beagled/Lucene.Net/Document/DateTools.cs

   1 /*
   2  * Copyright 2004 The Apache Software Foundation
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 using System;
  18
  19 namespace Lucene.Net.Documents
  20 {
  21
  22         /// <summary> Provides support for converting dates to strings and vice-versa.
  23         /// The strings are structured so that lexicographic sorting orders
  24         /// them by date, which makes them suitable for use as field values
  25         /// and search terms.
  26         ///
  27         /// <P>This class also helps you to limit the resolution of your dates. Do not
  28         /// save dates with a finer resolution than you really need, as then
  29         /// RangeQuery and PrefixQuery will require more memory and become slower.
  30         ///
  31         /// <P>Compared to {@link DateField} the strings generated by the methods
  32         /// in this class take slightly more space, unless your selected resolution
  33         /// is set to <code>Resolution.DAY</code> or lower.
  34         /// </summary>
  35         public class DateTools
  36         {
  37
  38                 private DateTools()
  39                 {
  40                 }
  41
  42                 /// <summary> Converts a Date to a string suitable for indexing.
  43                 ///
  44                 /// </summary>
  45                 /// <param name="date">the date to be converted
  46                 /// </param>
  47                 /// <param name="resolution">the desired resolution, see
  48                 /// {@link #Round(Date, DateTools.Resolution)}
  49                 /// </param>
  50                 /// <returns> a string in format <code>yyyyMMddHHmmssSSS</code> or shorter,
  51                 /// depeding on <code>resolution</code>
  52                 /// </returns>
  53                 public static System.String DateToString(System.DateTime date, Resolution resolution)
  54                 {
  55                         return TimeToString(date.Ticks, resolution);
  56                 }
  57
  58                 /// <summary> Converts a millisecond time to a string suitable for indexing.
  59                 ///
  60                 /// </summary>
  61                 /// <param name="time">the date expressed as milliseconds since January 1, 1970, 00:00:00 GMT
  62                 /// </param>
  63                 /// <param name="resolution">the desired resolution, see
  64                 /// {@link #Round(long, DateTools.Resolution)}
  65                 /// </param>
  66                 /// <returns> a string in format <code>yyyyMMddHHmmssSSS</code> or shorter,
  67                 /// depeding on <code>resolution</code>
  68                 /// </returns>
  69                 public static System.String TimeToString(long time, Resolution resolution)
  70                 {
  71                         System.Globalization.Calendar cal = new System.Globalization.GregorianCalendar(); // {{Aroush}} do we care about 'cal'
  72
  73                         //protected in JDK's prior to 1.4
  74                         //cal.setTimeInMillis(round(time, resolution));
  75
  76                         System.DateTime dt = new System.DateTime(Round(time, resolution));
  77
  78                         System.String t = "";
  79
  80             if (resolution == Resolution.YEAR)
  81             {
  82                 t = dt.ToString("yyyy");
  83             }
  84             else if (resolution == Resolution.MONTH)
  85             {
  86                 t = dt.ToString("yyyyMM");
  87             }
  88             else if (resolution == Resolution.DAY)
  89             {
  90                 t = dt.ToString("yyyyMMdd");
  91             }
  92             else if (resolution == Resolution.HOUR)
  93             {
  94                 t = dt.ToString("yyyyMMddHH");
  95             }
  96             else if (resolution == Resolution.MINUTE)
  97             {
  98                 t = dt.ToString("yyyyMMddHHmm");
  99             }
 100             else if (resolution == Resolution.SECOND)
 101             {
 102                 t = dt.ToString("yyyyMMddHHmmss");
 103             }
 104             else if (resolution == Resolution.MILLISECOND)
 105             {
 106                 t = dt.ToString("yyyyMMddHHmmssfff");
 107             }
 108             else
 109             {
 110                 throw new System.ArgumentException("unknown resolution " + resolution);
 111             }
 112
 113             return t;
 114                 }
 115
 116                 /// <summary> Converts a string produced by <code>timeToString</code> or
 117                 /// <code>DateToString</code> back to a time, represented as the
 118                 /// number of milliseconds since January 1, 1970, 00:00:00 GMT.
 119                 ///
 120                 /// </summary>
 121                 /// <param name="dateString">the date string to be converted
 122                 /// </param>
 123                 /// <returns> the number of milliseconds since January 1, 1970, 00:00:00 GMT
 124                 /// </returns>
 125                 /// <throws>  ParseException if <code>dateString</code> is not in the  </throws>
 126                 /// <summary>  expected format
 127                 /// </summary>
 128                 public static long StringToTime(System.String dateString)
 129                 {
 130                         return StringToDate(dateString).Ticks;
 131                 }
 132
 133                 /// <summary> Converts a string produced by <code>timeToString</code> or
 134                 /// <code>DateToString</code> back to a time, represented as a
 135                 /// Date object.
