PerfStringMonitor.java revision 16638:0eb0f644345d
1184610Salfred/* 2184610Salfred * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved. 3184610Salfred * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4184610Salfred * 5184610Salfred * This code is free software; you can redistribute it and/or modify it 6184610Salfred * under the terms of the GNU General Public License version 2 only, as 7184610Salfred * published by the Free Software Foundation. Oracle designates this 8184610Salfred * particular file as subject to the "Classpath" exception as provided 9184610Salfred * by Oracle in the LICENSE file that accompanied this code. 10184610Salfred * 11184610Salfred * This code is distributed in the hope that it will be useful, but WITHOUT 12184610Salfred * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13184610Salfred * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14184610Salfred * version 2 for more details (a copy is included in the LICENSE file that 15184610Salfred * accompanied this code). 16184610Salfred * 17184610Salfred * You should have received a copy of the GNU General Public License version 18184610Salfred * 2 along with this work; if not, write to the Free Software Foundation, 19184610Salfred * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20184610Salfred * 21184610Salfred * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22184610Salfred * or visit www.oracle.com if you need additional information or have any 23184610Salfred * questions. 24184610Salfred */ 25184610Salfred 26184610Salfredpackage sun.jvmstat.perfdata.monitor; 27184610Salfred 28184610Salfredimport sun.jvmstat.monitor.*; 29184610Salfredimport java.nio.ByteBuffer; 30184610Salfredimport java.nio.charset.Charset; 31184610Salfred 32184610Salfred/** 33184610Salfred * Class for monitoring a PerfData String instrument. 34184610Salfred * 35184610Salfred * @author Brian Doherty 36184610Salfred * @since 1.5 37184610Salfred */ 38184610Salfredpublic class PerfStringMonitor extends PerfByteArrayMonitor 39184610Salfred implements StringMonitor { 40184610Salfred 41184610Salfred private static Charset defaultCharset = Charset.defaultCharset(); 42184610Salfred 43184610Salfred /** 44184610Salfred * Constructor to create a StringMonitor object for the string instrument 45184610Salfred * represented by the data in the given buffer. 46184610Salfred * 47184610Salfred * @param name the name of the string instrument 48184610Salfred * @param v the variability attribute 49184610Salfred * @param supported support level indicator 50184610Salfred * @param bb the buffer containing the string instrument data. 51184610Salfred */ 52184610Salfred public PerfStringMonitor(String name, Variability v, boolean supported, 53184610Salfred ByteBuffer bb) { 54184610Salfred this(name, v, supported, bb, bb.limit()); 55184610Salfred } 56184610Salfred 57184610Salfred /** 58184610Salfred * Constructor to create a StringMonitor object for the string instrument 59184610Salfred * represented by the data in the given buffer. 60184610Salfred * 61184610Salfred * @param name the name of the string instrument 62184610Salfred * @param v the variability attribute 63194677Sthompsa * @param supported support level indicator 64194677Sthompsa * @param bb the buffer containing the string instrument data. 65194677Sthompsa * @param maxLength the maximum length of the string data. 66194677Sthompsa */ 67194677Sthompsa public PerfStringMonitor(String name, Variability v, boolean supported, 68194677Sthompsa ByteBuffer bb, int maxLength) { 69194677Sthompsa super(name, Units.STRING, v, supported, bb, maxLength); 70194677Sthompsa } 71194677Sthompsa 72194677Sthompsa /** 73194677Sthompsa * {@inheritDoc} 74194677Sthompsa * The object returned contains a String with a copy of the current 75194677Sthompsa * value of the StringInstrument. 76194677Sthompsa * 77194677Sthompsa * @return Object - a copy of the current value of the StringInstrument. 78194677Sthompsa * The return value is guaranteed to be of type String. 79194677Sthompsa */ 80194677Sthompsa public Object getValue() { 81197570Sthompsa return stringValue(); 82197570Sthompsa } 83194677Sthompsa 84294637Sian /** 85294637Sian * Return the current value of the StringInstrument as a String. 86188942Sthompsa * 87194677Sthompsa * @return String - a copy of the current value of the StringInstrument. 88194677Sthompsa */ 89184610Salfred public String stringValue() { 90194228Sthompsa String str = ""; 91188942Sthompsa byte[] b = byteArrayValue(); 92194677Sthompsa 93188942Sthompsa // catch null strings 94184610Salfred if ((b == null) || (b.length <= 1) || (b[0] == (byte)0)) { 95188942Sthompsa return str; 96184610Salfred } 97197570Sthompsa 98197570Sthompsa int i; 99227309Sed for (i = 0; i < b.length && b[i] != (byte)0; i++); 100197570Sthompsa 101283341Sian return new String(b, 0, i, defaultCharset); 102283341Sian } 103283341Sian} 104294637Sian