| /* |
| * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package com.sun.tools.attach; |
| |
| import com.sun.tools.attach.spi.AttachProvider; |
| |
| /** |
| * Describes a Java virtual machine. |
| * |
| * <p> A {@code VirtualMachineDescriptor} is a container class used to |
| * describe a Java virtual machine. It encapsulates an identifier that identifies |
| * a target virtual machine, and a reference to the {@link |
| * com.sun.tools.attach.spi.AttachProvider AttachProvider} that should be used |
| * when attempting to attach to the virtual machine. The identifier is |
| * implementation-dependent but is typically the process identifier (or pid) |
| * environments where each Java virtual machine runs in its own operating system |
| * process. </p> |
| * |
| * <p> A {@code VirtualMachineDescriptor} also has a {@link #displayName() displayName}. |
| * The display name is typically a human readable string that a tool might |
| * display to a user. For example, a tool that shows a list of Java |
| * virtual machines running on a system might use the display name rather |
| * than the identifier. A {@code VirtualMachineDescriptor} may be |
| * created without a <i>display name</i>. In that case the identifier is |
| * used as the <i>display name</i>. |
| * |
| * <p> {@code VirtualMachineDescriptor} instances are typically created by |
| * invoking the {@link com.sun.tools.attach.VirtualMachine#list VirtualMachine.list()} |
| * method. This returns the complete list of descriptors to describe the |
| * Java virtual machines known to all installed {@link |
| * com.sun.tools.attach.spi.AttachProvider attach providers}. |
| * |
| * @since 1.6 |
| */ |
| @jdk.Exported |
| public class VirtualMachineDescriptor { |
| |
| private AttachProvider provider; |
| private String id; |
| private String displayName; |
| |
| private volatile int hash; // 0 => not computed |
| |
| /** |
| * Creates a virtual machine descriptor from the given components. |
| * |
| * @param provider The AttachProvider to attach to the Java virtual machine. |
| * @param id The virtual machine identifier. |
| * @param displayName The display name. |
| * |
| * @throws NullPointerException |
| * If any of the arguments are {@code null} |
| */ |
| public VirtualMachineDescriptor(AttachProvider provider, String id, String displayName) { |
| if (provider == null) { |
| throw new NullPointerException("provider cannot be null"); |
| } |
| if (id == null) { |
| throw new NullPointerException("identifier cannot be null"); |
| } |
| if (displayName == null) { |
| throw new NullPointerException("display name cannot be null"); |
| } |
| this.provider = provider; |
| this.id = id; |
| this.displayName = displayName; |
| } |
| |
| /** |
| * Creates a virtual machine descriptor from the given components. |
| * |
| * <p> This convenience constructor works as if by invoking the |
| * three-argument constructor as follows: |
| * |
| * <blockquote><code> |
| * new {@link #VirtualMachineDescriptor(AttachProvider, String, String) |
| * VirtualMachineDescriptor}(provider, id, id); |
| * </code></blockquote> |
| * |
| * <p> That is, it creates a virtual machine descriptor such that |
| * the <i>display name</i> is the same as the virtual machine |
| * identifier. |
| * |
| * @param provider The AttachProvider to attach to the Java virtual machine. |
| * @param id The virtual machine identifier. |
| * |
| * @throws NullPointerException |
| * If {@code provider} or {@code id} is {@code null}. |
| */ |
| public VirtualMachineDescriptor(AttachProvider provider, String id) { |
| this(provider, id, id); |
| } |
| |
| /** |
| * Return the {@code AttachProvider} that this descriptor references. |
| * |
| * @return The {@code AttachProvider} that this descriptor references. |
| */ |
| public AttachProvider provider() { |
| return provider; |
| } |
| |
| /** |
| * Return the identifier component of this descriptor. |
| * |
| * @return The identifier component of this descriptor. |
| */ |
| public String id() { |
| return id; |
| } |
| |
| /** |
| * Return the <i>display name</i> component of this descriptor. |
| * |
| * @return The display name component of this descriptor. |
| */ |
| public String displayName() { |
| return displayName; |
| } |
| |
| /** |
| * Returns a hash-code value for this VirtualMachineDescriptor. The hash |
| * code is based upon the descriptor's components, and satifies |
| * the general contract of the {@link java.lang.Object#hashCode() |
| * Object.hashCode} method. |
| * |
| * @return A hash-code value for this descriptor. |
| */ |
| public int hashCode() { |
| if (hash != 0) { |
| return hash; |
| } |
| hash = provider.hashCode() * 127 + id.hashCode(); |
| return hash; |
| } |
| |
| /** |
| * Tests this VirtualMachineDescriptor for equality with another object. |
| * |
| * <p> If the given object is not a VirtualMachineDescriptor then this |
| * method returns {@code false}. For two VirtualMachineDescriptors to |
| * be considered equal requires that they both reference the same |
| * provider, and their {@link #id() identifiers} are equal. </p> |
| * |
| * <p> This method satisfies the general contract of the {@link |
| * java.lang.Object#equals(Object) Object.equals} method. </p> |
| * |
| * @param ob The object to which this object is to be compared |
| * |
| * @return {@code true} if, and only if, the given object is |
| * a VirtualMachineDescriptor that is equal to this |
| * VirtualMachineDescriptor. |
| */ |
| public boolean equals(Object ob) { |
| if (ob == this) |
| return true; |
| if (!(ob instanceof VirtualMachineDescriptor)) |
| return false; |
| VirtualMachineDescriptor other = (VirtualMachineDescriptor)ob; |
| if (other.provider() != this.provider()) { |
| return false; |
| } |
| if (!other.id().equals(this.id())) { |
| return false; |
| } |
| return true; |
| } |
| |
| /** |
| * Returns the string representation of the {@code VirtualMachineDescriptor}. |
| */ |
| public String toString() { |
| String s = provider.toString() + ": " + id; |
| if (displayName != id) { |
| s += " " + displayName; |
| } |
| return s; |
| } |
| |
| |
| } |
