Esempi di sincronizzazione tra thread

src/com/oracle/java8/professional/concurrency/BankAccount.java

@@ -0,0 +1,19 @@
+package com.oracle.java8.professional.concurrency;
+
+public class BankAccount {
+    private long number;
+    private long balance;
+
+    public BankAccount(long number, long balance) {
+        this.number = number;
+        this.balance = balance;
+    }
+
+    public synchronized long getBalance() {
+        return balance;
+    }
+
+    public synchronized void deposit(long amout) {
+        balance += amout;
+    }
+}

src/com/oracle/java8/professional/concurrency/Data.java

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+package com.oracle.java8.professional.concurrency;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class Data {
+    private String packet;
+    private boolean transfer = true;
+
+    public synchronized void send(String packet) {
+        while (!transfer) {
+            try {
+                wait();
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                Logger.getAnonymousLogger().log(Level.SEVERE, "Interrupted error", e);
+            }
+        }
+
+        transfer = false;
+        this.packet = packet;
+        notifyAll();
+    }
+
+    public synchronized String receive() {
+        while (transfer) {
+            try {
+                wait();
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                Logger.getAnonymousLogger().log(Level.SEVERE, "Interrupted error", e);
+            }
+        }
+
+        transfer = true;
+        notifyAll();
+        return packet;
+    }
+
+}

src/com/oracle/java8/professional/concurrency/PingPong.java

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+package com.oracle.java8.professional.concurrency;
+
+public class PingPong extends Thread {
+    private String word;
+    private int delay;
+
+    public PingPong(String whatToSay, int delayTime) {
+        this.word = whatToSay;
+        this.delay = delayTime;
+    }
+
+    @Override
+    public void run() {
+        try {
+            for (;;) {
+                System.out.println(word + " ");
+                Thread.sleep(delay);
+            }
+        } catch (InterruptedException e) {
+            return;
+        }
+    }
+
+    public static void main(String[] args) {
+        System.out.println(Thread.currentThread().getName());
+        new PingPong("ping", 33).start();
+        new PingPong("PONG", 100).start();
+    }
+}

src/com/oracle/java8/professional/concurrency/Receiver.java

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+package com.oracle.java8.professional.concurrency;
+
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class Receiver implements Runnable {
+    private Data load;
+
+    public Receiver(Data data) {
+        this.load = data;
+    }
+
+    public void run() {
+        for (String receivedMessage = load.receive();
+             !"End".equals(receivedMessage);
+             receivedMessage = load.receive()) {
+
+            System.out.println(receivedMessage);
+
+            // ...
+            try {
+                Thread.sleep(ThreadLocalRandom.current().nextInt(1000, 5000));
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                Logger.getAnonymousLogger().log(Level.SEVERE, "Interrupted error", e);
+            }
+        }
+    }
+
+}

src/com/oracle/java8/professional/concurrency/Sender.java

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+package com.oracle.java8.professional.concurrency;
+
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class Sender implements Runnable {
+    private Data data;
+
+    public Sender(Data data) {
+        this.data = data;
+    }
+
+    @Override
+    public void run() {
+        String packets[] = {
+                "First packet",
+                "Second packet",
+                "Third packet",
+                "Fourth packet",
+                "End"
+        };
+
+        for (String packet : packets) {
+            data.send(packet);
+
+            // Thread.sleep() to mimic heavy server-side processing
+            try {
+                Thread.sleep(ThreadLocalRandom.current().nextInt(1000, 5000));
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                Logger.getAnonymousLogger().log(Level.SEVERE, "Interrupted error", e);
+            }
+        }
+    }
+
+}