can we give @QueryParam of type boolean a default value null?

Question

can we give @QueryParam of type boolean a default value null? if yes, how do we do it?

this is how I tried to do it but I still get false as default value:

@POST
public String setMethod(
        @QueryParam("value1") @DefaultValue("null") Boolean value1)

Answer 1

You should try without DefaultValue . As value1 is not a primitive it should stay null .

So like this:

@POST
public String setMethod(
        @QueryParam("value1") Boolean value1)

following the spec:

If @DefaultValue is not used in conjunction with @QueryParam, and the query parameter is not present in the request, the value will be an empty collection for List, Set, or SortedSet; null for other object types; and the default for primitive types.

Regarding your example --> new Boolean("null") is actually equals to false .

So the result is normal.

BTW : Null should not be a valid option as a Boolean is a binary value either 0 or 1. Once it crosses into the tri-state (null, false, true) it's no longer a true Boolean and maybe if it is acceptable preferable to switch to enum value.

What about something like this?

public enum Value {
    A ,
    B,
    ABSENT
}

@POST
public String setMethod(
        @QueryParam("value1") @DefaultValue("ABSENT") Value value1)