Re: Number format exception

Knute Johnson <>
Tue, 08 Mar 2011 09:34:31 -0800
On 03/08/2011 09:15 AM, Venki wrote:

Can any one pls fix dis runtime error

/* Dealing with binary data:
Create a program to read a list of floating point numbers in a text
file and then write the data to a binary file.
  (Use classes: FileReader, FileBufferedReader, FileOutputStream,
String, Float, DataOutputStream).
Use FileReader and FileBufferedReader classes to be able to read each
line of the file as a string. Use split method of String class to
break the line into words.
Use Float.parseFloat to convert the string to floating point number.
Use FileOutputStream and DataOutputStream to write the float data as a
binary data to the file.

import java.util.regex.*;

public class readfloat {
   public static void main(String args[]) throws IOException {

    FileReader fr = new FileReader("input.txt");
    BufferedReader br = new BufferedReader(fr);
    String s;

    Pattern pat = Pattern.compile(", ");

    FileOutputStream fout = new FileOutputStream("output.txt");
    DataOutputStream out = new DataOutputStream(fout);
    while((s = br.readLine())!=null) {
        String str[] = pat.split(s);
        for(int i=0;i<str.length;i++){
            float f = Float.parseFloat(str[i]);

A NumberFormatException tells you that the String is not in a format
that can be converted to the appropriate number. So to debug, wrap your
call to parseFloat() in a try and print out the String in the catch and
you will see where your problem is hiding.


Knute Johnson

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