See SBQL4J. It's type-safe strong query language integrated with Java. Allows to write complicated and multiply nested queries. There is a lot of operators, Java methods can be invoked inside queries so as constructors. Queries are translated to pure Java code (there is no reflection at runtime) so execution is very fast.
EDIT: Well, so far SBQL4J it's the ONLY extension to Java language which gives query capabilities similar to LINQ. There are some interesting project like Quaere and JaQue but they are only API's, not syntax / semantics extension with strong type safety in compile time.
Java LINQ to SQL implementation. Provides full language integration and larger feature set compared to .NET LINQ.
There is no such feature in java. By using the other API you will get this feature. Like suppose we have a animal Object containing name and id. We have list object having animal objects. Now if we want to get the all the animal name which contains 'o' from list object. we can write the following query
from(animals).where("getName", contains("o")).all();
Above Query statement will list of the animals which contains 'o' alphabet in their name. More information please go through following blog. http://javaworldwide.blogspot.in/2012/09/linq-in-java.html
An anonymous user mentioned another one, Diting:
Diting is a class library provides query capabilities on collections through chainable methods and anonymous interface like Linq in .NET. Unlike most of other collection library those are using static methods need iterate whole collection, Diting provides a core Enumerable class whitch contains deffered chainable methods to implement query on collection or array.
Supported Methods: any, cast, contact, contains, count, distinct, elementAt, except, first, firstOrDefault, groupBy, interset, join, last, lastOrDefault, ofType, orderBy, orderByDescending, reverse, select, selectMany, single, singleOrDefault, skip, skipWhile, take, takeWhile, toArray, toArrayList, union, where