Answer:
See explaination for thr program code.
Explanation:
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Scanner;
public class ReadWriteInt
{
public static void main(String args[]) throws IOException
{
Scanner input=new Scanner(System.in);
System.out.println("Enter the name of the input file:");
String inputFile=input.next();
System.out.println("Enter the name of the output file:");
String outputFile=input.next();
File fin=new File(inputFile);
File fout=new File(outputFile);
//print error, if input file does not exist
if(!fin.exists())
{
System.out.println("Error:Input file does not exist");
System.exit(0);
}
//print error, if output file does not exist
if(!fout.exists())
{
System.out.println("Error:output file does not exist");
System.exit(0);
}
//input stream to read
Scanner read=new Scanner(fin);
OutputStream os=new FileOutputStream(fout);
//output stream to write
PrintWriter write=new PrintWriter(os,true);
//read from input file until there are no numbers
while(read.hasNextLine())
{
String num=read.nextLine();
//convert the string into number
int number=Integer.parseInt(num);
//if the number is positive , write it to out put file
if(number>=0)
{
write.println(number);
System.out.println(number);
}
}
System.out.println("Positive numbers are copied successfully");
}
}
Please check attachment for screenshot and output
