Java开关案例声明问题

Question

I'm trying to use a switch statement in Android aplication,where I have to check if an integer is equal to some of the Enum's value.The code goes like this :

    public enum RPCServerResponseCode{


        E_INCORRECT_LOGIN(4001),                
        E_ACCOUNT_DISABLED(4002),
        E_ACCOUNT_NOT_ACTIVE(4003);


        private int value;
        private RPCServerResponseCode(int i) {
            this.value=i;
        }
        public static RPCServerResponseCode getByValue(int i) {
             for(RPCServerResponseCode dt : RPCServerResponseCode.values()) {
                 if(dt.value == i) {
                     return dt;
                 }
             }
             throw new IllegalArgumentException("No datatype with " + i + " exists");
         }

    }

}

And my switch statement looks like this :

int errorCode;
switch(errorCode){

            case  RPCServerResponseCode.E_INCORRECT_LOGIN :
            {
                    if (user.isAuthenticated)
                    {
                        // logout before login
                    }
                    break;
            }
            case RPCServerResponseCode.E_ACCOUNT_NOT_ACTIVE:  
            {
                if (user.isAuthenticated)
                {
                    //logout
                }
                break;
            }
        }

    }

But I get error saying this : "Type mismatch: cannot convert from RPCCommucatorDefines.RPCServerResponseCode to int". Any suggestions how to solce that issue? Thanks in advance!!!

Answer 1

errorcode is int . Should be of type RPCServerResponseCode , so you could use something like:

switch (RCPServerResponseCode.getByValue(errorcode))
{
    ...
}

Answer 2

You're trying to compare your INT error code to a RPCServerResponseCode instance - This isn't possible. You need to use the method getByValue in your RPCServerResponseCode class to do the conversion for you. After that, you can use the result (Which will be a RPCServerResponseCode instance) in your switch statement:

int errorCode;
RPCServerResponseCode responseCode = RPCServerResponseCode.getByValue(errorCode);

switch(responseCode){

            case  RPCServerResponseCode.E_INCORRECT_LOGIN :
            {
                    if (user.isAuthenticated)
                    {
                        // logout before login
                    }
                    break;
            }
            case RPCServerResponseCode.E_ACCOUNT_NOT_ACTIVE:  
            {
                if (user.isAuthenticated)
                {
                    //logout
                }
                break;
            }
        }

    }

Answer 3

Java enums are fully-fledged objects and cannot be implicitly cast to integers.

This should work:

switch(RPCServerResponseCode.getByValue(errorCode)){

Answer 4

you can say

int errorCode=4001;
RPCServerResponseCode code = RPCServerResponseCode.getByValue(errorCode);
switch(code){
...
}