generating soccer fixtures from a list of teams

public void createFixtureList()
{
//setup 'cal' to get todays date
Calendar cal = new GregorianCalendar();
int y = cal.get(Calendar.YEAR);
int m = cal.get(Calendar.MONTH); // 0=Jan, 1=Feb, ...
m++; // 1=Jan, 2=Feb,
....
int d = cal.get(Calendar.DAY_OF_MONTH);
int hr = 15;
int min = 00;

int j = league.size();
j--; // last club in league will have already had fixtures
generated by previous clubs
for (int i=0; i<j; i++)
{
//get a CLUB(i) and create all possible fixtures for it
Club c1 = (Club)league.get(i);
for (int x=i+1; x<league.size(); x++)
{
// get an opponent club - CLUB(x) to create 2 fixtures
(home/away) with club(i)
Club c2 = (Club)league.get(x);

// HOME GAME - CLUB(i) vs CLUB(x)
// set game date for one week after the previous club(i)
matchdate
d = d+7;
if (d > 23) // correct values 31->1
{
m++;
d=(d-30);
if (m > 11) // correct values dec->jan
{
m = 1;
y++;
}
}
Calendar homedate = new GregorianCalendar(y, m, d, hr, min);
Fixture f1 = new Fixture(c1.getGround(), homedate, c1, c2);
fixtures.add(f1);

// AWAY GAME CLUB(x) vs CLUB(i)
// set away game for 6 months later
int tempM = m;
int tempY = y;
m = (m+6);
if (m > 12)
{
m=(m-12);
y=y+1;
}
Calendar awaydate = new GregorianCalendar(y, m, d, hr, min);

Fixture f2 = new Fixture(c2.getGround(), awaydate, c2, c1);
fixtures.add(f2);

// return m and y back to previous CLUB(i) homegame value
m = tempM;
y = tempY;
homedate.clear();
homedate.set(y,m,d,hr,min);
}
}
printFixtureList();
}


For some reason, the above code worked perfectly when I had 3 clubs in the
league. But since I added a 4th club, I always get a runtime error.

It generates all fixtures ( for the first club (club(i)) perfectly. But
the problem occurs when it tries to increment i and get the next club to be
club(i). When it tries to get the club, it throws a 'null pointer
exception'. So the problem seems to be with the first FOR statement in the
above code.

zcraven

"zcraven" <> wrote in message
news:cltm1e$hr$...
> public void createFixtureList()
> {
> //setup 'cal' to get todays date
> Calendar cal = new GregorianCalendar();
> int y = cal.get(Calendar.YEAR);
> int m = cal.get(Calendar.MONTH); // 0=Jan, 1=Feb, ...
> m++; // 1=Jan, 2=Feb,
> ...
> int d = cal.get(Calendar.DAY_OF_MONTH);
> int hr = 15;
> int min = 00;
>
> int j = league.size();
> j--; // last club in league will have already had fixtures
> generated by previous clubs
> for (int i=0; i<j; i++)
> {
> //get a CLUB(i) and create all possible fixtures for it
> Club c1 = (Club)league.get(i);
> for (int x=i+1; x<league.size(); x++)
> {
> // get an opponent club - CLUB(x) to create 2 fixtures
> (home/away) with club(i)
> Club c2 = (Club)league.get(x);
>
> // HOME GAME - CLUB(i) vs CLUB(x)
> // set game date for one week after the previous club(i)
> matchdate
> d = d+7;
> if (d > 23) // correct values 31->1
> {
> m++;
> d=(d-30);
> if (m > 11) // correct values dec->jan
> {
> m = 1;
> y++;
> }
> }
> Calendar homedate = new GregorianCalendar(y, m, d, hr,
min);
> Fixture f1 = new Fixture(c1.getGround(), homedate, c1,
c2);
> fixtures.add(f1);
>
> // AWAY GAME CLUB(x) vs CLUB(i)
> // set away game for 6 months later
> int tempM = m;
> int tempY = y;
> m = (m+6);
> if (m > 12)
> {
> m=(m-12);
> y=y+1;
> }
> Calendar awaydate = new GregorianCalendar(y, m, d, hr,
min);
>
> Fixture f2 = new Fixture(c2.getGround(), awaydate, c2,
c1);
> fixtures.add(f2);
>
> // return m and y back to previous CLUB(i) homegame value
> m = tempM;
> y = tempY;
> homedate.clear();
> homedate.set(y,m,d,hr,min);
> }
> }
> printFixtureList();
> }
>
>
> For some reason, the above code worked perfectly when I had 3 clubs in the
> league. But since I added a 4th club, I always get a runtime error.
>
> It generates all fixtures ( for the first club (club(i)) perfectly. But
> the problem occurs when it tries to increment i and get the next club to
be
> club(i). When it tries to get the club, it throws a 'null pointer
> exception'. So the problem seems to be with the first FOR statement in
the
> above code.
>

correction - the problem is not accessing the clubs - it does that fine.
the problem is with updating the date values. when throws an 'error: month
cannot be zero or negative' error when it tries to create a fixture for the
2nd club vs the 3rd club in the league.

ok forget all that code before, it was crap. The problem is that it is not
updating the dates as I want it to. The first error (see printout below)
occurs here:

Man Utd vs Arsenal @ Old Trafford
24-May-2004 @ 15:00

(03-May-2004 @ 15:00 is correct)

Basically I want to create a whole fixture list, and I dont want the same
club to have two games on the same date. Whats wrong with my maths?

