Integer i = ...

switch (i){

case null:

doSomething0();

break;

}

In the code above I cant use null in switch case statement. How can I do this differently?

I can't use default because then I want to do something else.

解决方案

This is not possible with a switch statement in Java. Check for null before the switch:

if (i == null) {

doSomething0();

} else {

switch (i) {

case 1:

// ...

break;

}

}

You can't use arbitrary objects in switch statements*. The reason that the compiler doesn't complain about switch (i) where i is an Integer is because Java auto-unboxes the Integer to an int. As assylias already said, the unboxing will throw a NullPointerException when i is null.

* Since Java 7 you can use String in switch statements.

More about switch (including example with null variable) in Oracle Docs - Switch