Hum, what's wrong here?

Here is the output:

import java.util.Scanner;
import java.io.*;

public class Gen {

public String file;
public static Scanner txt;

public Gen() {

try{
System.out.print("enter local file to read: ");
Scanner scan = new Scanner(System.in);
file = scan.next();
scan.close();
txt = new Scanner(new FileReader(file));

} catch (Exception ex) {

System.out.println("file not found");
System.exit(0);
  }

System.out.println();

int i = 0;

while(txt.hasNext()) {
i++;
txt.next();
}

txt.close();
txt = null;

try {
txt = new Scanner(new FileReader(file));
} catch (Exception e) {
System.exit(0); 
}

String[] fileArray = new String[i];

int j = 0;

while(txt.hasNext())
fileArray[j] = txt.next();

txt.close();
txt = null;

System.out.println("local file array populated: " + i + " words. . .");
System.out.println();

Scanner console = new Scanner(System.in);
System.out.print("enter number of lines, 0 to quit: ");

int f = console.nextInt();

System.out.println();

if(f == 0)
System.exit(0);

for(int a = 0; a < f; a++) {
for(int b = 0; b < 10; b++) {
System.out.print(fileArray[(int)(Math.random() * i)] + " ");
System.out.println();

}
}
}

public static void main(String[] args) {
new Gen();

}

I haven't tried to use Scanner with System.in, but my guess would be that the call to nextInt expects a number to be available already, and since there is none, it throws an exception. In other words, the call doesn't wait until there is an int. Have a look at the hasNextInt method to see whether there actually is an int available.

And please UseAMeaningfulSubjectLine
[ January 13, 2007: Message edited by: Ulf Dittmer ]

In general, nextInt() would block waiting for new input. The problem here is that System.in has already been closed, near the top of the method. Closing the scanner also closes the stream it's wrapped around. Once it's been closed, you can't reopen it. So when you later create a new Scanner wrapped around System.in, it can't possibly read anything - hence, the error you've gotten.

If you want to use System.in more than once, you need to create a single Scanner for reading System.in, and keep using it. Don't close it until you're really done with it, and don't try to create a new one.

thanks