Time to meet Java 8 with Lambda Expressions!

The Java 8 development is on its way an the (nearly) feature complete JDK 8 M6 (build b75) release was published on 2013/01/31. This version contains the Lambda Expressions - so time to meet!

The JDK 8 M6 is available on the JDK 8 project site. The installation process is simple and (as far as I noticed) does not contain any Ask toolbar installation option ;-) After the installation my system featured the following java version:

C:\>java -version
java version "1.8.0-ea"
Java(TM) SE Runtime Environment (build 1.8.0-ea-b75)
Java HotSpot(TM) 64-Bit Server VM (build 25.0-b17, mixed mode)

The Project Lambda provides a Netbeans 8 Nightly Build with experimental Lambda support but as my first example is trivial I just ignored the IDE compiler warnings and compiled and ran the class from the command line.

And that's it. Comparator implementation with Lambda Expressions:

	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.Collections;
	import java.util.List;
	public class LambdaCompare {
	public static void main(String[] args) {
	// sort ascending
	List<Integer> listAsc = new ArrayList<>();
	listAsc.add(3);
	listAsc.add(1);
	listAsc.add(2);
	Collections.sort(listAsc, (Integer o1, Integer o2) -> { return o1.compareTo(o2); });
	System.out.println(Arrays.toString(listAsc.toArray()));
	// sort descending
	List<Integer> listDesc = new ArrayList<>();
	listDesc.add(3);
	listDesc.add(1);
	listDesc.add(2);
	Collections.sort(listDesc, (Integer o1, Integer o2) -> { return o2.compareTo(o1); });
	System.out.println(Arrays.toString(listDesc.toArray()));
	}
	}

view raw LambdaCompare.java hosted with ❤ by GitHub

As hoped (and expected) the output is:

[1, 2, 3]
[3, 2, 1]

 No big deal but I am glad it worked! Now I am ready to move on...

Some links:

• OpenJDK
• JDK 8 project
• Project Lambda
• State of the Lambda by Brian Goetz
• Java 8 blog posts by +Christian Ullenboom (german)

Update: It turned out that the JDK M6 build is not feature complete yet. The current status is explained by Mark Reinhold here