Initial Commit

Author: aditya-sridhar

.gitignore

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+out
+.idea/
+*.iml

README.md

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+# How to use Synchronized keyword in Java
+
+This code is part of a blog post.
+
+The link to the blog post is given here.
+
+Read the blog post to make the best use of this repo :)
+
+
+## Cloning the code to your local
+
+Clone this code to your local using the following command
+
+```bash
+git clone https://github.com/aditya-sridhar/java-threads-synchronized-example.git
+```
+
+Or you can import the project into an IDE of your choice. I Used Eclipse to test this out
+
+## Run the Application
+
+Each Code in this Repo has a **main()** function. So each code can be run independently.

src/SynchronizedCustomObjectDemo.java

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+/**
+ * Utility to print from 0 to 5
+ */
+class PrintUtilExample3 {
+
+    //object to store the synchronized lock
+    final Object lockObject = new Object();
+
+    /**
+     * Function to print numbers from 0 to 5
+     */
+    public void printNumbers() {
+        synchronized(lockObject) {
+            for (int i = 0; i <= 5; i++) {
+                System.out.println(Thread.currentThread().getName() + ": " + i);
+                try {
+                    Thread.sleep(100);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+    }
+}
+
+/**
+ * Thread worker
+ */
+class RunnableWorkerExample3 implements Runnable {
+    PrintUtilExample3 pu3;
+    public  RunnableWorkerExample3(PrintUtilExample3 pu3){
+        this.pu3 = pu3;
+    }
+    @Override
+    public void run() {
+        pu3.printNumbers();
+    }
+}
+
+/**
+ * Main Class
+ */
+public class SynchronizedCustomObjectDemo {
+    public static void main(String[] args) {
+        PrintUtilExample3 pu3 = new PrintUtilExample3();
+        Runnable r = new RunnableWorkerExample3(pu3);
+        Thread t1 = new Thread(r);
+        Thread t2 = new Thread(r);
+        Thread t3 = new Thread(r);
+
+        t1.start();
+        t2.start();
+        t3.start();
+    }
+}

src/SynchronizedMethodDemo.java

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+/**
+ * Utility to print numbers from 0 to 5
+ */
+class PrintUtil {
+    /**
+     * Function to print numbers from 0 to 5
+     */
+    public synchronized void printNumbers() {
+        for (int i = 0; i <= 5; i++) {
+            System.out.println(Thread.currentThread().getName() + ": " + i);
+            try {
+                //simulates delay
+                Thread.sleep(100);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+}
+
+/**
+ * Thread worker
+ */
+class RunnableWorker implements Runnable {
+    PrintUtil pu;
+    public RunnableWorker(PrintUtil pu) {
+        this.pu = pu;
+    }
+
+    @Override
+    public void run() {
+        pu.printNumbers();
+    }
+}
+
+/**
+ * Main Class
+ */
+public class SynchronizedMethodDemo {
+    public static void main(String[] args) {
+        PrintUtil pu = new PrintUtil();
+        Runnable r = new RunnableWorker(pu);
+        Thread t1 = new Thread(r);
+        Thread t2 = new Thread(r);
+        Thread t3 = new Thread(r);
+
+        t1.start();
+        t2.start();
+        t3.start();
+    }
+}

src/SynchronizedStaticMethodDemo.java

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+/**
+ * Utility to print numbers from 0 to 5
+ */
+class PrintUtilExample2 {
+    /**
+     * Function to print numbers form 0 to 5
+     */
+    public static synchronized void printNumbers() {
+        for (int i = 0; i <= 5; i++) {
+            System.out.println(Thread.currentThread().getName() + ": " + i);
+            try {
+                //Sleep is used to simulate delay in thread operations
+                Thread.sleep(100);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+}
+
+/**
+ * Thread worker
+ */
+class RunnableWorkerExample2 implements Runnable {
+    @Override
+    public void run() {
+        PrintUtilExample2.printNumbers();
+    }
+}
+
+/**
+ * Main Class
+ */
+public class SynchronizedStaticMethodDemo {
+    public static void main(String[] args) {
+        Runnable r = new RunnableWorkerExample2();
+        Thread t1 = new Thread(r);
+        Thread t2 = new Thread(r);
+        Thread t3 = new Thread(r);
+
+        t1.start();
+        t2.start();
+        t3.start();
+    }
+}