GAE- Generate Child Entity key

Here the simple way to make.

ParentEntity.getKey().getChild(ChildKind, keyname);

GAE- The method addFilter(String, Query.FilterOperator, Object) from the type Query is deprecated

In this situation, we can fixed this by changing out code.

Import the Libraries

import com.google.appengine.api.datastore.Query;
import com.google.appengine.api.datastore.Query.CompositeFilterOperator;
import com.google.appengine.api.datastore.Query.FilterOperator;

Sample:

Query query = new Query(Kind);
query.addFilter("active", FilterOperator.EQUAL, 1l);
query.addFilter("user", FilterOperator.EQUAL, _user);

Solution1:

Filter activeFilter =
  new FilterPredicate("active",FilterOperator.EQUAL,1l);
Filter userFilter =
  new FilterPredicate("user",FilterOperator.EQUAL,_user);

// Combine the Two filter
Filter queryFilter =
  CompositeFilterOperator.and(activeFilter, userFilter);

// Use class Query to assemble a query
Query q = new Query("Person").setFilter(queryFilter);

Solution 2

query = new Query(Kind);
query.setFilter(CompositeFilterOperator.and(
  FilterOperator.EQUAL.of("active", 1l),
  FilterOperator.EQUAL.of("user", _user)
  )
);

If you want look more info you cant find Datastore Queries and GAE Query

Happy Reading