Why doesn't String switch statement support a null case?

Question

I am just wondering why the Java 7 switch statement does not support a null case and instead throws NullPointerException? See the comm

Answer 1

It isn't pretty, but String.valueOf() allows you to use a null String in a switch. If it finds null, it converts it to "null", otherwise it just returns the same String you passed it. If you don't handle "null" explicitly, then it will go to default. The only caveat is that there is no way of distinguishing between the String "null" and an actual null variable.

    String month = null;
    switch (String.valueOf(month)) {
        case "january":
            monthNumber = 1;
            break;
        case "february":
            monthNumber = 2;
            break;
        case "march":
            monthNumber = 3;
            break;
        case "null":
            monthNumber = -1;
            break;
        default: 
            monthNumber = 0;
            break;
    }
    return monthNumber;