Thread: Need Help with StringTokenizer.

I am having trouble with StringTokenizer. I have an input file that has an infix expressions followed by
a set of numbers which are the values for the variables

A + B * C
1 3 5 2 2 2

The goal is to take the infix and convert it to postfix. Then you will take the postfix and using the numbers evaluate the postfix expression. I have most of the methods completed to do the conversions and evaluations. My problem is getting the data out of the files.

I need to read the infix, print to an output file the infix, the postfix conversion, the values for the variables and the evaluated expression value.

I have my stacks, & queues set up. I just need help getting the data from the file.
StringTokenizer gives me tokens in strings but, I need to get characters and ints.
This is only a snippet of my full code but, it compiles but will not run.

Can anyone help with my use of StringTokenizer?

while(inFile.hasNext())
{
 
       line = inFile.nextLine();
       st = new StringTokenizer(line);
      while(st.hasMoreTokens())
      {
         test = st.nextToken();
         //ops = st.nextToken.charAt(0);
         numbers = Integer.parseInt((st.nextToken()));
 
      }
 
}

I understand this. I can not figure out how to go through the file.
the way I wrote the while loop
test = st.nextToken();

grabs the next token which is A


numbers = Integer.parseInt((st.nextToken()));
trys to grab "+" which is not an int then crashes.

I am not sure how to process the file to get what I want. Do I need another loop in there?

Im not trying to parse it into an int. The code is wrong. I am asking what I need to do to read the first line which will be an expression.

Then read the second line which are numbers and parse those to ints and continue till the end the file.

The file is an expression on one line then numbers on the next.

Im trying to do this but I am a still having problems because I still have strings. I need the infix expression to be in a character array to pass to my methods and the numbers to be integers to pass to my methods.