George Georgovassilis writes about technology architecture
What is the right code granularity? I have previously written about reusing functionality [1] in the micro service context and found then that the old aim to optimise code footprint is a metric in need of a good overhaul. Ever since I'm happy that the idea is getting traction: Classes, libraries, applications OOP reuses code … Continue reading Code reusability: from classes to containers
Important note: This post is not being updated. For up-to-date information refer to the project repository: https://github.com/ggeorgovassilis/fauxjsp/ About JSP In this post I'll present a new open source project I'm currently working on, fauxjsp [1] which re-implements JSP in a way that is more robust and faster for developers. It is intended for development, where … Continue reading Fauxjsp: productive JSP development
Abstract Rewritten on 15 January 2015 In this post I'll talk about the problems callbacks introduce into the readability of asynchronous Java programs. I'll also discuss an implementation of method pointers for Java which aids the transformation of a callback-style program into a linear program flow, greatly increasing readability while still being a 100% asynchronous … Continue reading Reactive programming for Java, revisited
Let's say you want to programmatically select a tab with angularjs and bootstrap ui: [CODE MISSING] According to the documentation for 3.1.1 it should be enough to modify the model; here controller.tabUsers or controller.tabGroups. Only: it doesn't work. We'll never know why. The way out is simulating the click with jquery: $("#tab_users a").trigger("click");
TL;DR Hibernate's (3.2-3.4) JPA implementation will pick up hbm files on it's own when it should be looking only at persistence.xml, thus: - loading more entities that it should - loading the wrong entities - performing schema updates in the wrong database This one annoyed me plenty and took a great deal of debugging to … Continue reading LocalContainerEntityManagerFactoryBean, Hibernate and superflous tables created in wrong database
My current project is using JPA, heavily. JPA is a spec/standard/interface and I'm using the Hibernate implementation for it, but I import the entities from a different maven module. The entities module has a dependency on JPA, but not on Hibernate. So when I run my unit tests, I suddenly get a: java.lang.NoClassDefFoundError: org/apache/openjpa/enhance/PersistenceCapable Openjpa? … Continue reading java.lang.NoClassDefFoundError: org/apache/openjpa/enhance/PersistenceCapable
I recently was duped (by myself) at a discussion with a colleague: in our continuous effort to disentangle release schedules of two tightly entangled applications, I exposed some core features as a JSON REST service and told him to "just use the Spring invoker" for JSON. It turns out, there is one for JaxRS, Burlap, … Continue reading An easier to use Java REST client
Time-constrained projects sometimes mandate crude realism as to the type and extent of test coverage in a software project. You'll find arguments for and against testing in the entire spectrum of opinions from "tests are luxury we can't afford" to "regressions are luxury we can't afford". Constrained or not, there is rarely a good excuse … Continue reading Integration testing Spring controllers
JPA, and for that matter Hibernate, depends on identifying entity instances (I'll refer to them as entities for short) by some key. That key can either be a single property (like a numeric ID column in the corresponding table) or a business key (also referred to as natural key). Business keys are entity properties which … Continue reading On JPA identifiers and business keys (or why business keys are a bad idea)
I'm moving a legacy application (I seem to be doing that a lot recently) to Spring and injecting properties with @Value into Spring managed beans all over the place. And it doesn't work: public class SomeService{ @Value("#{the.org.namespace.someProperty}") private String someProperty; } Dots have apparently a special meaning, so this fails with a message that 'the' … Continue reading Spring @Value and resolving property names with dots
