Re: Number format exception

From:
Ian Shef <invalid@avoiding.spam>
Newsgroups:
comp.lang.java.help
Date:
Tue, 08 Mar 2011 19:26:52 GMT
Message-ID:
<Xns9EA27EA03790Evaj4088ianshef@138.125.254.103>
Venki <meetuatvenki.com@gmail.com> wrote in news:cc15b0ba-88b8-4237-b6a2-
2277dd0f18f5@d12g2000prj.googlegroups.com:

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).
Note:
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.io.*;
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]);
               out.writeFloat(f);
          }
     }
     fr.close();
     out.close();
  }
}


Have you examined file input.txt ?
Have you tried adding
    System.out.println("s = " + s) ;
and
    System.out.printlnt("str["+i+"] = " + str[i]);

in appropriate places to examine what is happening?

My guess is that the regular expression that you are using to split lines
into words is wrong, but you have provided insufficient information for
verification.

Also...
The instructions said to "Use split method of String class". What you are
doing may be more efficient, but will your instructor accept your deviation
from the instructions?

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