java - Null Pointer Exception for Ebean Insert Query -

i have e bean model of table countries , indicators. indicators model looks this

public class indicators extends model {  private static final long serialversionuid = 1l;  @id public long id;  @onetomany(mappedby = "indicator") public hashset<indicators> transactions;  @manytoone @joincolumn(name = "countryid") public countries country; } 

and countries model looks this

    public class countries extends model {           private static final long serialversionuid = 1l;             @id           @column(name = "countryid")           public long countryid;            @onetomany(mappedby = "country")           public hashset<countries> indicators;              } 

and trying call insert function

  private static void procm007_sp003(excelind excelrow, string indicator_code) {      // insert     indicators indobj = new indicators();     indobj.country.countryid=542l;             indobj.save(); 

however, indobj.country.countryid causes null pointer exception.

any appreciated. :)

by default instance variables set null , have not initialized country variable of object indicators, null. , hence setting countryid on null object lead nullpointerexception.

you need initialize country attribute of indicators object also:

indicators indobj = new indicators(); indobj.country = new countries(); indobj.country.countryid = 542l; indobj.save();