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/* * Copyright (c) 2005, 2006, 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.management; import sun.management.VMOptionCompositeData;import javax.management.openmbean.CompositeData; /** * Information about a VM option including its value and * where the value came from which is referred as its * {@link VMOption.Origin <i>origin</i>}. * <p> * Each VM option has a default value.  A VM option can * be set at VM creation time typically as a command line * argument to the launcher or an argument passed to the * VM created using the JNI invocation interface. * In addition, a VM option may be set via an environment * variable or a configuration file. A VM option can also * be set dynamically via a management interface after * the VM was started. * * A <tt>VMOption</tt> contains the value of a VM option * and the origin of that value at the time this <tt>VMOption</tt> * object was constructed.  The value of the VM option * may be changed after the <tt>VMOption</tt> object was constructed, * * @see <a href="{@docRoot}/../../../../technotes/guides/vm/index.html"> *         Java Virtual Machine</a> * @author Mandy Chung * @since 1.6 */public class VMOption {    private String name;    private String value;    private boolean writeable;    private Origin origin;     /**     * Origin of the value of a VM option.  It tells where the     * value of a VM option came from.     *     * @since 1.6     */    public enum Origin {        /**         * The VM option has not been set and its value         * is the default value.         */        DEFAULT,        /**         * The VM option was set at VM creation time typically         * as a command line argument to the launcher or         * an argument passed to the VM created using the         * JNI invocation interface.         */        VM_CREATION,        /**         * The VM option was set via an environment variable.         */        ENVIRON_VAR,        /**         * The VM option was set via a configuration file.         */        CONFIG_FILE,        /**         * The VM option was set via the management interface after the VM         * was started.         */        MANAGEMENT,        /**         * The VM option was set via the VM ergonomic support.         */        ERGONOMIC,        /**         * The VM option was set via some other mechanism.         */        OTHER    }     /**     * Constructs a <tt>VMOption</tt>.     *     * @param name Name of a VM option.     * @param value Value of a VM option.     * @param writeable <tt>true</tt> if a VM option can be set dynamically,     *                  or <tt>false</tt> otherwise.     * @param origin where the value of a VM option came from.     *     * @throws NullPointerException if the name or value is <tt>null</tt>     */    public VMOption(String name, String value, boolean writeable, Origin origin) {        this.name = name;        this.value = value;        this.writeable = writeable;        this.origin = origin;    }     /**     * Constructs a <tt>VMOption</tt> object from a     * {@link CompositeData CompositeData}.     */    private VMOption(CompositeData cd) {        // validate the input composite data        VMOptionCompositeData.validateCompositeData(cd);         this.name = VMOptionCompositeData.getName(cd);        this.value = VMOptionCompositeData.getValue(cd);        this.writeable = VMOptionCompositeData.isWriteable(cd);        this.origin = VMOptionCompositeData.getOrigin(cd);    }     /**     * Returns the name of this VM option.     *     * @return the name of this VM option.     */    public String getName() {        return name;    }     /**     * Returns the value of this VM option at the time when     * this <tt>VMOption</tt> was created. The value could have been changed.     *     * @return the value of the VM option at the time when     *         this <tt>VMOption</tt> was created.     */    public String getValue() {        return value;    }     /**     * Returns the origin of the value of this VM option. That is,     * where the value of this VM option came from.     *     * @return where the value of this VM option came from.     */    public Origin getOrigin() {        return origin;    }     /**     * Tests if this VM option is writeable.  If this VM option is writeable,     * it can be set by the {@link HotSpotDiagnosticMXBean#setVMOption     * HotSpotDiagnosticMXBean.setVMOption} method.     *     * @return <tt>true</tt> if this VM option is writeable; <tt>false</tt>     * otherwise.     */    public boolean isWriteable() {        return writeable;    }     public String toString() {        return "VM option: " + getName() +               " value: " + value + " " +               " origin: " + origin + " " +               (writeable ? "(read-only)" : "(read-write)");    }     /**     * Returns a <tt>VMOption</tt> object represented by the     * given <tt>CompositeData</tt>. The given <tt>CompositeData</tt>     * must contain the following attributes:     * <p>     * <blockquote>     * <table border>     * <tr>     *   <th align=left>Attribute Name</th>     *   <th align=left>Type</th>     * </tr>     * <tr>     *   <td>name</td>     *   <td><tt>java.lang.String</tt></td>     * </tr>     * <tr>     *   <td>value</td>     *   <td><tt>java.lang.String</tt></td>     * </tr>     * <tr>     *   <td>origin</td>     *   <td><tt>java.lang.String</tt></td>     * </tr>     * <tr>     *   <td>writeable</td>     *   <td><tt>java.lang.Boolean</tt></td>     * </tr>     * </table>     * </blockquote>     *     * @param cd <tt>CompositeData</tt> representing a <tt>VMOption</tt>     *     * @throws IllegalArgumentException if <tt>cd</tt> does not     *   represent a <tt>VMOption</tt> with the attributes described     *   above.     *     * @return a <tt>VMOption</tt> object represented by <tt>cd</tt>     *         if <tt>cd</tt> is not <tt>null</tt>;     *         <tt>null</tt> otherwise.     */    public static VMOption from(CompositeData cd) {        if (cd == null) {            return null;        }         if (cd instanceof VMOptionCompositeData) {            return ((VMOptionCompositeData) cd).getVMOption();        } else {            return new VMOption(cd);        }     }  }