1 /*

     2  * Copyright (c) 2004, 2010, 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 sun.jvmstat.perfdata.monitor;

    27 

    28 import sun.jvmstat.monitor.*;

    29 import java.nio.ByteBuffer;

    30 

    31 /**

    32  * Class for monitoring a constant PerfData String instrument. The

    33  * value associated with a constant string instrument is fixed at

    34  * the string instrument's creation time. Its value and length never

    35  * change.

    36  *

    37  * @author Brian Doherty

    38  * @since 1.5

    39  */

    40 public class PerfStringConstantMonitor extends PerfStringMonitor {

    41 

    42     /**

    43      * The cached value of the string instrument.

    44      */

    45     String data;

    46 

    47     /**

    48      * Constructor to create a StringMonitor object for the constant string

    49      * instrument object represented by the data in the given buffer.

    50      *

    51      * @param name the name of the instrumentation object

    52      * @param supported support level indicator

    53      * @param bb the buffer containing the string instrument data

    54      */

    55     public PerfStringConstantMonitor(String name, boolean supported,

    56                                      ByteBuffer bb) {

    57         super(name, Variability.CONSTANT, supported, bb);

    58         this.data = super.stringValue();

    59     }

    60 

    61     /**

    62      * {@inheritDoc}

    63      */

    64     public Object getValue() {

    65         return data;        // return the cached string

    66     }

    67 

    68     /**

    69      * {@inheritDoc}

    70      */

    71     public String stringValue() {

    72         return data;        // return the cached string

    73     }

    74 }