Java: NullPointerException when assigned to null Boolean

Question

When I tried to assign a null Boolean as shown below, I have a NullPointerException.

String strA = "something neither true nor false";
Boolean a = "true".equals(strA) ? true : "false".equals(strA) ? false : null;

I don't know why this happens when other cases like below work.

Boolean a = null;
Boolean a = "true".equals(strA) ? true : null;

+3

Tamajin Apr 27. '15 at 15:00

1 answer

Alex salauyou · Accepted Answer · 2015-04-27T15:05:58+0000

I believe this is a boxing / unboxing issue. Appointment Boolean.TRUE

or Boolean.FALSE

:

Boolean a = "true".equals(strA) 
             ? Boolean.TRUE 
             : ("false".equals(strA) ? Boolean.FALSE : null);

works as expected.