/* * Copyright (c) 2004, 2010, 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 sun.jvmstat.perfdata.monitor; import sun.jvmstat.monitor.*;import java.nio.ByteBuffer;import java.nio.charset.Charset; /** * Class for monitoring a PerfData String instrument. * * @author Brian Doherty * @since 1.5 */public class PerfStringMonitor extends PerfByteArrayMonitor       implements StringMonitor {     private static Charset defaultCharset = Charset.defaultCharset();     /**     * Constructor to create a StringMonitor object for the string instrument     * represented by the data in the given buffer.     *     * @param name the name of the string instrument     * @param v the variability attribute     * @param supported support level indicator     * @param bb the buffer containing the string instrument data.     */    public PerfStringMonitor(String name, Variability v, boolean supported,                             ByteBuffer bb) {        this(name, v, supported, bb, bb.limit());    }     /**     * Constructor to create a StringMonitor object for the string instrument     * represented by the data in the given buffer.     *     * @param name the name of the string instrument     * @param v the variability attribute     * @param supported support level indicator     * @param bb the buffer containing the string instrument data.     * @param maxLength the maximum length of the string data.     */    public PerfStringMonitor(String name, Variability v, boolean supported,                             ByteBuffer bb, int maxLength) {        super(name, Units.STRING, v, supported, bb, maxLength);    }     /**     * {@inheritDoc}     * The object returned contains a String with a copy of the current     * value of the StringInstrument.     *     * @return Object - a copy of the current value of the StringInstrument.     *                  The return value is guaranteed to be of type String.     */    public Object getValue() {        return stringValue();    }     /**     * Return the current value of the StringInstrument as a String.     *     * @return String - a copy of the current value of the StringInstrument.     */    public String stringValue() {        String str = "";        byte[] b = byteArrayValue();         // catch null strings        if ((b == null) || (b.length <= 1) || (b[0] == (byte)0)) {            return str;        }         int i;        for (i = 0; i < b.length && b[i] != (byte)0; i++);         return new String(b, 0, i, defaultCharset);    }}