Building a Filter in a loop, JSONPath -

i want loop through array of strings , add each string jsonpath filter object:

filter f = filter(); // error (int j = 0; j < in_paths.size(); j++)  {       f = f.and(where(in_paths[j]).exists(true)); } 

the problem approach can't seem create "empty" filter. know if possible? if not, can offer alternative?

the initial filter can check see if document root exists.

filter f = filter(where("$").exists(true)); (int j = 0; j < in_paths.size(); j++)  {       f = f.and(where(in_paths[j]).exists(true)); }