Tech

These days where a cheap GPU for about 100 € is capable to create 3 billion of MD5 Hashes per second, we need not only need to use salts the right way but we also need to choose a strong, non-reversible and slow hashing schemes when storing passwords in our application. Heimdall is a library that implements a secure and upgradable password hashing mechanism and uses at the time of writing this article PBKDF2 SHA-1 HMAC with 20000 iterations and a 192 bit (24 byte) salt per default. ...

Spring Boot allows us to create RESTful web-services with ease, Swagger specifies a format to describe the capabilities and operations of these services and with Swagger UI it is possible to explore our REST API with a nice graphical user interface in our browser. Springfox is a project that aims at creating automated JSON API documentation for API’s built with Spring and is used in the following tutorial to integrate Swagger into a sample application. ...

A variety of different tools exists to help us analyze RESTful web-services and create documentations for their APIs in different formats. In the following tutorial I’d like to demonstrate how to document an existing JAX-RS web-service in multiple formats like Swagger, AsciiDoc or Plain Text using Maven, the JAX-RS Analyzer and the JAX-RS Analyzer Maven Plugin. The JAX-RS Analyzer gathers its information not only by reflection like most other tools but also by bytecode analysis and therefore does not require us to add special annotations for documentation to our code. ...

Mutation testing makes an interesting addition to the classical test coverage metrics. They seed mutations (errors) into the code, run the project’s tests afterwards and if the tests fail, the mutation is killed – otherwise it lived and we have a possible indication of an issue with our tests. In the following short tutorial. I’d like to demonstrate how to setup mutation tests with the PIT/Pitest library and Maven and generate reports. ...

Nowadays in the realm of hybrid mobile application development there is a variety of available frameworks worth having a look at. In the following tutorial I’d like to demonstrate the development life-cycle for a complete mobile application using Ionic, Cordova and AngularJS (and others) covering every step from the initial project setup, creating Angular Controllers, Directives, adding Cordova Plug-Ins, running and testing the application in the browser and emulator up to finally running the application on an Android device and assembling files for a release. ...

Using immutable objects in Java (and other programming languages as well) is a good thing because immutable objects may be shared safely, are thread-safe and reduce the risk of side effects in your applications. Nowadays multiple frameworks exist to reduce the need of writing boilerplate code here but there is one special framework whose features I’d like to demonstrate in the following short tutorial. It hooks into your application using annotation processing and generates type-safe builders, toString, hashCode, equals methods for you, supports lazy attributes, singleton instances, serialization into data-formats like JSON and a lot of other features,too. ...

Sometimes when writing an application we might consider using an in-memory file system to speed up data access or to create some kind of cache. There are different libraries to help us here but one looks especially promising for me because it supports almost every functionality of the Java NIO File APIs added in Java 7 – from creating, reading, deleting files and directory to handling symbolic and hard links or watching directory changes with a WatchService. ...

For the most of us developers, generating Java source files is an occasionally happening task and we’re dealing with it e.g. when writing annotation processors, writing tools or interacting with meta-data files. JavaPoet is a nice library to simplify such tasks, offering an intuitive fluent-builder API to generate source files in no time. In the following tutorial I’d like to share a few examples by writing code generators with the help of this library. ...

When it comes to indexing in a Neo4j graph database, different options exist for a developer to create and maintain the index. In the following short examples I’d like to demonstrate different possibilities for index management. Figure 1. Simple Domain Model Dependencies Only one dependency is needed to run the following examples and start an embedded neo4j server – I’m using Gradle here to manage my dependencies but Maven, Ivy, SBT should work without a problem, too. ...

When there is the need to create load tests or performance tests for an application, Apache JMeter is a handy tool and set up with ease. In the following short tutorial I’d like to demonstrate how to configure JMeter to log into a Java EE web application with multiple users specified in a CSV file, how to generate some basic reports and how to integrate JMeter into a mavenized build using the JMeter Maven Plugin. ...