 136                 ///
 137                 /// </summary>
 138                 /// <param name="dateString">the date string to be converted
 139                 /// </param>
 140                 /// <returns> the parsed time as a Date object
 141                 /// </returns>
 142                 /// <throws>  ParseException if <code>dateString</code> is not in the  </throws>
 143                 /// <summary>  expected format
 144                 /// </summary>
 145                 public static System.DateTime StringToDate(System.String dateString)
 146                 {
 147             System.String yyyy = "1";
 148             System.String MM = "1";
 149             System.String dd = "1";
 150             System.String HH = "0";
 151             System.String mm = "0";
 152             System.String ss = "0";
 153             System.String SSS = "0";
 154
 155             if (dateString.Length == 4)     // "yyyy"
 156             {
 157                 yyyy = dateString.Substring(0, 4);
 158             }
 159             else if (dateString.Length == 6)     // "yyyyMM";
 160             {
 161                 yyyy = dateString.Substring(0, 4);
 162                 MM = dateString.Substring(4, 2);
 163             }
 164             else if (dateString.Length == 8)     // "yyyyMMdd"
 165             {
 166                 yyyy = dateString.Substring(0, 4);
 167                 MM = dateString.Substring(4, 2);
 168                 dd = dateString.Substring(6, 2);
 169             }
 170             else if (dateString.Length == 10)    // "yyyyMMddHH"
 171             {
 172                 yyyy = dateString.Substring(0, 4);
 173                 MM = dateString.Substring(4, 2);
 174                 dd = dateString.Substring(6, 2);
 175                 HH = dateString.Substring(8, 2);
 176             }
 177             else if (dateString.Length == 12)    // "yyyyMMddHHmm";
 178             {
 179                 yyyy = dateString.Substring(0, 4);
 180                 MM = dateString.Substring(4, 2);
 181                 dd = dateString.Substring(6, 2);
 182                 HH = dateString.Substring(8, 2);
 183                 mm = dateString.Substring(10, 2);
 184             }
 185             else if (dateString.Length == 14)    // "yyyyMMddHHmmss";
 186             {
 187                 yyyy = dateString.Substring(0, 4);
 188                 MM = dateString.Substring(4, 2);
 189                 dd = dateString.Substring(6, 2);
 190                 HH = dateString.Substring(8, 2);
 191                 mm = dateString.Substring(10, 2);
 192                 ss = dateString.Substring(12, 2);
 193             }
 194             else if (dateString.Length == 17)    // "yyyyMMddHHmmssSSS";
 195             {
 196                 yyyy = dateString.Substring(0, 4);
 197                 MM = dateString.Substring(4, 2);
 198                 dd = dateString.Substring(6, 2);
 199                 HH = dateString.Substring(8, 2);
 200                 mm = dateString.Substring(10, 2);
 201                 ss = dateString.Substring(12, 2);
 202                 SSS = dateString.Substring(14, 3);
 203             }
 204             else
 205             {
 206                 throw new System.FormatException("Input is not valid date string: " + dateString);
 207             }
 208
 209             int y, M, d, H, m, s, S;
 210             y = Convert.ToInt16(yyyy);
 211             M = Convert.ToInt16(MM);
 212             d = Convert.ToInt16(dd);
 213             H = Convert.ToInt16(HH);
 214             m = Convert.ToInt16(mm);
 215             s = Convert.ToInt16(ss);
 216             S = Convert.ToInt16(SSS);
 217
 218             return new System.DateTime(y,
 219                 M, d, H,
 220                 m, s, S);
 221
 222             //return new System.DateTime(Convert.ToInt16(yyyy),
 223             //    Convert.ToInt16(MM), Convert.ToInt16(dd), Convert.ToInt16(HH),
 224             //    Convert.ToInt16(mm), Convert.ToInt16(ss), Convert.ToInt16(SSS));
 225         }
 226
 227                 /// <summary> Limit a date's resolution. For example, the date <code>2004-09-21 13:50:11</code>
 228                 /// will be changed to <code>2004-09-01 00:00:00</code> when using
 229                 /// <code>Resolution.MONTH</code>.
