java - Jackson - serializing a list containing null elements -

i'm using jackson 2.4 serialize objects json.
when serialize list of objects, having elements null, result json string contains "null" strings.

how prevent "null" elements being serialized? there configuration objectmapper? have set "setserializationinclusion(include.non_null)"!

here code :

list<string> strings = new arraylist<>(); strings.add("string 1"); strings.add("string 2"); strings.add(null); strings.add(null); 

after serializing got :

[string 1, string 2, null, null] 

how json string without "null"?

[string 1, string 2] 

using @jsoninclude annotation.

@jsoninclude(include.non_null) class foo {   string bar;  } 

edit

also can create own serializer.
example :

public static void main(string[] args) throws jsonprocessingexception {          list<string> strings = new arraylist<>();         strings.add("string 1");         strings.add("string 2");         strings.add(null);         strings.add(null);          objectmapper mapper=new objectmapper();         mapper.getserializerprovider().setnullvalueserializer(new nullserializer());         system.out.println(mapper.writevalueasstring(strings));     } 

nullserializer.java

class nullserializer extends jsonserializer<object> {   @override   public void serialize(object obj, jsongenerator jsongen, serializerprovider unused)        throws ioexception, jsonprocessingexception   {     jsongen.writefieldname("");   } } 

will print

["string 1","string 2","",""] 

then can remove jsongen.writefieldname(""); print

["string 1","string 2"]