Paul Sterl has written 57 articles

Serialization Jackson vs Google Protocol Buffers

Where are many articles around comparing the serialization between different frameworks and of course different encodings. I came around recently the problem that I needed a very fast serialization for pretty simple objects but between different platforms (embedded device with C, Android Java, iOS Objective-C and Java Backend). Well first reaction, let us just take…

JavaScript Module Pattern or Just Private Variables

JavaScript is a wonderful language to get thinks fundamentally wrong from the start. As so where are many patters around to help us to avoid some of these challenges ;-). The module pattern is one of the most known and used. It helps us to create private variables or better to avoid side effects in…

Use Session and Request Scope Beans in Tests with Spring

Sometimes it is useful haven the Web Scopes in Unit Tests. Usually Spring just show this very useful error in the Unit Test: Caused by: java.lang.IllegalStateException: No Scope registered for scope ’session‘ at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:334) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194) at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1120) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1044) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:942) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:533) … 28 common frames omitted You can easily have all needed…

Spring Boot Configuration – Properties not loaded

I had recently a very interesting problem using Spring Boot and the automagic concerning the configuration. The Problem org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‚demo.MyApplicationTests‘: Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private java.lang.String demo.MyApplicationTests.url; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder ‚my.url‘ in string value „${my.url}“ at…

Strong IDs

In some projects you may encounter the so called „strong id pattern“. What is it? Strong IDs are simply wrapped primitive or simple types into classes. Just remember what we did in Java before the Enum come around. We had just Strings or Numbers in the code which we used to assign well known values…

JSR 303 Validation for Dates

A common case is to validate date inputs in Java e.g. to avoid the nice and friendly typos like 06/01/1500. Nevertheless by default where is not to much support to handle this very common case. So let’s fix this together: Annotation first The first we need is a JSR annotation which we use to annotate…