Question 3

import java.io.*;
class CopyFileInJavaH2E
{
	public static void main(String args[]) throws IOException
	{
		int ch;
		FileInputStream fin = new FileInputStream("File1.txt");
		BufferedInputStream bfin = new BufferedInputStream(fin);
		FileOutputStream fout = new FileOutputStream("File2.txt");
		BufferedOutputStream bfout = new BufferedOutputStream(fout);
		while((ch=bfin.read()) != -1)
			bfout.write(ch);
		bfin.close();
		bfout.close();			
	}
}

abstract class Shape
{
	double dimension1,dimension2,radius;
	abstract double area();
}
class Triangle extends Shape
{
	Triangle(double d1,double d2)
	{
		dimension1=d1;
		dimension2=d2;
	}
	double area()
	{
		System.out.print("Area Of Triangle : ");
		return ((dimension1*dimension2)/2);
	}
}
class Rectangle extends Shape
{
	Rectangle(double d1,double d2)
	{
		dimension1=d1;
		dimension2=d2;
	}
	double area()
	{
		System.out.print("Area Of Rectangle : ");
		return (dimension1*dimension2);
	}
}
class Circle extends Shape
{
	Circle(double d1)
	{
		radius = d1;
	}
	double area()
	{
		System.out.print("Area Of Circle : ");
		return ((22*radius*radius)/7);
	}
}
class AbstractClassWithSubclassExampleH2E
{
	public static void main(String args[])
	{
		Triangle t = new Triangle(25,20);
		Rectangle r = new Rectangle(15,20);
		Circle c = new Circle(49);
		Shape shapeRef;
		shapeRef = t;
		System.out.println(shapeRef.area());
		System.out.println();
		shapeRef = r;
		System.out.println(shapeRef.area());
		System.out.println();		
		shapeRef = c;
		System.out.println(shapeRef.area());
	}
}

            

import java.io.*;
public class RandomAccessFileExampleH2E{
	public static void main(String[] args) throws IOException{
		File file = new File(args[0]);
		if(!file.exists())
		{
			System.out.println("File does not exist.");
			System.exit(0);
		}
		try{
			//Open the file for both reading and writing
			RandomAccessFile rand = new RandomAccessFile(file,"r"); 
			int i=(int)rand.length();
			System.out.println("Length: " + i);
   			
			for(int ct = (i-1); ct > 0; ct--){
				rand.seek(ct);
				byte b = rand.readByte();
				System.out.print(b); //read the character
			}
			rand.close();
		}
			catch(IOException e)
		{
		System.out.println(e.getMessage());
		}
	}
}

            

interface P
{
	public static final int p = 5;
	void methodP();
}
interface P1 extends P
{
	public static final int p1 = 10;
	void methodP1();
}
interface P2 extends P
{
	public static final int p2 = 15;
	void methodP2();
}
interface P12 extends P1,P2
{
	public static final int p12 = 20;
	void methodP12();
} 
class Q implements P12
{
	public void methodP12()
	{
		System.out.println("P12 class's method and Constant : "+p12);
	}
	public void methodP1()
	{
		System.out.println("P1 class's method and Constant : "+p1);	
	}
	public void methodP2()
	{
		System.out.println("P2 class's method and Constant : "+p2);	
	}
	public void methodP()
	{
		System.out.println("P class's method and Constant : "+p);	
	}
}
class InterfaceWithInheritanceExampleH2E
{
	public static void main(String args[])
	{
		Q obj = new Q();
		obj.methodP12();
		obj.methodP1();
		obj.methodP2();
		obj.methodP();		
	}
}