Problem

Create two threads - one that prints odd numbers till 10 in the format "Odd 1", "Odd 3" etc. and one that prints even numbers till 10 in the format "Even 0", "Even 2" etc..

Need to implement coordination between them so that the output will be:

Even0

Odd1

Even2

Odd3

Even4

Odd5

Even6

Odd7

Even8

Odd9

Even10

Java.lang.Object provides three methods – notify(), notifyAll() and wait () – to improve the efficiency communication between threads. You will need to understand the synchronization process in Java to understand the communication using wait, notify and notifyAll.

• obj.wait()

  • makes a thread wait on an object (obj) until it receives a notification from a notify() or notifyAll() on the same object.

You can create threads directly instantiating a Thread class or using the newer better and safer concurrency package features such as Executors.

Though it is not preferred to create threads directly in new code, learning to create threads directly working with Thread class helps to understand basics well.

We can create a Thread by

• extending the Thread class or

• implementing Runnable interface and passing it to a Thread class constructor.

A daemon thread is a background thread and dies when the thread that created it ends.

A thread that is not daemon is called a user thread.

We can make a thread as daemon thread by calling setDaemon (true) on the thread instance.

We can call setDaemon() for a thread only before it starts, else an IllegalThreadStateException will be thrown.

Example:

MyThread t1= new MyThread ();

t1.setDaemon(true);

t1.start(); 

Java supports both SOAP-based and REST-style web services.

JAX-WS

• Java API for XML Web services (JAX-WS) can be used for SOAP-based as well as REST-style, but more suited for SOAP.

  • The current version of JAVA–WS is 2.x and previous version was called JAX RPC 1.x.

  • JAX–WS is commonly shortened to JWS for Java Web Services.