Writing good unit tests for your central business logic is essential for the speed of your development and a confident deployment to production. But there are also parts of your application where plain unit tests with mocking frameworks like Mockito aren’t that useful or result in a “mocking-hell”. The interaction of your application with your database is…
Manually creating a new Java EE Maven project can be quite cumbersome. Creating all required folders and files for a simple JAX-RS endpoint with a database access was quite error-prone in the past for me. I constantly mixed up WEB-INF and META-INF with its files and was tired of manually creating the project structure. The bootstrapping of a…
Recently Baeldung announced to increase the price of his REST with Spring’s course from $ 249 to $ 299. As I am (or was) a big fan of Baeldung because of his free content about Java & Spring. I purchased the course because I thought I get high-quality and up-to-date content for this amount of money. In…
Recently I had to convert generated .docx files to .pdf files for a more convenient distribution. The Word documents contained some custom formatting and additional pictures. I tried several Java libraries for doing this job (Docx4j, XDocReport and Apache POI) but all of them couldn’t generate the output I got from manually converting the .docx files with Microsoft Word’s native…
Lately, I had the requirement to generate Word documents from specific templates and fill them dynamically with data. For this task, I compared the following Java libraries: Apache POI, iText PDF, Docx4j and XDocreports. I compared them while using the following characteristics: Possibility to replace variables, amount of additional dependencies, lines of code to generate…
Today I want to share a simple approach for up- and downloading files with JavaScript (ES6), React and a Spring Boot backend. This example can be used for any common content type like jpg, pdf, txt, html, png etc. and is not limited to a specific content type. I’ll use the latest version of React (16.4.2…
Recently I had the requirement to limit the access to specific JAX-RS endpoints and to keep track of the user’s current amount of API calls. To solve this problem I asked Adam Bien (@AdamBien) in his monthly Airhacks Q&A about this requirement and he gave me a hint for a possible solution while using the ContainerRequestFilter interface…
For messaging, I have always thought of Apache Kafka as the central solution for messaging. While learning more about Java EE I came along the Java Message Service (JMS) specification and gave it a try. In addition, I wanted to learn more about the JMS capabilities of the Open Liberty application server. In this blog post, I’ll show you how to create a…
Securing your web application can be cumbersome. I recently tried to secure a JSF 2.3 application with the latest Java EE 8 Security API (JSR-375) and it was quite simple. In this blog post, I’ll show you the required configuration steps for securing your JSF application with a form-based authentication mechanism. In the example, I’ll use an…
As my last blog post about a short intro to JavaServer Faces 2.3 got a lot of attention (my tweet got even retweeted by the Java EE Guardian’s twitter page (@javaee_guardian) I want to continue to write about JSF. Today I’ll cover one of the most common use cases for developing web-based applications: displaying/inserting/updating/deleting data…
Scrolling through my news feed on Twitter I get flooded with new releases of npm modules and more and more blog articles about server-side rendering technologies for the latest Single Page Application frameworks like Angular, React. The following tweet summarized my current feelings: As I personally really like React and used it in the past for several projects,…
In today’s post, I want to review the latest technical Java book I read. I came across the book “Java by Comparison” by Simon Harrer, Jörg Lenhard, and Linus Dietz while I was reading Venkat Subramaniam’s blog. Venkat did the foreword of this book and as I am a fan of him, I instantly bought the book….
From July 10th to the 11th I took part in the Hackathon HACK|BAY which was organized by the tech incubator Zollhof in Nuernberg. Even if I participated in several coding challenges and a company internal Hackathon, this was my first Hackathon with a jury and multiple competing teams. The event was sponsored by several local…
In the last weeks, I was searching for a nice solution to send emails to users for one of my side projects. Sending plain text formatted emails with the Spring Boot Mail Starter is quite easy as it is an abstraction using the JavaMailSender interface and auto-configured. It’s also possible to send HTML formatted emails or use…
While I was scrolling through my twitter feed I noticed a post about the new Open Liberty 18.0.0.2 release on June 29. In the official blog post about the new release, they pointed out that Open Liberty now fully supports JavaEE 8 (JAX-RS 2.1, JPA 2.2, JSF 2.3 and so on ..) and that they…