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
018package org.apache.log4j.helpers;
019
020import java.util.Date;
021import java.text.FieldPosition;
022import java.text.ParsePosition;
023import java.text.DateFormat;
024
025/**
026   Formats a {@link Date} by printing the number of milliseconds
027   elapsed since construction of the format.  This is the fastest
028   printing DateFormat in the package.
029   
030   @author Ceki Gülcü
031   
032   @since 0.7.5
033*/
034public class RelativeTimeDateFormat extends DateFormat {
035  private static final long serialVersionUID = 7055751607085611984L;
036
037
038  protected final long startTime;
039
040  public
041  RelativeTimeDateFormat() {
042    this.startTime = System.currentTimeMillis();
043  }
044  
045  /**
046     Appends to <code>sbuf</code> the number of milliseconds elapsed
047     since the start of the application. 
048     
049     @since 0.7.5
050  */
051  public
052  StringBuffer format(Date date, StringBuffer sbuf,
053                      FieldPosition fieldPosition) {
054    //System.err.println(":"+ date.getTime() + " - " + startTime);
055    return sbuf.append((date.getTime() - startTime));
056  }
057
058  /**
059     This method does not do anything but return <code>null</code>.
060   */
061  public
062  Date parse(java.lang.String s, ParsePosition pos) {
063    return null;
064  }  
065}