java - Vaadin CheckBox object becomes null -
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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