--- /dev/null
+//
+// ========================================================================
+// Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
+// ------------------------------------------------------------------------
+// All rights reserved. This program and the accompanying materials
+// are made available under the terms of the Eclipse Public License v1.0
+// and Apache License v2.0 which accompanies this distribution.
+//
+// The Eclipse Public License is available at
+// http://www.eclipse.org/legal/epl-v10.html
+//
+// The Apache License v2.0 is available at
+// http://www.opensource.org/licenses/apache2.0.php
+//
+// You may elect to redistribute this code under either of these licenses.
+// ========================================================================
+//
+
+package org.eclipse.jetty.util;
+
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.Locale;
+import java.util.TimeZone;
+
+/* ------------------------------------------------------------ */
+/** Date Format Cache.
+ * Computes String representations of Dates and caches
+ * the results so that subsequent requests within the same second
+ * will be fast.
+ *
+ * Only format strings that contain either "ss". Sub second formatting is
+ * not handled.
+ *
+ * The timezone of the date may be included as an ID with the "zzz"
+ * format string or as an offset with the "ZZZ" format string.
+ *
+ * If consecutive calls are frequently very different, then this
+ * may be a little slower than a normal DateFormat.
+ *
+ */
+
+public class DateCache
+{
+ public static final String DEFAULT_FORMAT="EEE MMM dd HH:mm:ss zzz yyyy";
+
+ private final String _formatString;
+ private final String _tzFormatString;
+ private final SimpleDateFormat _tzFormat;
+ private final Locale _locale ;
+
+ private volatile Tick _tick;
+
+ /* ------------------------------------------------------------ */
+ /* ------------------------------------------------------------ */
+ public static class Tick
+ {
+ final long _seconds;
+ final String _string;
+ public Tick(long seconds, String string)
+ {
+ _seconds = seconds;
+ _string = string;
+ }
+ }
+
+ /* ------------------------------------------------------------ */
+ /** Constructor.
+ * Make a DateCache that will use a default format. The default format
+ * generates the same results as Date.toString().
+ */
+ public DateCache()
+ {
+ this(DEFAULT_FORMAT);
+ }
+
+ /* ------------------------------------------------------------ */
+ /** Constructor.
+ * Make a DateCache that will use the given format
+ */
+ public DateCache(String format)
+ {
+ this(format,null,TimeZone.getDefault());
+ }
+
+ /* ------------------------------------------------------------ */
+ public DateCache(String format,Locale l)
+ {
+ this(format,l,TimeZone.getDefault());
+ }
+
+ /* ------------------------------------------------------------ */
+ public DateCache(String format,Locale l,String tz)
+ {
+ this(format,l,TimeZone.getTimeZone(tz));
+ }
+
+ /* ------------------------------------------------------------ */
+ public DateCache(String format,Locale l,TimeZone tz)
+ {
+ _formatString=format;
+ _locale = l;
+
+
+ int zIndex = _formatString.indexOf( "ZZZ" );
+ if( zIndex >= 0 )
+ {
+ String ss1 = _formatString.substring( 0, zIndex );
+ String ss2 = _formatString.substring( zIndex+3 );
+ int tzOffset = tz.getRawOffset();
+
+ StringBuilder sb = new StringBuilder(_formatString.length()+10);
+ sb.append(ss1);
+ sb.append("'");
+ if( tzOffset >= 0 )
+ sb.append( '+' );
+ else
+ {
+ tzOffset = -tzOffset;
+ sb.append( '-' );
+ }
+
+ int raw = tzOffset / (1000*60); // Convert to seconds
+ int hr = raw / 60;
+ int min = raw % 60;
+
+ if( hr < 10 )
+ sb.append( '0' );
+ sb.append( hr );
+ if( min < 10 )
+ sb.append( '0' );
+ sb.append( min );
+ sb.append( '\'' );
+
+ sb.append(ss2);
+ _tzFormatString=sb.toString();
+ }
+ else
+ _tzFormatString=_formatString;
+
+ if( _locale != null )
+ {
+ _tzFormat=new SimpleDateFormat(_tzFormatString,_locale);
+ }
+ else
+ {
+ _tzFormat=new SimpleDateFormat(_tzFormatString);
+ }
+ _tzFormat.setTimeZone(tz);
+
+ _tick=null;
+ }
+
+
+ /* ------------------------------------------------------------ */
+ public TimeZone getTimeZone()
+ {
+ return _tzFormat.getTimeZone();
+ }
+
+
+ /* ------------------------------------------------------------ */
+ /** Format a date according to our stored formatter.
+ * @param inDate
+ * @return Formatted date
+ */
+ public String format(Date inDate)
+ {
+ long seconds = inDate.getTime() / 1000;
+
+ Tick tick=_tick;
+
+ // Is this the cached time
+ if (tick==null || seconds!=tick._seconds)
+ {
+ // It's a cache miss
+ synchronized (this)
+ {
+ return _tzFormat.format(inDate);
+ }
+ }
+
+ return tick._string;
+ }
+
+ /* ------------------------------------------------------------ */
+ /** Format a date according to our stored formatter.
+ * If it happens to be in the same second as the last formatNow
+ * call, then the format is reused.
+ * @param inDate
+ * @return Formatted date
+ */
+ public String format(long inDate)
+ {
+ long seconds = inDate / 1000;
+
+ Tick tick=_tick;
+
+ // Is this the cached time
+ if (tick==null || seconds!=tick._seconds)
+ {
+ // It's a cache miss
+ Date d = new Date(inDate);
+ synchronized (this)
+ {
+ return _tzFormat.format(d);
+ }
+ }
+
+ return tick._string;
+ }
+
+ /* ------------------------------------------------------------ */
+ /** Format a date according to our stored formatter.
+ * The passed time is expected to be close to the current time, so it is
+ * compared to the last value passed and if it is within the same second,
+ * the format is reused. Otherwise a new cached format is created.
+ * @param now
+ * @return Formatted date
+ */
+ public String formatNow(long now)
+ {
+ long seconds = now / 1000;
+
+ Tick tick=_tick;
+
+ // Is this the cached time
+ if (tick!=null && tick._seconds==seconds)
+ return tick._string;
+ return formatTick(now)._string;
+ }
+
+ /* ------------------------------------------------------------ */
+ public String now()
+ {
+ return formatNow(System.currentTimeMillis());
+ }
+
+ /* ------------------------------------------------------------ */
+ public Tick tick()
+ {
+ return formatTick(System.currentTimeMillis());
+ }
+
+ /* ------------------------------------------------------------ */
+ protected Tick formatTick(long now)
+ {
+ long seconds = now / 1000;
+
+ // Synchronize to protect _tzFormat
+ synchronized (this)
+ {
+ // recheck the tick, to save multiple formats
+ if (_tick==null || _tick._seconds!=seconds)
+ {
+ String s= _tzFormat.format(new Date(now));
+ return _tick=new Tick(seconds,s);
+ }
+ return _tick;
+ }
+ }
+
+ /* ------------------------------------------------------------ */
+ public String getFormatString()
+ {
+ return _formatString;
+ }
+}
projects / gigi.git / blobdiff