** | ||
| 67 | * Creates a virtual machine descriptor from the given components. | ||
| 68 | * | ||
| 69 | * @param provider The AttachProvider to attach to the Java virtual machine. | ||
| 70 | * @param id The virtual machine identifier. | ||
| 71 | * @param displayName The display name. | ||
| 72 | * | ||
| 73 | * @throws NullPointerException | ||
| 74 | * If any of the arguments are <code>null</code> | ||
| 75 | */ | ||
| 76 | public VirtualMachineDescriptor(AttachProvider provider, String id, String displayName) { | ||
| 77 | if (provider == null) { | ||
| 78 | throw new NullPointerException("provider cannot be null"); | ||
| 79 | } | ||
| 80 | if (id == null) { | ||
| 81 | throw new NullPointerException("identifier cannot be null"); | ||
| 82 | } | ||
| 83 | if (displayName == null) { | ||
| 84 | throw new NullPointerException("display name cannot be null"); | ||
| 85 | } | ||
| 86 | this.provider = provider; | ||
| 87 | this.id = id; | ||
| 88 | this.displayName = displayName; | ||
| 89 | } | ||
| 90 | |||
| 91 | /** | ||
| 92 | * Creates a virtual machine descriptor from the given components. | ||
| 93 | * | ||
| 94 | * <p> This convenience constructor works as if by invoking the | ||
| 95 | * three-argument constructor as follows: | ||
| 96 | * | ||
| 97 | * <blockquote><tt> | ||
| 98 | * new {@link #VirtualMachineDescriptor(AttachProvider, String, String) | ||
| 99 | * VirtualMachineDescriptor}(provider, id, id); | ||
| 100 | * </tt></blockquote> | ||
| 101 | * | ||
| 102 | * <p> That is, it creates a virtual machine descriptor such that | ||
| 103 | * the <i>display name</i> is the same as the virtual machine | ||
| 104 | * identifier. | ||
| 105 | * | ||
| 106 | * @param provider The AttachProvider to attach to the Java virtual machine. | ||
| 107 | * @param id The virtual machine identifier. | ||
| 108 | * | ||
| 109 | * @throws NullPointerException | ||
| 110 | * If <tt>provider</tt> or <tt>id</tt> is <tt>null</tt>. | ||
| 111 | */ | ||
| 112 | public VirtualMachineDescriptor(AttachProvider provider, String id) { | ||
| 113 | this(provider, id, id); | ||
| 114 | } | ||
| 115 | |||
| 116 | /** | ||
| 117 | * Return the <code>AttachProvider</code> that this descriptor references. | ||
| 118 | * | ||
| 119 | * @return The <code>AttachProvider</code> that this descriptor references. | ||
| 120 | */ | ||
| 121 | public AttachProvider provider() { | ||
| 122 | return provider; | ||
| 123 | } | ||
| 124 | |||
| 125 | /** | ||
| 126 | * Return the identifier component of this descriptor. | ||
| 127 | * | ||
| 128 | * @return The identifier component of this descriptor. | ||
| 129 | */ | ||
| 130 | public String id() { | ||
| 131 | return id; | ||
| 132 | } | ||
| 133 | |||
| 134 | /** | ||
| 135 | * Return the <i>display name</i> component of this descriptor. | ||
| 136 | * | ||
| 137 | * @return The display name component of this descriptor. | ||
| 138 | */ | ||
| 139 | public String displayName() { | ||
| 140 | return displayName; | ||
| 141 | } | ||
| 142 | |||
| 143 | /** | ||
| 144 | * Returns a hash-code value for this VirtualMachineDescriptor. The hash | ||
| 145 | * code is based upon the descriptor's components, and satifies | ||
| 146 | * the general contract of the {@link java.lang.Object#hashCode() | ||
| 147 | * Object.hashCode} method. | ||
| 148 | * | ||
| 149 | * @return A hash-code value for this descriptor. | ||
| 150 | */ | ||
| 151 | public int hashCode() { | ||
| 152 | if (hash != 0) { | ||
| 153 | return hash; | ||
| 154 | } | ||
| 155 | hash = provider.hashCode() * 127 + id.hashCode(); | ||
| 156 | return hash; | ||
| 157 | } | ||
| 158 | |||
| 159 | /** | ||
| 160 | * Tests this VirtualMachineDescriptor for equality with another object. | ||
| 161 | * | ||
| 162 | * <p> If the given object is not a VirtualMachineDescriptor then this | ||
| 163 | * method returns <tt>false</tt>. For two VirtualMachineDescriptors to | ||
| 164 | * be considered equal requires that they both reference the same | ||
| 165 | * provider, and their {@link #id() identifiers} are equal. </p> | ||
| 166 | * | ||
| 167 | * <p> This method satisfies the general contract of the {@link | ||
| 168 | * java.lang.Object#equals(Object) Object.equals} method. </p> | ||
| 169 | * | ||
| 170 | * @param ob The object to which this object is to be compared | ||
| 171 | * | ||
| 172 | * @return <tt>true</tt> if, and only if, the given object is | ||
| 173 | * a VirtualMachineDescriptor that is equal to this | ||
| 174 | * VirtualMachineDescriptor. | ||
| 175 | */ | ||
| 176 | public boolean equals(Object ob) { | ||
| 177 | if (ob == this) | ||
| 178 | return true; | ||
| 179 | if (!(ob instanceof VirtualMachineDescriptor)) | ||
| 180 | return false; | ||
| 181 | VirtualMachineDescriptor other = (VirtualMachineDescriptor)ob; | ||
| 182 | if (other.provider() != this.provider()) { | ||
| 183 | return false; | ||
| 184 | } | ||
| 185 | if (!other.id().equals(this.id())) { | ||
| 186 | return false; | ||
| 187 | } | ||
| 188 | return true; | ||
| 189 | } | ||
| 190 | |||
| 191 | /** | ||
| 192 | * Returns the string representation of the <code>VirtualMachineDescriptor</code>. | ||
| 193 | */ | ||
| 194 | public String toString() { | ||
| 195 | String s = provider.toString() + ": " + id; | ||
| 196 | if (displayName != id) { | ||
| 197 | s += " " + displayName; | ||
| 198 | } | ||
| 199 | return s; | ||
| 200 | } | ||
| 201 | |||
| 202 | |||
| 203 | } | ||