/* From: "COMPUTATIONAL PHYSICS, 2nd Ed" 
   by RH Landau, MJ Paez, and CC Bordeianu 
   Copyright Wiley-VCH, 2007.
   Electronic Materials copyright: R Landau, Oregon State Univ, 2007;
   MJ Paez, Univ Antioquia, 2007; and CC Bordeianu, Univ Bucharest, 2007.
   Support by National Science Foundation                              
*/
// AreaScanner: examples of use of Scanner and printf (JDK 1.5)

import java.io.*;                             // Standard I/O classes
import java.util.*;                                  // scanner class

public class Area_Scanner  { 
	public static final double PI = 3.141593;              // Constants
  
	public static void main(String[] argv) throws 
                     IOException, FileNotFoundException { 
											 
	  double r, A;                                  
		                                     // Connect Scanner to std in
    Scanner sc1 = new Scanner(System.in);
    System.out.println("Key in your name & r on 1 or more lines"); 
		                                      // Read String, read double
    String name = sc1.next();                          
    r = sc1.nextDouble();                              
    System.out.printf("Hi "+name);
    System.out.printf("\n radius = "+r); 
    System.out.printf("\n\n Enter new name and r in Name.dat\n");
		                                                    // Input file
    Scanner sc2 = new Scanner(new File("Name.dat"));     // Open file
    System.out.printf("Hi %s\n",sc2.next());      // Read, print ln 1
    r = sc2.nextDouble();                                // Read ln 2
    System.out.printf("r = %5.1f\n",r);                 // Print ln 2
		
    A = PI * r * r;                                     
    System.out.printf("Done, look in A.dat\n");    // Print to screen
		                                              // Open output file
    PrintWriter q = new PrintWriter                    
		    (new FileOutputStream("A.dat"), true);
    q.printf("r = %5.1f\n" ,r);                        // File output
    q.printf("A = %8.3f\n",A);  
    System.out.printf("r = %5.1f\n" , r);            // Screen output
    System.out.printf("A = %8.3f\n" , A);  
		                                                 // Integer input
    System.out.printf("\n\n Now key in your age as an integer\n"); 
    int age = sc1.nextInt();                             //  Read int
    System.out.printf(age+"years old, you don't look it!" );
    sc1.close(); sc2.close();                         // Close inputs
  } 
}