What is the Java equivalent for LINQ? [closed]

Answer 1

You won't find an equivalent of LINQ unless you use the javacc to create your own equivalent.

Until that day when someone finds a viable way to do so, there are some good alternatives, such as

• jOOQ
• JINQ
• JaQue
• JaQu
• Linq4j
• Quaere (No longer maintained)
• QueryDSL
• JSR-341

Answer 2

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

Answer 3

Maybe not the answer you're hoping for, but if some part of you code need heavy work on collections (searching, sorting, filtering, transformations, analysis) you may take in consideration to write some classes in Clojure or Scala.

Because of their functional nature, working with collections is what they're best at. I don't have much experience with Scala, but with Clojure you'd probably find a more powerful Linq at your fingertips and once compiled, the classes you'd produce would integrate seamlessy with the rest of the code base.

Answer 4

Just to add another alternative: Java 6 does have a solution for type-safe database queries using the javax.persistence.criteria package.

Though i must say that this is not really LINQ, because with LINQ you can query any IEnumerable.

Answer 5

For basic functional collections, Java 8 has it built in, most of the major non-Java JVM languages have it built in (Scala, Clojure, etc), and you can get add on libs for earlier Java versions.

For full language integrated access to a SQL database, Scala (runs on the JVM) has Slick

Answer 6

Check out tiny-q. (Note that you currently can't download it.)

Here's an example adapted the above link:

First we need a collection of some data, let's say a set of strings

String[] strings = { "bla", "mla", "bura", "bala", "mura", "buma" };

Now we want to select only the strings which start with "b":

Query<String> stringsStartingWithB = new Query<String>(strings).where(
    new Query.Func<String, Boolean>(){
        public Boolean run(String in) {
            return in.startsWith("b");
        }
    }
);

No actual data moved copied or anything like that, it will get processed as soon as you start iterating:

for(String string : stringsStartingWithB ) {
    System.out.println(string);
}