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 */ 017package org.apache.camel.util; 018 019import 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 */ 026public final class StopWatch { 027 028 private long start; 029 030 /** 031 * Starts the stop watch 032 */ 033 public StopWatch() { 034 this.start = System.currentTimeMillis(); 035 } 036 037 /** 038 * Starts the stop watch from the given timestamp 039 */ 040 public StopWatch(Date startTimestamp) { 041 start = startTimestamp.getTime(); 042 } 043 044 /** 045 * Starts the stop watch from the given timestamp 046 */ 047 public StopWatch(long timeMillis) { 048 start = timeMillis; 049 } 050 051 /** 052 * Creates the stop watch 053 * 054 * @param start whether it should start immediately 055 */ 056 public StopWatch(boolean start) { 057 if (start) { 058 this.start = System.currentTimeMillis(); 059 } 060 } 061 062 /** 063 * Starts or restarts the stop watch 064 */ 065 public void restart() { 066 start = System.currentTimeMillis(); 067 } 068 069 /** 070 * Returns the time taken in millis. 071 * 072 * @return time in millis, or <tt>0</tt> if not started yet. 073 */ 074 public long taken() { 075 if (start > 0) { 076 return System.currentTimeMillis() - start; 077 } else { 078 return 0; 079 } 080 } 081 082}