Multithreading using Pipes Program

Question

Write a multi-threaded Java program to print all numbers below 100,000 that are
both prime and fibonacci number (some examples are 2, 3, 5, 13, etc.). Design a
thread that generates prime numbers below 100,000 and writes them into a pipe.
Design another thread that generates fibonacci numbers and writes them to another pipe. The main thread should read both the pipes to identify numbers common to both.

Program Written by Mr.G.Kumaresan sir.

Program

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

class Fibonacci extends Thread
{
private PipedWriter out = new PipedWriter();
public PipedWriter getPipedWriter()
{
return out;
}
public void run()
{
Thread t = Thread.currentThread();
t.setName("Fibonacci");
System.out.println(t.getName() + " thread started");
int fibo1=0,fibo2=1,fibo=0;
while(true)
{
try
{
fibo = fibo1 + fibo2;
if(fibo>100000)
{
out.close();
break;
}
out.write(fibo);
sleep(1000);
}
catch(Exception e)
{
System.out.println("Fibonacci:"+e);
}
fibo1=fibo2;
fibo2=fibo;
}
System.out.println(t.getName() + " thread exiting");

}
}
class Prime extends Thread
{
private PipedWriter out1 = new PipedWriter();
public PipedWriter getPipedWriter()
{
return out1;
}
public void run()
{
Thread t= Thread.currentThread();
t.setName("Prime");
System.out.println(t.getName() + " thread Started...");
int prime=1;
while(true)
{
try
{
if(prime>100000)
{
out1.close();
break;
}
if(isPrime(prime))
out1.write(prime);
prime++;
sleep(0);
}
catch(Exception e)
{
System.out.println(t.getName() + " thread exiting.");
System.exit(0);
}
}
}
public boolean isPrime(int n)
{
int m=(int)Math.round(Math.sqrt(n));
if(n==1 || n==2)
return true;
for(int i=2;i<=m;i++)
if(n%i==0)
return false;
return true;
}
}
public class PipedIo
{
public static void main(String[] args) throws Exception
{
Thread t=Thread.currentThread();
t.setName("Main");
System.out.println(t.getName() + " thread Started...");
Fibonacci fibonacci = new Fibonacci();
Prime prime = new Prime();
PipedReader fpr = new PipedReader(fibonacci.getPipedWriter());
PipedReader ppr = new PipedReader(prime.getPipedWriter());
fibonacci.start();
prime.start();
int fib=fpr.read(), prm=ppr.read();
System.out.println("The numbers common to PRIME and FIBONACCI:");
while((fib!=-1) && (prm!=-1))
{
while(prm<=fib)
{
if(fib==prm)
System.out.println(prm);
prm=ppr.read();
}
fib=fpr.read();
}
System.out.println(t.getName() + " thread exiting");
}
}

Download Source Code

PipedIo.java