 230                 ///
 231                 /// </summary>
 232                 /// <param name="resolution">The desired resolution of the date to be returned
 233                 /// </param>
 234                 /// <returns> the date with all values more precise than <code>resolution</code>
 235                 /// set to 0 or 1
 236                 /// </returns>
 237         public static System.DateTime Round(System.DateTime date, Resolution resolution)
 238         {
 239             return new System.DateTime(Round(date.Ticks, resolution));
 240         }
 241
 242                 /// <summary> Limit a date's resolution. For example, the date <code>1095767411000</code>
 243                 /// (which represents 2004-09-21 13:50:11) will be changed to
 244                 /// <code>1093989600000</code> (2004-09-01 00:00:00) when using
 245                 /// <code>Resolution.MONTH</code>.
 246                 ///
 247                 /// </summary>
 248                 /// <param name="resolution">The desired resolution of the date to be returned
 249                 /// </param>
 250                 /// <returns> the date with all values more precise than <code>resolution</code>
 251                 /// set to 0 or 1, expressed as milliseconds since January 1, 1970, 00:00:00 GMT
 252                 /// </returns>
 253         public static long Round(long time, Resolution resolution)
 254         {
 255             System.Globalization.Calendar cal = new System.Globalization.GregorianCalendar(); // {{Aroush}} do we care about 'cal'
 256
 257             // protected in JDK's prior to 1.4
 258             //cal.setTimeInMillis(time);
 259
 260             System.DateTime dt = new System.DateTime(time);
 261
 262             if (resolution == Resolution.YEAR)
 263             {
 264                 dt = dt.AddMonths(1 - dt.Month);
 265                 dt = dt.AddDays(1 - dt.Day);
 266                 dt = dt.AddHours(0 - dt.Hour);
 267                 dt = dt.AddMinutes(0 - dt.Minute);
 268                 dt = dt.AddSeconds(0 - dt.Second);
 269                 dt = dt.AddMilliseconds(0 - dt.Millisecond);
 270             }
 271             else if (resolution == Resolution.MONTH)
 272             {
 273                 dt = dt.AddDays(1 - dt.Day);
 274                 dt = dt.AddHours(0 - dt.Hour);
 275                 dt = dt.AddMinutes(0 - dt.Minute);
 276                 dt = dt.AddSeconds(0 - dt.Second);
 277                 dt = dt.AddMilliseconds(0 - dt.Millisecond);
 278             }
 279             else if (resolution == Resolution.DAY)
 280             {
 281                 dt = dt.AddHours(0 - dt.Hour);
 282                 dt = dt.AddMinutes(0 - dt.Minute);
 283                 dt = dt.AddSeconds(0 - dt.Second);
 284                 dt = dt.AddMilliseconds(0 - dt.Millisecond);
 285             }
 286             else if (resolution == Resolution.HOUR)
 287             {
 288                 dt = dt.AddMinutes(0 - dt.Minute);
 289                 dt = dt.AddSeconds(0 - dt.Second);
 290                 dt = dt.AddMilliseconds(0 - dt.Millisecond);
 291             }
 292             else if (resolution == Resolution.MINUTE)
 293             {
 294                 dt = dt.AddSeconds(0 - dt.Second);
 295                 dt = dt.AddMilliseconds(0 - dt.Millisecond);
 296             }
 297             else if (resolution == Resolution.SECOND)
 298             {
 299                 dt = dt.AddMilliseconds(0 - dt.Millisecond);
 300             }
 301             else if (resolution == Resolution.MILLISECOND)
 302             {
 303                 // don't cut off anything
 304             }
 305             else
 306             {
 307                 throw new System.ArgumentException("unknown resolution " + resolution);
 308             }
 309             return dt.Ticks;
 310         }
 311
 312                 public class Resolution
 313                 {
 314                         public static readonly Resolution YEAR = new Resolution("year");
 315                         public static readonly Resolution MONTH = new Resolution("month");
 316                         public static readonly Resolution DAY = new Resolution("day");
 317                         public static readonly Resolution HOUR = new Resolution("hour");
 318                         public static readonly Resolution MINUTE = new Resolution("minute");
 319                         public static readonly Resolution SECOND = new Resolution("second");
 320                         public static readonly Resolution MILLISECOND = new Resolution("millisecond");
 321
 322                         private System.String resolution;
 323
 324                         internal Resolution()
 325                         {
 326                         }
 327
 328                         internal Resolution(System.String resolution)
 329                         {
 330                                 this.resolution = resolution;
 331                         }
 332
 333                         public override System.String ToString()
 334                         {
 335                                 return resolution;
 336                         }
 337                 }
 338         }
 339 }