Update outdated QueryBuilder and Query docs.

Author: greenrobot-team

objectbox-java/src/main/java/io/objectbox/query/Query.java

@@ -38,11 +38,15 @@
 import io.objectbox.relation.ToOne;
 
 /**
- * A repeatable query returning entities.
+ * A repeatable Query returning the latest matching Objects.
+ * <p>
+ * Use {@link #find()} or related methods to fetch the latest results from the BoxStore.
+ * <p>
+ * Use {@link #property(Property)} to only return values or an aggregate of a single Property.
+ * <p>
+ * See the <a href="https://docs.objectbox.io/queries">Queries documentation</a> for details.
  *
- * @param <T> The entity class the query will return results for.
- * @author Markus
- * @see QueryBuilder
+ * @param <T> Entity class for which results are returned.
  */
 @SuppressWarnings({"SameParameterValue", "UnusedReturnValue", "WeakerAccess"})
 public class Query<T> implements Closeable {

objectbox-java/src/main/java/io/objectbox/query/QueryBuilder.java

@@ -27,24 +27,35 @@
 import io.objectbox.Box;
 import io.objectbox.EntityInfo;
 import io.objectbox.Property;
-import io.objectbox.annotation.apihint.Experimental;
 import io.objectbox.annotation.apihint.Internal;
 import io.objectbox.exception.DbException;
 import io.objectbox.relation.RelationInfo;
 
 /**
- * With QueryBuilder you define custom queries returning matching entities. Using the methods of this class you can
- * select (filter) results for specific data (for example #{@link #equal(Property, String)} and
- * {@link #isNull(Property)}) and select an sort order for the resulting list (see {@link #order(Property)} and its
- * overloads).
+ * Builds a {@link Query Query} using conditions which can then be used to return a list of matching Objects.
  * <p>
- * Use {@link #build()} to conclude your query definitions and to get a {@link Query} object, which is used to actually
- * get results.
+ * A simple example:
+ *
+ * <pre>
+ * userBox.query()
+ *     .equal(User_.firstName, "Joe")
+ *     .order(User_.lastName)
+ *     .build()
+ *     .find()
+ * </pre>
+ *
+ * <p>
+ * To add a condition use the appropriate method, for example {@link #equal(Property, String)} or
+ * {@link #isNull(Property)}. To order results use {@link #order(Property)} and its related methods.
+ * <p>
+ * Use {@link #build()} to create a {@link Query} object, which is used to actually get the results.
+ * <p>
+ * Note: by default Query returns full Objects. To return only values or an aggregate value for a single Property,
+ * use {@link Query#property(Property)}.
  * <p>
- * Note: Currently you can only query for complete entities. Returning individual property values or aggregates are
- * currently not available. Keep in mind that ObjectBox is very fast and the overhead to create an entity is very low.
+ * See the <a href="https://docs.objectbox.io/queries">Queries documentation</a> for details.
  *
- * @param <T> Entity class associated with this query builder.
+ * @param <T> Entity class for which the Query is built.
  */
 @SuppressWarnings({"WeakerAccess", "UnusedReturnValue", "unused"})
 public class QueryBuilder<T> implements Closeable {