I am trying translate this Python code to Java from the presentation Building Scalable,

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Asked: June 1, 20262026-06-01T16:34:54+00:00 2026-06-01T16:34:54+00:00

I am trying translate this Python code to Java from the presentation Building Scalable,

0

I am trying translate this Python code to Java from the presentation
Building Scalable, Complex Apps on App Engine,

Is there support on GAEJ to do this?

indexes = db.GqlQuery( "SELECT __key__ FROM MessageIndex " "WHERE receivers = :1", me)
keys = [k.parent() for k in indexes] 
messages = db.get(keys)

Below my implementation in Java. Are these functional and performance wise equivalent? What happens if i have large number of keys?

Query query1 = new Query("MessageIndex");
query1.setKeysOnly();
query1.addFilter("receivers", FilterOperator.EQUAL, me);

PreparedQuery pq2 = datastore.prepare(query1);

Iterable<Entity> entities = pq2.asIterable();
HashSet<Key> keys = new HashSet<Key>();
    for (Entity en : entities)
       keys.add(en.getParent());

Query query2 = new Query("Messages");
query2.addFilter("__key__", FilterOperator.IN, keys);