Author Archives: Dániel Hári

About Dániel Hári

Dániel Hári is the founder of, Who is an enthusiastic Java developer who enhances his knowledge by continously searching for best practices and modern technologies. Engaged to clean coding, and honors the engineering profession as releasing quality work.

Why CheckStyle ruins down code quality…?


What??? CheckStyle is to guarantee code quality, or not? No, it can not, but can make huge damage in quality if used in a wrong way. I try to make this clear. The only purpose of Code quality could be to make the developers life easier. The compiler doesn’t care if you made comments for all your getter-setter. The consumer… Read more »

A pipeline chain – Process async values like Java 8 Streams

What is pipeline? Pipeline is an implementation of a chain of nodes for processing values asynchronously, that can be configured in an elegant way by fluent interface. Similar to java 8 stream api, but with stream api you must have your values in advance (in a collection). So if you don’t have them (eg.: you receive values from user input),… Read more »

Uncle Bob – Payroll Case Study (A full implementation)

This is my implementation of Robert C. Martin’s Payroll-Case-Study learning project presented in his book Agile Software Development, and in his videos on The clean Architecture The clean architecture separates concerns of the application in a scalable and maintainable way. Clean architecture systems are: Independent of Frameworks. The architecture does not depend on the existence of some library of… Read more »

GWT + Guice servlet Example

This downloadable maven project integrates GWT with Guice while you can define web scoped components by annotations. Guice Servlet provides a complete story for use in web applications and servlet containers. Guice’s servlet extensions allow you to completely eliminate web.xml from your servlet application and take advantage of type-safe, idiomatic Java configuration of your servlet and filter components. This example… Read more »

Guice-repository simple example

If you like Spring DATA-JPA’s repository pattern, but you want to use it in a guice project, there is a library for that called guice-repository. The only drawback of using this library is that it pulls almost the entire spring framework as a dependency since it uses it’s classes. This simple example project has: Dependency Injection through Guice(@Inject), JPA Repositories(Spring’s… Read more »

Auto compile SASS stylesheets with maven

This simple example show how to set up a maven web application using SASS (.scss) stylesheets by compiling automatically on changing without restarting the server. The project structure: Maven configuration <project xmlns=”″ xmlns:xsi=”” xsi:schemaLocation=””> <modelVersion>4.0.0</modelVersion> <groupId>hu.daniel.hari.exercises</groupId> <artifactId>Tutorial-SassMavenAutoCompile</artifactId> <version>1.0</version> <packaging>war</packaging> <properties> <!– Generic properties –> <>UTF-8</> <java.version>1.7</java.version> <!– –> </properties> <dependencies> </dependencies> <build> <plugins> <plugin> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>${java.version}</source> <target>${java.version}</target> </configuration>… Read more »

Simple Spring Data JPA Example

With this simple example you can quick start with spring-data-jpa. This project has minimalistic design and focused to make easy to understand. What is spring-data-jpa for actually? You use @Repository interfaces instead of DAO Implementations, Less boilerplate coding of DAO classes for frequent operations like persisting, finding, listing, etc… You can define JPA queries by annotations like this: @Query(“select p from Product p where… Read more »