Java Foundation version 1.5 new features auto boxing unboxing Date SimpleDateFormat calendar.getinstance () get a Calendar object abstract do not generate object get set add System.arraycopy () For expansion of collections, etc.

8 wrapper classes for 8 basic data types

BYTE byte

Short Short

int Integer

Long Long

float float

Double Double

Char Character

Boolean Boolean

Integer a=127; Integer b= 127; // The virtual machine is automatically boxed when the special processing, -127~128 the following automatically take the

System.out.println (a==b); result is true

If it is an integer a=128; Integer b=128;

System.out.println (a==b); The result is false

System.out.println (a.equals (b)); The comparison is the content, because the replication over equals result is true

Java Foundation version 1.5 new features auto boxing unboxing Date SimpleDateFormat calendar.getinstance () get a Calendar object abstract do not generate object get set add System.arraycopy () For expansion of collections, etc.