Use ResultQuery.collect() to Implement Powerful Mappings

In our opinion, any Iterable<T> should offer a <R> collect(Collector<T, ?, R>) method to allow for transforming the the content to something else using standard JDK collectors, jOOλ collectors from org.jooq.lambda.Agg or your own. When using jOOQ, you don't have to wait for the JDK to finally add these useful utilities to the Iterable API. … Continue reading Use ResultQuery.collect() to Implement Powerful Mappings

Lesser Known jOOλ Features: Useful Collectors

jOOλ is our second most popular library. It implements a set of useful extensions to the JDK's Stream API, which are useful especially when streams are sequential only, which according to our assumptions is how most people use streams in Java. Such extensions include: // (1, 2, 3, 1, 2, 3, 1, 2, 3, 1, … Continue reading Lesser Known jOOλ Features: Useful Collectors

Using jOOλ to Combine Several Java 8 Collectors into One

With Java 8 being mainstream now, people start using Streams for everything, even in cases where that's a bit exaggerated (a.k.a. completely nuts, if you were expecting a hyperbole here). For instance, take mykong's article here, showing how to collect a Map's entry set stream into a list of keys and a list of values: … Continue reading Using jOOλ to Combine Several Java 8 Collectors into One

2016 Will be the Year Remembered as When Java Finally Had Window Functions!

You heard right. Up until now, the awesome window functions were a feature uniquely reserved to SQL. Even sophisticated functional programming languages still seem to lack this beautiful functionality (correct me if I'm wrong, Haskell folks). We've written tons of blog posts about window functions, evangelising them to our audience, in articles like: Probably the … Continue reading 2016 Will be the Year Remembered as When Java Finally Had Window Functions!

How to Translate SQL GROUP BY and Aggregations to Java 8

I couldn't resist. I have read this question by Hugo Prudente on Stack Overflow. And I knew there had to be a better way than what the JDK has to offer. The question reads: I'm looking for a lambda to refine the data already retrieved. I have a raw resultset, if the user do not … Continue reading How to Translate SQL GROUP BY and Aggregations to Java 8

Java 8 Friday: No More Need for ORMs

At Data Geekery, we love Java. And as we're really into jOOQ's fluent API and query DSL, we're absolutely thrilled about what Java 8 will bring to our ecosystem. Java 8 Friday Every Friday, we're showing you a couple of nice new tutorial-style Java 8 features, which take advantage of lambda expressions, extension methods, and … Continue reading Java 8 Friday: No More Need for ORMs