Class AutoboxingExamples

java.lang.Object

net.jrodolfo.java_evolution.java05.AutoboxingExamples

public class AutoboxingExamples
extends Object

Demonstrates autoboxing and unboxing, introduced in Java 5.

Constructor Summary

Constructors

Constructor	Description
AutoboxingExamples()

Method Summary

Modifier and Type	Method	Description
List<Integer>	boxedNumbers(int left, int right)	Adds primitive int values to a list of Integer values.
int	sumBoxedNumbers(List<Integer> numbers)	Adds boxed values as primitive int values.
int	unbox(Integer number)	Shows the important caveat: unboxing null is still a NullPointerException.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

AutoboxingExamples

public AutoboxingExamples()

Method Details

boxedNumbers

public List<Integer> boxedNumbers(int left,
 int right)

Adds primitive int values to a list of Integer values. The compiler boxes each primitive for the collection.

Parameters:

left - first value

right - second value

Returns:

boxed integers in insertion order

sumBoxedNumbers

public int sumBoxedNumbers(List<Integer> numbers)

Adds boxed values as primitive int values. The compiler unboxes each Integer before arithmetic.

Parameters:

numbers - boxed numbers

Returns:

the primitive sum

unbox

public int unbox(Integer number)

Shows the important caveat: unboxing null is still a NullPointerException.

Parameters:

number - boxed number

Returns:

primitive value