Ejercicio 2

/*
 // Autor: Juan Antonio Ripoll
// Fecha: 03/10/2013

// Descripción:
/*
   REALIZA UN PROGRAMA EN JAVA QUE HAGA UNA COPIA DE UN FICHERO A OTRO DE 
   TODOS SUS DATOS. LOS NOMBRES DEL FICHERO A COPIAR SE LE PASARÁN COMO 
   PARÁMETRO.
*/

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main 
{
 public static void main(String[] args) throws IOException 
 {
  File file_in;
  File file_out;
  
  if (args.length != 2)
  {
   InputStreamReader c = new InputStreamReader(System.in); 
   BufferedReader in = new BufferedReader(c);
   
   System.out.print("Introduzca la ruta del archivo a copiar: "); 
   file_in = new File( in.readLine() );
   
   System.out.print("Introduzca la ruta del nuevo archivo: "); 
   file_out = new File( in.readLine() );
  }
  else
  {
   file_in = new File( args[0] );
   file_out = new File( args[1] );
  }
 
  System.out.println("Realizando copia de fichero un momento ...");
  
  try 
  {
   FileInputStream in = new FileInputStream(file_in);
   FileOutputStream out = new FileOutputStream(file_out);
   
   int i = 0;
   while(i != -1)
   {
    i = in.read();
    
    if (i != -1) out.write(i);
   }
   
   in.close(); out.close();
   
   System.out.println("La copia se realizó correctamente.");
  }
  catch(IOException e) 
  { 
   System.out.println("Error intentado realizar la copia del archivo.");
  }
 }

}

Ejercicio 1

/*
 * Autor: Juan Antonio Ripoll
 * 
 * REALIZA UN PROGRAMA EN JAVA QUE MUESTRE LOS FICHEROS DE UN DIRECTORIO. EL 
 * NOMBRE (DEL FICHERO O DIRECTORIO) SE PASARÁ COMO PARÁMETRO.
*/

import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.BufferedReader;

public class Main 
{
 public static void main(String[] args) throws IOException 
 {
  String path_file = null;
  
  if (args.length != 1)
  {
   System.out.print("Introduzca la ruta de un directorio/archivo: "); 
   
   InputStreamReader c = new InputStreamReader(System.in); 
   BufferedReader in = new BufferedReader(c);
   
   path_file = in.readLine();
  }
  else 
   path_file = args[0];
  
  
  File archivo = new File( path_file );
  
  if (archivo.isDirectory())
  {
   File[] archivos = archivo.listFiles();
   
   for (File a : archivos) {
    System.out.println(a.getName());
   } 
  }
 }
}

2.07 - Repeat until 0 do while

/*
 * Autor: Juan Antonio Ripoll
 * Date: 30/10/13
 * 
 * Create a JAVA program to ask the user for a number "x" and display 10*x. 
 * It must repeat until the user enters 0 (using "do-while"). 
 * */

import java.util.Scanner;

public class Main {

 public static void main(String[] args) {
  Scanner in = new Scanner(System.in);
  
  int number;
     do
     {
      System.out.print("Enter a number: ");
         number = in.nextInt();
         
      System.out.println(number*10); 
     }
     while (number != 0);
 }
}

2.06 - Repeat until 0

/*
 * Autor: Juan Antonio Ripoll
 * Date: 30/10/13
 * 
 * Create a JAVA program to ask the user for a number "x" 
 * and display 10*x. It must repeat until the user enters 0 (using "while"). 
 * */

import java.util.Scanner;

public class Main {

 public static void main(String[] args) {
  Scanner in = new Scanner(System.in);
  
  System.out.print("Enter a number: ");
  int number = in.nextInt();
  
     while (number != 0)
     {
      System.out.println(number*10);
      
      System.out.print("Enter a number: ");
         number = in.nextInt();
     }
 }
}

2.05 - Greatest of three numbers

/*
 * Autor: Juan Antonio Ripoll
 * Date: 30/10/13
 * 
 * Write a JAVA program to get three numbers 
 * from the user and display the greatest one. 
 * */

import java.util.Scanner;

public class Main {

 public static void main(String[] args) {
  Scanner in = new Scanner(System.in);
  
  System.out.print("Enter the first number: ");
  int number1 = in.nextInt();
  
  System.out.print("Enter the second number: ");
  int number2 = in.nextInt();
  
  System.out.print("Enter the third number: ");
  int number3 = in.nextInt();
  
  
  if (number1 > number2)
   if (number1 > number3)
    System.out.println("The greatest: " + number1);
  
  if (number2 > number1)
   if (number2 > number3)
    System.out.println("The greatest: " + number2);
  
  if (number3 > number1)
   if (number3 > number2)
    System.out.println("The greatest: " + number3);
 }
}

2.04 - Divide if not zero using else

/*
 * Autor: Juan Antonio Ripoll
 * Date: 30/10/13
 * 
 * Write a JAVA program to ask the user for two numbers, and show 
 * their division if the second number is not zero; otherwise, 
 * it will display "I cannot divide 
 * */

import java.util.Scanner;

public class Main {

 public static void main(String[] args) {
  Scanner in = new Scanner(System.in);
  
  System.out.print("Enter the first number: ");
  int number1 = in.nextInt();
  
  System.out.print("Enter the second number: ");
  int number2 = in.nextInt();
  
  
  if (number2!=0)
   System.out.print(number1 + " / " + number2 + " = " 
      + number1/number2);
  else
   System.out.print("I cannot divide.");
 }
}

2.03 - Divide if not zero

/*
 * Autor: Juan Antonio Ripoll
 * Date: 30/10/13
 * 
 * Write a JAVA program to ask the user for two numbers, and show 
 * their division if the second number is not zero; otherwise, 
 * it will display "I cannot divide 
 * */

import java.util.Scanner;

public class Main {

 public static void main(String[] args) {
  Scanner in = new Scanner(System.in);
  
  System.out.print("Enter the first number: ");
  int number1 = in.nextInt();
  
  System.out.print("Enter the second number: ");
  int number2 = in.nextInt();
  
  
  if (number2!=0)
   System.out.print(number1 + " / " + number2 + " = " 
      + number1/number2);
  else
   System.out.print("I cannot divide.");
 }
}