java - Vaadin CheckBox object becomes null -

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i have vaadin object:

checkbox mycb = new checkbox("caption");

later on value of checkbox updated database this:

mycb.setvalue(dbvalue);

dbvalue null in database. mycb not null before line, , null after line. shouldn't value remain same, mycb.getvalue() returning null?

furthermore, trying avoid nullpointerexception short-circuit evaluation:

if (mycb != null && mycb.getvalue() == true)  ...

that produces nullpointerexception anyway. normal behavior or there i'm doing wrong?

you said mycb doesn't become null. that's great.

if (mycb != null && mycb.getvalue() == true)

this throws nullpointerexception because java tries cast result of mycb.getvalue() boolean. because mycb.getvalue() returns null, throws nullpointerexception.

change to:

if (mycb.getvalue() != null && mycb.getvalue() == true)

or similar


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