{"id":1513,"date":"2012-08-18T12:14:24","date_gmt":"2012-08-18T10:14:24","guid":{"rendered":"http:\/\/www.tutego.de\/blog\/javainsel\/?p=1513"},"modified":"2012-08-18T21:38:13","modified_gmt":"2012-08-18T19:38:13","slug":"snippet-kalender-ausdrucken-teil-2-von-bis","status":"publish","type":"post","link":"https:\/\/www.tutego.de\/blog\/javainsel\/2012\/08\/snippet-kalender-ausdrucken-teil-2-von-bis\/","title":{"rendered":"Snippet: Kalender ausdrucken, Teil 2: von-bis"},"content":{"rendered":"

Die erste Version meines Kalenderprogramms<\/a> druckte ein Kalender f\u00fcr ein Jahr. In Anwendungen d\u00fcrfte h\u00e4ufiger vorkommen, dass es ein Start- und Enddatum gibt, das auch \u00fcber Jahresgrenzen liegt. Das macht dieses Programm: <\/p>\n

public static class CalLine
{
  public int year;
  public int weekOfYear;
  public int month = -1;  \/\/ 0 <= month <= 11
  public int[] day = { -1, -1, -1, -1, -1, -1, -1 };
} <\/p>\n

public<\/span> static<\/span> List<CalLine> calenderOfTheYear( Date start, Date end )\n{\n  Calendar startCal = new<\/span> GregorianCalendar();\n  startCal.setTime( start );\n  Calendar endCal = new<\/span> GregorianCalendar();\n  endCal.setTime( end );\n  return<\/span> calenderOfTheYear( startCal, endCal );\n}\n\npublic<\/span> static<\/span> List<CalLine> calenderOfTheYear( Calendar start, Calendar end )\n{\n  List<CalLine> lines = new<\/span> ArrayList<>();\n\n  \/\/ Calender instances are mutable, so copy them<\/span>\n  Calendar startCal = (Calendar) start.clone(); \n  Calendar endCal   = (Calendar) end.clone(); \n\n  \/\/ For start date: first go backwards to the beginning of the month<\/span>\n  \/\/ then find monday of this week<\/span>\n  while<\/span> ( startCal.get( Calendar.DAY_OF_MONTH ) != 1 )\n    startCal.add( Calendar.DAY_OF_YEAR, -1 );\n  while<\/span> ( startCal.get( Calendar.DAY_OF_WEEK ) != Calendar.MONDAY )\n    startCal.add( Calendar.DAY_OF_YEAR, -1 );\n\n  \/\/ For end date: go forwards and find end of month<\/span>\n  \/\/ then find sunday of this week<\/span>\n  while<\/span> ( endCal.get( Calendar.DAY_OF_MONTH ) != startCal.getActualMaximum( Calendar.DAY_OF_MONTH ) )\n    endCal.add( Calendar.DAY_OF_YEAR, 1 );\n  while<\/span> ( endCal.get( Calendar.DAY_OF_WEEK ) != Calendar.SUNDAY )\n    endCal.add( Calendar.DAY_OF_YEAR, 1 );\n  endCal.add( Calendar.DAY_OF_YEAR, 1 );  \/\/ add 1 to test with < not <=<\/span>\n\n  CalLine line = new<\/span> CalLine();\n\n  while<\/span> ( startCal.before( endCal ) ) {\n    if<\/span> ( line.year == 0 )\n      line.year = startCal.get( Calendar.YEAR );\n    if<\/span> ( line.weekOfYear == 0 )\n      line.weekOfYear = startCal.get( Calendar.WEEK_OF_YEAR );\n\n    int<\/span> dayOfMonth = startCal.get( Calendar.DAY_OF_MONTH );\n    int<\/span> dayOfWeek  = startCal.get( Calendar.DAY_OF_WEEK );\n\n    if<\/span> ( dayOfMonth == 1 )\n      line.month = startCal.get( Calendar.MONTH );\n\n    line.day[dayOfWeek - 1] = dayOfMonth;\n\n    if<\/span> ( dayOfWeek == Calendar.SUNDAY ) {\n      \/\/ Days are Sun, Mon, ..., Sat. Rearange to Mon, ..., Sun <\/span>\n      int<\/span> first = line.day[ 0 ]; \/\/ This is faster then System.arraycopy()<\/span>\n      line.day[ 0 ] = line.day[ 1 ]; line.day[ 1 ] = line.day[ 2 ]; line.day[ 2 ] = line.day[ 3 ];\n      line.day[ 3 ] = line.day[ 4 ]; line.day[ 4 ] = line.day[ 5 ]; line.day[ 5 ] = line.day[ 6 ];\n      line.day[ 6 ] = first;\n\n      lines.add( line );\n      line = new<\/span> CalLine();   \/\/ it ends always with SUN, last line is not added<\/span>\n    }\n\n    startCal.add( Calendar.DAY_OF_YEAR, 1 );\n  }\n\n  return<\/span> lines;\n}<\/pre>\n