Thread: Simple I/O Java Error

Im supposed to write this java program, and im having a problem, and I cannot figure out why I am getting an Unhandled Exception error.

I put a comment at the error line.

PrintWriter writer = new PrintWriter (writingfile); (Line where I am getting uNhandled exception error.)



Write a program that reads numeric operations from a
file and writes their result into another file.

Numbers & results are integer.
• Operators (+ - * / ) have equal precedence.
• Input file
• Name: “input.txt”
• There can be many operations, each on its own line, e.g.,
2 + 3 * 10 / 2
10 / 3 * 2
• Output file
• Name: “output.txt”
• The result of each operation is written in one line, e.g.,
25

Code ~

import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Scanner;
 
//There is NO PRECEDENCE in the math from the file
public class Operations {
public static void main (String [] args) {
 
	ArrayList<String> inputs = new ArrayList<String>();	
int [] array = new int[10]; //change this once the add to method works.
String k = "";
 
	try {	
 
		File inputfile = new File("math.txt");
		Scanner in = new Scanner (inputfile);
	while (in.hasNextLine()) {
		inputs.add (in.nextLine() );
	}
	in.close(); //all objects are inside of the ArrayList String type
 
	for (int i = 0; i < inputs.size(); i++) { //attempting to change from String to int
		k = inputs.get(i);
		array[i] = Integer.parseInt(k);
 
	}
		}
 
			catch (IOException e) {
			System.out.println("You done fucked up real good.");
	}
 
	File writingfile = new File ("output.txt");  //Writing to the file
	PrintWriter writer = new PrintWriter (writingfile);
 
	for (int i =0; i < array.length; i++ ) {
 
 
 
		writer.println(array[i]);
	}
	writer.close();
	}
 
 
	}

The file I ma reading the ints from looks like this. (named math.txt)

1+2*3/3
1+2+3+4*3/3
1+2+4

Help would be awesome. Thanks.

You do not need to parse the operators. You can leave them as a String or use charAt to get then as a char.