Ex 21: On a single track two vehicles are running. As vehicles are going in same direction there is no problem. If the vehicles are running in different direction there is a chance of collision. To avoid collisions write a Java program using exception handling. You are free to make necessary assumptions.

import java.io.*;
class collision extends Exception
{
collision(String s)
{ super(s); }
}
class s06_04
{
public static void main(String ar[])
{
String t1=null,t2=null;
try
{
DataInputStream in= new DataInputStream(System.in);
System.out.println("enter the direction of vehicle1:(left/right):");
t1=in.readLine();
System.out.println("enter the direction of vehicle2:(left/right):");
t2=in.readLine();
if(!t1.equals(t2))
throw new collision("truck2 has to go on "+ t1 +" direction");
}
catch(collision e)
{
System.out.println(e);
t2=t1;
System.out.println("the collision has been avoided by redirection
truck2");
}
catch(Exception e)
{ System.out.println(e); }
System.out.println("direction of truck1 :"+t1);
System.out.println("direction of truck2 :"+t2);
}
}