Consider the following piece of Java code.
public static void main(String args)
Integer intWrapper = new Integer(100);
System.out.println("intWrapper = " + intWrapper);
In this example, the Integer Wrapper object is created with integer value set as 100;
The Wrapper Object is incremented as intWrapper++ and its value changed to 101. Here, Java is taking care of un-boxing, increment the value and then re-assign the incremented value to the Integer Wrapper Object. This is called Auto Boxing.
This is introduced in Java 5.