This is the code:


public void createFixtureList()
{
// set up todays date for later reference
Calendar today = new GregorianCalendar();
today.set(Calendar.MONTH, 2); //temp
today.set(Calendar.HOUR_OF_DAY, 15);
today.set(Calendar.MINUTE, 00);
today.set(Calendar.SECOND, 00);

//set up 'matchdate' as a date object with todays date, and 15:00
Calendar matchdate = new GregorianCalendar();
matchdate.set(Calendar.MONTH, 2); //temp
matchdate.set(Calendar.HOUR_OF_DAY, 15);
matchdate.set(Calendar.MINUTE, 00);
matchdate.set(Calendar.SECOND, 00);

int j = league.size();
j--; // no need to create fixtures for last club in league, as all
will have been generated already by previous clubs
for (int i=0; i<j; i++)
{
//get a CLUB(i) and create all possible fixtures for it
Club c1 = (Club)league.get(i);
System.out.println(" i=" + i);
for (int x=i+1; x<league.size(); x++)
{

// get an opponent club - CLUB(x) to create 2 fixtures
(home/away) with club(i)
Club c2 = (Club)league.get(x);

// HOME GAME - CLUB(i) vs CLUB(x)
// set game date for one week after the previous club(i)
matchdate (or today if this is 1st game)
matchdate.add(Calendar.DATE, 7);
Fixture f1 = new Fixture(c1.getGround(), matchdate, c1, c2);
fixtures.add(f1);
System.out.println(f1.getFixtureClubs() + " @ " +
f1.getFixturePlace());
f1.displayFixtureDate();

// AWAY GAME CLUB(x) vs CLUB(i)
// set away game for exactly 6 months after the home game
// awaydate = homedate;
matchdate.add(Calendar.MONTH, 6);
Fixture f2 = new Fixture(c2.getGround(), matchdate, c2, c1);
fixtures.add(f2);
System.out.println(f2.getFixtureClubs() + " @ " +
f2.getFixturePlace());
f2.displayFixtureDate();
matchdate.add(Calendar.MONTH, -6);
}
// before getting next club(i), give two weeks space to avoid
having 2 matches on the same date
matchdate = today;
matchdate.add(Calendar.DATE, 14);
System.out.println("reset date to today, then added 14");
}
printFixtureList();
}




this is the system.out:

