java - Getting data from JTable to jText fields, but i'm getting Null Pointer Exception -


this question has answer here:

i'm trying values jtable (the values in jtable mysql) jtextfield.

i got "null pointer exception" after selecting row.

after put line breakpoint see row number get. @ rs=ppst.executequery(); line shows me nullpointerexception.

what's wrong?

here code:

private void jtablestudentaimouseclicked(java.awt.event.mouseevent evt) {                                                      try{             int row = jtablestudentai.getselectedrow();             string table_click = (jtablestudentai.getmodel().getvalueat(row, 0).tostring());              string sql = "select * studentas inner join grupė on studentas.grupėsid=grupė.grupėsid studentonr ='"+table_click+"'";        ppst=co.preparestatement(sql);        rs=ppst.executequery();        if(rs.next()){         string add0 = rs.getstring("studentonr");        jtextfield1.settext(add0);        string add1 = rs.getstring("vardas");        jtextfieldvardas.settext(add1);        string add2 = rs.getstring("pavardė");        jtextfieldpavarde.settext(add2);        string add3 = rs.getstring("epaštas");        jtextfieldpastas.settext(add3);        }         }catch(exception e){             joptionpane.showmessagedialog(null, e);         }`

well, if preparestatement(sql) unable produce prepared statement, might have returned null; that's easy check breakpoint, , maybe looking stacktrace. have no space between "student" , "as" in sql posted, looks potential problem...


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