Monday, 13 July 2015

Java Programs[Important]

WRITE A JAVA PROGRAM to implement a Queue, using user defined Exception Handling (also make use of throw, throws).

Program :

import   .util.Scanner;

class ExcQueue extends Exception
 { 
ExcQueue(String s) super(s); 
}
 } 
{

class Queue
 { 
int front,rear;
 int q[ ]=new int[10];

Queue()
 { 
rear=-1; 
front=-1;

}

void enqueue(int n) throws ExcQueue 

if (rear==9)
 throw new ExcQueue("Queue is full");
 rear++; 
q[rear]=n; 
if (front==-1)
 front=0;
 }

int dequeue() throws ExcQueue
 { 
if (front==-1) throw new ExcQueue("Queue is empty"); 
int temp=q[front];
 if (front==rear)
 front=rear=-1; 
else front++; 
return(temp);
 }
 }


class UseQueue 
public static void main(String args[ ]) 
Queue a=new Queue(); 
try 
a.enqueue(5);
 a.enqueue(20); 
catch (ExcQueue e)
 {
 System.out.println(e.getMessage()); 
} try 
System.out.println(a.dequeue()); System.out.println(a.dequeue()); System.out.println(a.dequeue()); } catch(ExcQueue e) { System.out.println(e.getMessage()); } } }