Integer的比较

public static void main(String[] args) {
    Integer i1 = 127;
    Integer i2 = Integer.valueOf(127); // integercache
    Integer i3 = new Integer(127);
    System.out.println(i1 == i2); // true
    System.out.println(i1 == i3); // false
    System.out.println(i2 == i3); // false
    System.out.println(i2.equals(i3)); // true
    Integer i4 = 200;
    Integer i5 = Integer.valueOf(200);
    Integer i6 = new Integer(200);
    System.out.println(i4 == i5);// false
    System.out.println(i4 == i6);// false
    System.out.println(i5 == i6);// false
    System.out.println(i5.equals(i6)); // true

}