Tuesday Jul 16, 2013

Videos: Getting started with jtreg

jtreg is the test harness used by the OpenJDK test framework. This framework is intended primarily for regression tests. It can also be used for unit tests, functional tests, and even simple product tests -- in other words, just about any type of test except a conformance test, which belong in a TCK. jtreg currently supports over 10,000 tests that have been written for the JDK. 

Balchandra Vaidya, technical staff member at Oracle, gave a jtreg tutorial at a TestFest hosted by the London Java Community. The presentation was broken into four sections and all are now available on the Oracle Java YouTube channel. Part 1 is called Getting started with JTREG, it includes an introduction on using jtreg. The nuts and bolts of a jtreg test case, how to execute a jtreg test case, an example of a test case and a review of the log file produced. A demo of the example is also included and finally some links to reference materials. 

Parts 2, 3, and 4 are available on the YouTube/Java channel.

Thursday Mar 07, 2013

OpenJDK Test Fest and Devoxx UK

The London Java user group is organizing the first Test Fest on March 23rd in London with the collaboration of Oracle and IBM. "Contributors to OpenJDK need to be confident that their changes are sound and do not cause problems elsewhere." explains event host Martijn Verburg. Many test cases are already available but each application has different characteristics, environment and other attributes. The goal is to provide a larger and more comprehensive series of tests for Open JDK. 

If you cannot attend this event, the organizers and some of the guest presenters from Oracle and IBM - among them Oracle engineer Stuart Marks - will be at Devoxx UK starting Monday evening until Thursday (from March 25th until the 27th). Stuart Marks will present a Bird-of-a-Feather (BoF) session about "the testing of OpenJDK" on Tuesday, March 26th at 8:00pm and Martijn Verburg will talk about OpenJDK Hack Session Tuesday evening at 8:00pm and 9:00pm. Don't forget to register for Devoxx UK!

Additional online resources: Collaborate with the OpenJDK Quality team Online information FAQ


Thursday Jan 24, 2013

Coding on Crete with Java Specialist Heinz Kabutz

In a new article, now up on otn/java by yours truly, titled “Coding on Crete: An Interview with Java Specialist Heinz Kabutz,” noted Java commentator and consultant Dr. Heinz Kabutz shares insights about the Java platform and talks about his exotic life working as a developer on the island of Crete. Kabutz is well known as the author of the Java Specialists’ Newsletter which reaches some 70,000 developers worldwide.

In a previous 2007 interview, Kabutz lamented the large number of developers who do not engage in unit testing. He offered an update on this:

“The one place where unit testing is sorely lacking is with concurrent code. There are some tools that help find race conditions and deadlocks, but they typically find about a dozen faults per line of code. With such an amount of false positives, discovering a real problem is impossible.

Did you know that there is not a single—not even one—unit test for the Java Memory Model (JMM)? We have to just accept that it works on the Java Virtual Machine (JVM) we are running on. The theory is that if we write our Java code according to the JMM, the code will run correctly on any certified JVM. Unfortunately, the certification does not test the JMM thoroughly. Apparently, there are some tests for the java.util.concurrent classes, and so they assume that if these work, then the JMM must also be correct for that JVM.”

When asked about the greatest performance issues he remarked:

“The biggest performance issue today is still that we often cannot pinpoint the bottlenecks. Customers usually approach us with problems that they have not been able to solve, no matter how many man-months they've thrown at them. The most recent issue I looked at boiled down to a simple race condition. If two threads insert an entry into a shared HashMap at the same time, and the key's hash code points to the same entry in the table, then the HashMap can be corrupted and you might get two entries pointing to each other. This means that whenever you try to call contains() on the map, you risk getting an infinite loop.”

Check out the article.

Wednesday Jun 13, 2012

The Enterprise Side of JavaFX - Part One

A new article, now up on otn/java, by Java Champion Adam Bien, titled “The Enterprise Side of JavaFX,” shows developers how to use LightView to convert REST services into a bindable set of properties. The article, Part One of a three-part series, presents the enterprise and business side of JavaFX with minimal animations, effects, and transitions, and a focus on structuring the presentation logic and integration with back-end services.

Bien makes use of LightFish, LightView and much more:

“LightFish is an open source monitoring application that periodically fetches and persists snapshots from a “GlassFish Under Test” machine and makes them available in real time via a simplified REST API.

LightFish comes with a basic Web interface to manage the data-capturing interval that is implemented with JavaServer Faces 2. LightView is a JavaFX 2 real-time visualizer that integrates the Web UI directly and accesses the monitoring data via REST and long polling. It could be considered to be a ‘stress test dashboard.’”

Look for Part Two of the series, which will directly integrate the JavaServer Faces 2 UI with WebView.

Check out the article here.

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