Java Lambdas and (parallel) Streams

Last month, Geertjan and me talked at JUG Cologne. After he presented new NetBeans features, I talked about Java Lambdas and (parallel) Streams. On the same day, I presented my book about this issue. Unlike my JSF book, I wrote about this matter in German.

If you missed some fresh articles about JSF or NetBeans on this blog, there is a simple reason: During the last weeks, I translated my book into English. And it became ready last weekend.

I’m proud to announce my new book “Java Lambdas and (parallel) Streams”.

title_page_lambdas_mediumIf you like to learn about this matter, you may purchase your copy at

You’ll get this book until Dec. 20th 2015 for an introductory price (33% off) if you use this coupon:



BTW, the operation of this blog costs a lot of money. By buying one of my books, you support me to operate this blog.


Parallel 2015

For the second time, I visited the parallel conference (Parallel2015) [1]. This conference gave a great inside into the state of art of parallel and concurrent programming. Read my report online [2] (Ger). I talked about “Java Lambdas and (parallel) Streams”. You may download my slides from this site [3] (Ger).

To prepare my talk, I created a demo project using NetBeans. Try out its great support for Lambdas and Streams!


[3] LambdasAndStreams


JavaLand 2015 & Java aktuell

Last week I visited JavaLand 2015. This great software conference [1] with lot of community activities resides in my home town Brühl [2].

Beside attending lots of tracks I had the opportunity to meet a couple of people face-to-face like Ed Burns (JSF Spec Lead), Geertjan Wielenga (NetBeans product manager), Arun Gupta (Java EE evangelist) and more, especial lot of JUG members from all over Germany. Read an article about my impressions [3].

Most slides are available for download now [4].

And I had the chance, to attend the celebration of 5 years Java aktuell, the Java magazine by the iJUG [5]. Great!


Conversation Scope

Our next task is to create a new book entry or to edit an existing one. The book editor shall consist of a tab panel offering one page for the books meta data like title, author, publisher, and one page for each language, where you can edit a review. It must be possible to switch between these pages without loosing data. Not very hard to imagine, that we need a backing bean living longer than just one request. Continue reading “Conversation Scope”

Web Development with Java and JSF: Bean Validation

As stated before, Books is an application, maintained by just one author, who should know about the expected data. Thus, there is no user interface with immediate response after each input or lots of hints. Of course, those features are essential for an application for potentially “unknown” users. Later on, when developing Alumni, we will cover those features in detail. However, a validation is useful to prevent the user from entering data which might not fit the database. Continue reading “Web Development with Java and JSF: Bean Validation”