Articles Tagged ‘nosql’

Implementing, Testing and Running Procedures for Neo4j

Tuesday, February 27th, 2018

A lot of features are already included in the Neo4j graph database system but sometimes we want to extends its capabilities and implement functions and procedures by ourselves that we may reuse.

In the following tutorial I will demonstrate how to implement a procedure for Neo4j, how to write and run tests using JUnit and an embedded graph database and last but not least how to setup Neo4j with Docker and our stored procedure installed in no time.


Software Architecture Exploration and Validation with jqAssistant, Neo4j and Cypher

Sunday, December 31st, 2017

I have written about other software system analyzing and validation tools before but today I would like to introduce a new tool named jqAssistant that supports software architects, developers and analysts in a variety of tasks like analyzing given structures, validating architectural or quality constraints and generating reports.

Therefore jqAssistant analyzes given projects or artifacts and stores the gathered information – that is enriched by a variety of existing plugin-ins – in a Neo4j graph database.

This graph database may now be used to enforce architectural constraints or specific code metrics, to generate reports or to analyze a system with a nice browser interface.

In this tutorial I’m going to show how to integrate jqAssistant in an existing project using Maven as build-tool, how to explore an existing system step-by-step and finally how to enforce specific metrics by writing them down as a kind of living documentation in an AsciiDoc document.

I have also started to write down basic Cypher (the query language used) queries to analyze a system and other queries to gather basic metrics.


Elasticsearch Integration Testing with Java

Tuesday, August 23rd, 2016

When building up search engines, indexing tons of data into a schema-less, distributed data store, Elasticsearch has always been a favourite tool of mine.

In addition to its core features, it also offers tools and documentation for us developers when we need to write integration tests for our Elasticsearch powered Java applications.

In the following tutorial I’d like to demonstrate how to implement a small sample application using Elasticsearch under the hood and how to write integration-tests with these tools for this application afterwards.


Object Graph Mapping by Example with Neo4j OGM and Java

Monday, July 18th, 2016

When integrating a Neo4j database into a Java application a developer often needs to map nodes and edges of the graph to corresponding Java classes of the domain model.

Neo4j OGM eases this work and allows us to map our domain objects to the graph database using simple annotations – similar to the Java Persistence API (JPA) for relational database management systems.

In the following tutorial I’d like to demonstrate how to use Neo4j OGM to build a simple train timetable planner and a permission system mapping between graph, nodes, edges and POJOs.


Creating and Providing HipChat Integrations with Atlassian Connect, Nodejs and Express

Tuesday, August 18th, 2015

HipChat is Atlassian’s alternative to Slack and its solution to team collaboration chats. Atlassian Connect offers developer tools to bootstrap applications, connect to Atlassian’s cloud products with easy and in combination with HipChat’s REST APIs allows us to write integrations for such a chat server in no time.

In the following tutorial I’d like to show how to write an integration within a few steps using Atlassian Connect, Node.js and Express and how to connect the integration to a HipChat server.

Finally on the one hand I’m going to explain how to speed up local development with ngrok, an in-memory database and nodemon for automatic application restarts and on the other hand I’m going to demonstrate how to configure the application for production, running with a Redis key-value store on Heroku.


Writing Java Integration Tests for MongoDB

Wednesday, October 16th, 2013

MongoDB is matured, document-oriented, cross-platform NoSQL database system with drivers available for a bunch of different programming languages.

In the following short examples I’m going to write some integration tests for MongoDB using the MongoDB Java driver and the Flapdoodle library to create an embedded MongoDB instance for testing.

We’re going to write tests for a simple persist-and-query scenarion and for a map-reduce function and in addition I’m going to show how to bind the start and stop of a MongoDB  instance to a Maven goal using the embedmongo-maven-plugin.