添加corejava第11版源码

日期：2019-5-22

corejava第11版/v1ch12/threads/Bank.java

@@ -0,0 +1,61 @@
+package threads;
+
+import java.util.*;
+
+/**
+ * A bank with a number of bank accounts.
+ */
+public class Bank
+{
+   private final double[] accounts;
+
+   /**
+    * Constructs the bank.
+    * @param n the number of accounts
+    * @param initialBalance the initial balance for each account
+    */
+   public Bank(int n, double initialBalance)
+   {
+      accounts = new double[n];
+      Arrays.fill(accounts, initialBalance);
+   }
+
+   /**
+    * Transfers money from one account to another.
+    * @param from the account to transfer from
+    * @param to the account to transfer to
+    * @param amount the amount to transfer
+    */
+   public void transfer(int from, int to, double amount)
+   {
+      if (accounts[from] < amount) return;
+      System.out.print(Thread.currentThread());
+      accounts[from] -= amount;
+      System.out.printf(" %10.2f from %d to %d", amount, from, to);
+      accounts[to] += amount;
+      System.out.printf(" Total Balance: %10.2f%n", getTotalBalance());
+   }
+
+   /**
+    * Gets the sum of all account balances.
+    * @return the total balance
+    */
+   public double getTotalBalance()
+   {
+      double sum = 0;
+
+      for (double a : accounts)
+         sum += a;
+
+      return sum;
+   }
+
+   /**
+    * Gets the number of accounts in the bank.
+    * @return the number of accounts
+    */
+   public int size()
+   {
+      return accounts.length;
+   }
+}