Boxing unboxing

Boxing
int a = 44335;
Integer b = Integer.valueOf(a);
Integer c = a; // automatic boxing

Unboxing
Integer c = 566;
int y = c.intValue();
int z = c; // automatic unboxing

Integer обертка для int

Java caches the integer objects in the range -128 to 127

Integer i = 126;
Integer i2 = 126;

Integer i3 = 128;
Integer i4 = 128;

System.out.println(i == i2); // true, reference pointing to same literal
System.out.println(i3 == i4); // false, reference pointing to different objects

Integer i = new Integer(126);
Integer i2 = new Integer(126);

System.out.println(i == i2); // false