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, 800};  // The initial account balances
    int[] totalCredits = new int[initialBalance.length];  // Total cr's
    int[] totalDebits = new int[initialBalance.length];   // Total db's
    int transactionCount = 20;          // Number of debits and of credits

    // Create the bank and the clerks...
    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

    // Create the accounts, and initialize total credits and debits
    Account[] accounts = new Account[initialBalance.length]; 
    for(int i = 0; i < initialBalance.length; i++)
    {
      accounts[i] = new Account(i+1, initialBalance[i]); // Create accounts
      totalCredits[i] = totalDebits[i] = 0;
    }

    // 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
    int select;                                      // Selects an account
    for(int i = 1; i <= transactionCount; i++)
    {
      // Generate a random account index for credit operation
      select = rand.nextInt(accounts.length);
      amount = 50 + rand.nextInt(26);                // Generate amount of $50 to $75
      transaction = new Transaction(accounts[select],       // Account
                                        Transaction.CREDIT, // Credit transaction
                                        amount);            //  of amount
      totalCredits[select] += amount;                // Keep total credit tally
   
      clerk1.doTransaction(transaction);             // Now do the credit

      // Generate a random account index for debit operation
      select = rand.nextInt(accounts.length);
      amount = 30 + rand.nextInt(31);                // Generate amount of $30 to $60
      transaction = new Transaction(accounts[select],   // Account
                                Transaction.DEBIT,  // Debit transaction
                                amount);            //  of amount
      totalDebits[select] += amount;                 // Keep total debit tally

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

    // Wait until both clerks are done
    clerk1.isBusy();
    clerk2.isBusy();

    // Now output the results
    for(int i = 0; i < accounts.length; i++)   
      System.out.println("Account Number:"+accounts[i].getAccountNumber()+"\n"+
         "Original balance    : $" + initialBalance[i] + "\n" +
         "Total credits       : $" + totalCredits[i] + "\n" +
         "Total debits        : $" + totalDebits[i] + "\n" +
         "Final balance       : $" + accounts[i].getBalance() + "\n" +
         "Should be           : $" + (initialBalance[i] + totalCredits[i] -
                                                     totalDebits[i]) + "\n");
  }
}