001 /** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.camel.util; 018 019 import java.util.Date; 020 021 /** 022 * A very simple stop watch. 023 * <p/> 024 * This implementation is not thread safe and can only time one task at any given time. 025 * 026 * @version 027 */ 028 public final class StopWatch { 029 030 private long start; 031 private long stop; 032 033 /** 034 * Starts the stop watch 035 */ 036 public StopWatch() { 037 this(true); 038 } 039 040 /** 041 * Starts the stop watch from the given timestamp 042 */ 043 public StopWatch(Date startTimestamp) { 044 start = startTimestamp.getTime(); 045 } 046 047 /** 048 * Creates the stop watch 049 * 050 * @param started whether it should start immediately 051 */ 052 public StopWatch(boolean started) { 053 if (started) { 054 restart(); 055 } 056 } 057 058 /** 059 * Starts or restarts the stop watch 060 */ 061 public void restart() { 062 start = System.currentTimeMillis(); 063 stop = 0; 064 } 065 066 /** 067 * Stops the stop watch 068 * 069 * @return the time taken in millis. 070 */ 071 public long stop() { 072 stop = System.currentTimeMillis(); 073 return taken(); 074 } 075 076 /** 077 * Returns the time taken in millis. 078 * 079 * @return time in millis 080 */ 081 public long taken() { 082 if (start > 0 && stop > 0) { 083 return stop - start; 084 } else if (start > 0) { 085 return System.currentTimeMillis() - start; 086 } else { 087 return 0; 088 } 089 } 090 091 }