[Ch15] Updated the synchronized version of Ryan and Monica so it actually works (076d08e2) · Commits · examples / Head First Java 3rd Edition

src/main/java/ch15/RyanAndMonicaSynchronizedTest.java

+21 −9

Changes for src/main/java/ch15/RyanAndMonicaSynchronizedTest.java: 21 added lines, 9 removed lines.
Original line number	Diff line number	Diff line
		@@ -2,10 +2,11 @@ package ch15;

		import java.util.concurrent.ExecutorService;
		import java.util.concurrent.Executors;
		import java.util.concurrent.TimeUnit;

		public class RyanAndMonicaSynchronizedTest {
		public static void main(String[] args) {
		BankAccount account = new BankAccount();
		public static void main(String[] args) throws InterruptedException {
		BankAccountSynchronized account = new BankAccountSynchronized();
		RyanAndMonicaSynchronizedJob ryan = new RyanAndMonicaSynchronizedJob("Ryan", account);
		RyanAndMonicaSynchronizedJob monica = new RyanAndMonicaSynchronizedJob("Monica", account);
		ExecutorService executor = Executors.newFixedThreadPool(2);
		@@ -17,35 +18,46 @@ public class RyanAndMonicaSynchronizedTest {

		class RyanAndMonicaSynchronizedJob implements Runnable {
		private final String name;
		private final BankAccount account;
		private final BankAccountSynchronized account;

		RyanAndMonicaSynchronizedJob(String name, BankAccount account) {
		RyanAndMonicaSynchronizedJob(String name, BankAccountSynchronized account) {
		this.name = name;
		this.account = account;
		}

		public void run() {
		for (int i = 0; i < 10; i++) {
		makeWithdrawal(10);
		account.makeWithdrawal(10, name);
		if (account.getBalance() < 0) {
		System.out.println("Overdrawn!");
		}
		}
		}
		}

		class BankAccountSynchronized {
		private int balance = 100;

		public int getBalance() {
		return balance;
		}

		private synchronized void makeWithdrawal(int amount) {
		if (account.getBalance() >= amount) {
		private void withdraw(int amount) {
		balance = balance - amount;
		}

		public synchronized void makeWithdrawal(int amount, String name) {
		if (balance >= amount) {
		System.out.println(name + " is about to withdraw");
		try {
		System.out.println(name + " is going to sleep");
		Thread.sleep(500);
		} catch (InterruptedException ex) {ex.printStackTrace();}
		System.out.println(name + " woke up.");
		account.withdraw(amount);
		withdraw(amount);
		System.out.println(name + " completes the withdrawal");
		} else {
		System.out.println("Sorry, not enough for " + name);
		}
		}
		}
		No newline at end of file

src/main/java/ch15/RyanAndMonicaTest.java

+1 −6

Changes for src/main/java/ch15/RyanAndMonicaTest.java: 1 added line, 6 removed lines.
Original line number	Diff line number	Diff line
		@@ -36,15 +36,10 @@ class RyanAndMonicaJob implements Runnable {

		class BankAccount {
		private int balance = 100;

		public int getBalance() {
		return balance;
		}

		private void withdraw(int amount) {
		balance = balance - amount;
		}

		public void makeWithdrawal(int amount, String name) {
		if (balance >= amount) {
		System.out.println(name + " is about to withdraw");
		@@ -53,7 +48,7 @@ class BankAccount {
		Thread.sleep(500);
		} catch (InterruptedException ex) {ex.printStackTrace();}
		System.out.println(name + " woke up.");
		withdraw(amount);
		balance = balance - amount;
		System.out.println(name + " completes the withdrawal");
		} else {
		System.out.println("Sorry, not enough for " + name);