[ league1.createFixtureList() ]
i=0

Liverpl vs Chelsea @ Anfield

05-Apr-2004 @ 15:00

Chelsea vs Liverpl @ chelseas ground

05-Oct-2004 @ 15:00

Liverpl vs Man Utd @ Anfield

12-Apr-2004 @ 15:00

Man Utd vs Liverpl @ Old Trafford

12-Oct-2004 @ 15:00

Liverpl vs Arsenal @ Anfield

19-Apr-2004 @ 15:00

Arsenal vs Liverpl @ Highbury

19-Oct-2004 @ 15:00

Liverpl vs Newcastle @ Anfield

26-Apr-2004 @ 15:00

Newcastle vs Liverpl @ St.James Park

26-Oct-2004 @ 15:00

reset date to today, then added 14

i=1

Chelsea vs Man Utd @ chelseas ground

19-Apr-2004 @ 15:00

Man Utd vs Chelsea @ Old Trafford

19-Oct-2004 @ 15:00

Chelsea vs Arsenal @ chelseas ground

26-Apr-2004 @ 15:00

Arsenal vs Chelsea @ Highbury

26-Oct-2004 @ 15:00

Chelsea vs Newcastle @ chelseas ground

03-May-2004 @ 15:00

Newcastle vs Chelsea @ St.James Park

03-Nov-2004 @ 15:00

reset date to today, then added 14

i=2

Man Utd vs Arsenal @ Old Trafford

24-May-2004 @ 15:00

Arsenal vs Man Utd @ Highbury

24-Nov-2004 @ 15:00

Man Utd vs Newcastle @ Old Trafford

31-May-2004 @ 15:00

Newcastle vs Man Utd @ St.James Park

30-Nov-2004 @ 15:00

reset date to today, then added 14

i=3

Arsenal vs Newcastle @ Highbury

20-Jun-2004 @ 15:00

Newcastle vs Arsenal @ St.James Park

20-Dec-2004 @ 15:00

reset date to today, then added 14

zcraven wrote:
> ok forget all that code before, it was crap. The problem is that it is not
> updating the dates as I want it to. The first error (see printout below)
> occurs here:
>
> Man Utd vs Arsenal @ Old Trafford
> 24-May-2004 @ 15:00
>
> (03-May-2004 @ 15:00 is correct)
>
> Basically I want to create a whole fixture list, and I dont want the same
> club to have two games on the same date. Whats wrong with my maths?
>
> This is the code:
>
>
> public void createFixtureList()
> {
> // set up todays date for later reference
> Calendar today = new GregorianCalendar();
> today.set(Calendar.MONTH, 2); //temp
> today.set(Calendar.HOUR_OF_DAY, 15);
> today.set(Calendar.MINUTE, 00);
> today.set(Calendar.SECOND, 00);
>
> //set up 'matchdate' as a date object with todays date, and 15:00
> Calendar matchdate = new GregorianCalendar();
> matchdate.set(Calendar.MONTH, 2); //temp
> matchdate.set(Calendar.HOUR_OF_DAY, 15);
> matchdate.set(Calendar.MINUTE, 00);
> matchdate.set(Calendar.SECOND, 00);
>
> int j = league.size();
> j--; // no need to create fixtures for last club in league, as all
> will have been generated already by previous clubs
> for (int i=0; i<j; i++)
> {
> //get a CLUB(i) and create all possible fixtures for it
> Club c1 = (Club)league.get(i);
> System.out.println(" i=" + i);
> for (int x=i+1; x<league.size(); x++)
> {
>
> // get an opponent club - CLUB(x) to create 2 fixtures
> (home/away) with club(i)
> Club c2 = (Club)league.get(x);
>
> // HOME GAME - CLUB(i) vs CLUB(x)
> // set game date for one week after the previous club(i)
> matchdate (or today if this is 1st game)
> matchdate.add(Calendar.DATE, 7);
> Fixture f1 = new Fixture(c1.getGround(), matchdate, c1, c2);
> fixtures.add(f1);
> System.out.println(f1.getFixtureClubs() + " @ " +
> f1.getFixturePlace());
> f1.displayFixtureDate();
>
> // AWAY GAME CLUB(x) vs CLUB(i)
> // set away game for exactly 6 months after the home game
> // awaydate = homedate;
> matchdate.add(Calendar.MONTH, 6);
> Fixture f2 = new Fixture(c2.getGround(), matchdate, c2, c1);
> fixtures.add(f2);
> System.out.println(f2.getFixtureClubs() + " @ " +
> f2.getFixturePlace());
> f2.displayFixtureDate();
> matchdate.add(Calendar.MONTH, -6);
> }
> // before getting next club(i), give two weeks space to avoid
> having 2 matches on the same date
> matchdate = today;
> matchdate.add(Calendar.DATE, 14);
> System.out.println("reset date to today, then added 14");
> }
> printFixtureList();
> }
>
>
>
>
> this is the system.out:
>
> [ league1.createFixtureList() ]
> i=0
>
> Liverpl vs Chelsea @ Anfield
>
> 05-Apr-2004 @ 15:00
>
> Chelsea vs Liverpl @ chelseas ground
>
> 05-Oct-2004 @ 15:00
>
> Liverpl vs Man Utd @ Anfield
>
> 12-Apr-2004 @ 15:00
>
> Man Utd vs Liverpl @ Old Trafford
>
> 12-Oct-2004 @ 15:00
>
> Liverpl vs Arsenal @ Anfield
>
> 19-Apr-2004 @ 15:00
>
> Arsenal vs Liverpl @ Highbury
>
> 19-Oct-2004 @ 15:00
>
> Liverpl vs Newcastle @ Anfield
>
> 26-Apr-2004 @ 15:00
>
> Newcastle vs Liverpl @ St.James Park
>
> 26-Oct-2004 @ 15:00
>
> reset date to today, then added 14
>
> i=1
>
> Chelsea vs Man Utd @ chelseas ground
>
> 19-Apr-2004 @ 15:00
>
> Man Utd vs Chelsea @ Old Trafford
>
> 19-Oct-2004 @ 15:00
>
> Chelsea vs Arsenal @ chelseas ground
>
> 26-Apr-2004 @ 15:00
>
> Arsenal vs Chelsea @ Highbury
>
> 26-Oct-2004 @ 15:00
>
> Chelsea vs Newcastle @ chelseas ground
>
> 03-May-2004 @ 15:00
>
> Newcastle vs Chelsea @ St.James Park
>
> 03-Nov-2004 @ 15:00
>
> reset date to today, then added 14
>
> i=2
>
> Man Utd vs Arsenal @ Old Trafford
>
> 24-May-2004 @ 15:00
>
> Arsenal vs Man Utd @ Highbury
>
> 24-Nov-2004 @ 15:00
>
> Man Utd vs Newcastle @ Old Trafford
>
> 31-May-2004 @ 15:00
>
> Newcastle vs Man Utd @ St.James Park
>
> 30-Nov-2004 @ 15:00
>
> reset date to today, then added 14
>
> i=3
>
> Arsenal vs Newcastle @ Highbury
>
> 20-Jun-2004 @ 15:00
>
> Newcastle vs Arsenal @ St.James Park
>
> 20-Dec-2004 @ 15:00
>
> reset date to today, then added 14
>
>
>
>
>

No suprise that the issue happens when Arsenal is playng Man U

matchdate = today hmmm.. aren't you then moving today when playing with
matchdate afterwards? I would clone().

bruno