Calculate Yesterday's Date

[rockies1]

I have the following code for calculating yesterday's date:

public static String CalcYestDate()
{
	//Set up date to run for
	java.util.Calendar  gc;
	java.util.Date  curDate;
	String  strCurDate = null;
	String fileDate = new String();

	gc = GregorianCalendar.getInstance ( ); // Gets the current Calendar instance
	gc.roll(gc.DATE,false);
	
	curDate = gc.getTime ( ); // Gets the Date time part of gc
	SimpleDateFormat sdf2 = new SimpleDateFormat ( "MMddyy" ); //sets up the correct format for the date
	fileDate = sdf2.format ( curDate );  //Changes the date into the correct date format
			
	return(fileDate);
}//End CalcYestDate

Yesterday, however, it calculated 083104 instead of 073104.

Anyone know of a more accurate method?

[Dillinger4]

It's pretty stupid that Calendars getTime() returns a Date object
when most of the methods within the Date class are deprecated.
Anyway.....

 import java.util.*; 
 import java.text.*; 

 public class CalDate{
  public static void main(String[] args){
    Calendar  gc;
    Date  curDate;
    String  strCurDate = null;
    String fileDate = new String();
    SimpleDateFormat sdf2 = new SimpleDateFormat("MMddyy");
    gc = GregorianCalendar.getInstance();

    curDate = gc.getTime();
    fileDate = sdf2.format(curDate);
    System.out.println(fileDate);

    gc.setTimeInMillis(gc.getTimeInMillis() - 86400000);

    curDate = gc.getTime();
    fileDate = sdf2.format(curDate);
    System.out.println(fileDate);
  } 
 }

[rockies1]

Eclipse doesn't like

gc.setTimeInMillis

I found this code that I had for another old project that I'll try and modify:

import java.text.SimpleDateFormat;
import java.util.*; 
import java.text.*;

public class DateTest
{

    public static void main(String[] args)
    {
		for(int i = 0;i<365;i++)
		{
		    System.out.println(DateRoller("20040804",i));
		}
    }
    public static String DateRoller(String strDate, int intDaysToRoll)
    {
    	java.util.Date  curDate;
    	SimpleDateFormat sdf2 = new SimpleDateFormat ("yyyyMMdd");
    	Date dtTemp = new Date();		
    	try
    	{
    		dtTemp = sdf2.parse(strDate);			
    	}
    	catch(ParseException e){}
    	
    	int y = dtTemp.getYear()+1900;
    	int m = dtTemp.getMonth();
    	int d = dtTemp.getDate();
    	java.util.GregorianCalendar rcal = new GregorianCalendar(y,m,d);
    	curDate = rcal.getTime ( );
    	long msYDate = 0;
    	long msCDate = curDate.getTime();
    	msYDate = msCDate;
    	//Transforms the current date into miliseconds
    	for(int i = 0;i<intDaysToRoll;i++)
    	{
    		msYDate = msYDate - 86400000; // Subtracts off X day's worth of miliseconds
    	}
    	java.util.Date yestDate = new java.util.Date (msYDate); 			
    	return sdf2.format(yestDate);
    } //End DateRoller
}