Using Integer type in Switch statement in java

Question

I wrote simple code in java for my Android application and got these errors.

case expressions must be constant expressionswhile private static final Integerconstant

private static final Integer INVALID_USER = 901;
private static final Integer SENDING_FAILED = 902;
private static final  Integer OK = 903;
/*
 *
 *  And some more project related declaration...
 *
 */


        switch (responseCode){
            case INVALID_USER:

                    // logout
                    break;

            case SENDING_FAILED:

                    //resend request
                    break;

            case OK:
                    break;
        }

This is because I used Integer Type, then I changed the type to intand the problem is solved

My question is why we cannot use Integercase as an expression. The docs say, “The switch works with byte, short, char, and int primitive data types. It also works with enumerated types (discussed in Enum types), the String class, and several special classes that wrap some primitive types: Character, Byte, Short, and Integer " , although the variable is constant. I read this question , but received nothing.

Answer 1

case switch ( §14.11) ( §5.2) .....

Definition of Constant Expression §15.28

, , .

, . Integer Expression .

Answer 2

"" : " , , char int . ( Enum), String , : , , "

switch(expressions used here)

case.

int case, Integer.valueOf(your_int_value);, Integer

Answer 3

java Object . byte, int, char . jdk1.7 String switch. Wraper Class valueOf -

private static final Integer INVALID_USER = 901;
private static final Integer SENDING_FAILED = 902;
private static final  Integer OK = 903;
/*
 *
 *  And some more project related declaration...
 *
 */


        switch (responseCode){
            case INVALID_USER.valueOf():

                    // logout
                    break;

            case SENDING_FAILED.valueOf():

                    //resend request
                    break;

            case OK.valueOf():
                    break;
        }