bankoperation.java

Java Classic Examples是我买的两本书：《JAVA经典实例》和《java入门经典源代码》里边附送光盘里带的源码

import java.util.Random;

public class BankOperation
{
  public static void main(String[] args)
  {
    int initialBalance = 500;     // The initial account balance
    int totalCredits = 0;         // Total credits on the account
    int totalDebits =0;           // Total debits on the account
    int transactionCount = 20;    // Number of debits and of credits

    // Create the bank, the clerks, and the account...
    Bank theBank = new Bank();                       // Create a bank
    Clerk clerk1 = new Clerk(theBank);               // Create the first clerk
    Clerk clerk2 = new Clerk(theBank);               // Create the second clerk
    Account account = new Account(1, initialBalance);// Create an account

    // Create the threads for the clerks as daemon, and start them off
    Thread clerk1Thread = new Thread(clerk1);
    Thread clerk2Thread = new Thread(clerk2);
    clerk1Thread.setDaemon(true);                    // Set first as daemon
    clerk2Thread.setDaemon(true);                    // Set second as daemon
    clerk1Thread.start();                            // Start the first
    clerk2Thread.start();                            // Start the second

    // Generate transactions of each type and pass to the clerks
    Random rand = new Random();                      // Random number generator
    Transaction transaction;                         // Stores a transaction
    int amount;                                      // stores an amount of money
    for(int i = 1; i <= transactionCount; i++)
    {
      amount = 50 + rand.nextInt(26);                // Generate amount of $50 to $75
      transaction = new Transaction(account,            // Account
                                    Transaction.CREDIT, // Credit transaction
                                    amount);            //  of amount
      totalCredits += amount;                    // Keep total credit tally

      // Wait until the first clerk is free
      while(clerk1.isBusy())
      try 
      {
        Thread.sleep(25);                            // Busy so try later
      }
       catch(InterruptedException e)
      {
        System.out.println(e);
      }

      clerk1.doTransaction(transaction);             // Now do the credit
    
      amount = 30 + rand.nextInt(31);                // Generate amount of $30 to $60
      transaction = new Transaction(account,            // Account
                                    Transaction.DEBIT,  // Debit transaction
                                    amount);            //  of amount
      totalDebits += amount;                         // Keep total debit tally

      // Wait until the second clerk is free
      while(clerk2.isBusy())
      try 
      {
        Thread.sleep(25);                            // Busy so try later
      }
      catch(InterruptedException e)
      {
        System.out.println(e);
      }

      clerk2.doTransaction(transaction);             // Now do the debit
    }

    // Wait until both clerks are done
    while(clerk1.isBusy() || clerk2.isBusy())
    try
    {
      Thread.sleep(25);
    }
    catch(InterruptedException e)
    {
      System.out.println(e);
    }

    // Now output the results
    System.out.println(
          "Original balance    : $" + initialBalance+"\n" +
          "Total credits       : $" + totalCredits+"\n" +
          "Total debits        : $" + totalDebits+"\n" +
          "Final balance       : $" + account.getBalance() + "\n" +
          "Should be           : $" + (initialBalance + totalCredits - 
                                                            totalDebits));
  }
}