Now that Java 8 supports lambdas, it's possible to create Java APIs that closely resemble LINQ.
Jinq is one of these new LINQ-style libraries for Java.
I am the developer of this library. It is based on five years of research on using bytecode analysis to translate Java to database queries. Similar to how C#'s D-LINQ is a query layer that sits on top of the Entity Framework, Jinq is able to act as a query layer sitting on top of JPA or jOOQ. It has support for aggregation, groups, and subqueries. Even Erik Meijer (the creator of LINQ) has acknowledged Jinq.
