1  import java.io.InputStream;
  2  import java.io.IOException;
  3  import java.io.OutputStream;
  4  import java.io.PrintWriter;
  5  import java.net.Socket;
  6  import java.util.Scanner;
  7  
  8  /**
  9     Executes Simple Bank Access Protocol commands
 10     from a socket.
 11  */
 12  public class BankService implements Runnable
 13  {
 14     private Socket s;
 15     private Scanner in;
 16     private PrintWriter out;
 17     private Bank bank;
 18  
 19     /**
 20        Constructs a service object that processes commands
 21        from a socket for a bank.
 22        @param aSocket the socket
 23        @param aBank the bank
 24     */
 25     public BankService(Socket aSocket, Bank aBank)
 26     {
 27        s = aSocket;
 28        bank = aBank;
 29     }
 30  
 31     public void run()
 32     {
 33        try
 34        {
 35           try
 36           {
 37              in = new Scanner(s.getInputStream());
 38              out = new PrintWriter(s.getOutputStream());
 39              doService();            
 40           }
 41           finally
 42           {
 43              s.close();
 44           }
 45        }
 46        catch (IOException exception)
 47        {
 48           exception.printStackTrace();
 49        }
 50     }
 51  
 52     /**
 53        Executes all commands until the QUIT command or the
 54        end of input.
 55     */
 56     public void doService() throws IOException
 57     {      
 58        while (true)
 59        {  
 60           if (!in.hasNext()) return;
 61           String command = in.next();
 62           if (command.equals("QUIT")) return;         
 63           else executeCommand(command);
 64        }
 65     }
 66  
 67     /**
 68        Executes a single command.
 69        @param command the command to execute
 70     */
 71     public void executeCommand(String command)
 72     {
 73        int account = in.nextInt();
 74        if (command.equals("DEPOSIT"))
 75        {
 76           double amount = in.nextDouble();
 77           bank.deposit(account, amount);
 78        }
 79        else if (command.equals("WITHDRAW"))
 80        {
 81           double amount = in.nextDouble();
 82           bank.withdraw(account, amount);
 83        }      
 84        else if (!command.equals("BALANCE"))
 85        {
 86           out.println("Invalid command");
 87           out.flush();
 88           return;
 89        }
 90        out.println(account + " " + bank.getBalance(account));
 91        out.flush();
 92     }
 93  }