sting tokenizer in a loop(vv urgent)

[rudolf hitler]

how can i use a string tokenizer in a loop.I need to read each line of a file and split it on a delimiter.
My txt file is in the format
A|B|C|D
i have used the following:
try
{
FileReader fr=new FileReader("myfile.txt");
BufferedReader br=new BufferedReader(fr);
while((line=br.readLine())!=null)
{
StringTokenizer st=new StringTokenizer(line,"|");
while (st.hasMoreTokens())
{
a=st.nextToken();
b=st.nextToken();
c=st.nextToken();
d=st.nextToken();
e=st.nextToken();
}
}
}catch(Exception ex){}
What happens is it reads one line then gives nosuchelementfound exception .can u suggest a way of gettin through this.Maybe i need to undefine st object at the end of the loop.If it is tht how do i undefine the object.

[sheril she]

instead of assigning the values of the tokens inside the loop use an array and use nextToken() only once within the loop.Use the array values to assign to a,b,...
for eg
int i=0;
StringTokenizer st=new StringTokenizer(line,"|");
while (st.hasMoreTokens())
{
ar[i]=st.nextToken();
i++;
}

[rudolf hitler]

tht doesnt help coz i had tried tht too before it keeps givin the exception no matter wht

[David O'Meara]

Not just urgent, not just very urgent, but more than very very urgent such that you don't have time to write 'very'? Must be important.
First you need to change your display name to comply with our Naming Policy. Accounts with invalid names get deleted, and you have 25 posts. You probably have one more chance before we delete your account.
Now we can get to your question:
Have you tried removing the inner loop that has the while(st.hasMoreTokens()) around it? Looking at what you're trying to do it doesn't look like it's required.
Dave

[Layne Lund]

Are you sure the StringTokenizer is throwing the exception? You should add some System.out.println() calls to find out how the flow of execution goes. This will give you a better idea of where the exception occurs.
HTH
Layne

[bob leduc]

add this within your code:
try{
while (st.hasMoreTokens())
{
a=st.nextToken();
b=st.nextToken();
c=st.nextToken();
d=st.nextToken();
e=st.nextToken();
}
} catch (NoSuchElementException e){}
Hope this works?

Originally posted by dimps:
how can i use a string tokenizer in a loop.I need to read each line of a file and split it on a delimiter.
My txt file is in the format
A|B|C|D
i have used the following:
try
{
FileReader fr=new FileReader("myfile.txt");
BufferedReader br=new BufferedReader(fr);
while((line=br.readLine())!=null)
{
StringTokenizer st=new StringTokenizer(line,"|");
while (st.hasMoreTokens())
{
a=st.nextToken();
b=st.nextToken();
c=st.nextToken();
d=st.nextToken();
e=st.nextToken();
}
}
}catch(Exception ex){}
What happens is it reads one line then gives nosuchelementfound exception .can u suggest a way of gettin through this.Maybe i need to undefine st object at the end of the loop.If it is tht how do i undefine the object.

[Bear Bibeault]

catch (NoSuchElementException e){}
Hope this works?

That won't do anything that the original code did not do, except for catching ONLY NoSuchElementExceptions.
The original code is getting the exception since the input string has 4 elements and you are calling the next method 5 times.
The code seems very confused. Why are you calling next multiple times in a loop? That makes no sense. If you know exactly how many elements will be retrived (apparently not) then there's no need for a loop. If you are going to loop, you should call the next method ONCE per loop and exit the loop when there are no more.
bear

[Jamie Robertson]

You have 4 tokens on a line, but you're calling nextToken() 5 times in each loop???
You probably want something like this:

try
{
   FileReader fr=new FileReader("myfile.txt");
   BufferedReader br=new BufferedReader(fr);
   while((line=br.readLine())!=null)
   {
      StringTokenizer st=new     
      StringTokenizer(line,"|");
      String[] tokens = new String[st.countTokens()];
      int i = 0;
      for( int i = 0; i < tokens.length; i++ )
      {
         tokens[i] = st.nextToken();
      }
   }
}catch(Exception ex){}

[David O'Meara]

Originally posted by Jamie Robertson:
You have 4 tokens on a line, but you're calling nextToken() 5 times in each loop???
[/CODE]

Correct. I spotted that too, but unfortunately I had to spent too much time doing administration stuff which cut into my helpful time.
I decided the bigger problem was that there was both a loop AND explicit calling of each element.

[Peter den Haan]

Erm, what's wrong with String.split()?
- Peter

[Neil Laurance]

Not everyone has Java 1.4 yet. I dont