Java

Playing with the Spa

We have an Arctic Spa at our house which we enjoy. Recently, an OpenAPI spec has been published for it, so I decided to write a Java wrapper so I could control the spa myself, and monitor temperature with Prometheus and Grafana. The resulting code is here. The wrapper class “com.khubla.kspa.Spa” takes care of all the API details, so that status and control of the Spa is as simple as:

Ebean-DAO

When building database ORM code, I prefer to use ebean, and I prefer to use DAO’s. Since DAO’s are simple to make generic, I have a Generic DAO I use for all projects. I’ve finally decided to open-source my DAO code, and you can find it here https://github.com/teverett/ebean-dao.

DOT4J

I’ve recently been quite interested in Graph languages, not for Graph Databases, but for representing information, in code that is essentially “things” and “relationships”. For example, one perspective on Organizations is that they are simply representable as people, systems and the information that flows between them. Those three building blocks are, in theory, enough to describe anything from a small business to a government, if you have an appropriate way to describe all the information, ensure the connections make sense, and report on it. If you further layer on the idea of systems of systems, you have the ability to describe different levels of government, business units, departments and so on. Public and private flows of information allow models that accurately represent the fact that no organization is fully meshed: the systems only expose certain information. The reporting on it is quite interesting, and led to be becoming interested in DOT as a way to describe reports resulting from queries. I didn’t find a small, embeddable Java library that enabled me to read and write DOT files, so I ended up writing DOT4J. The writing of DOT files, is trivial. The reading however, ended up requiring a lexer-parser since DOT is, essentially a programming language of its own. The grammar came from ANTLR, of course. DOT4J is here. The Github page has the Maven co-ordinates for published binaries.

OpenAPI

I recently had reason to get to know OpenAPI at work, so I decided to become familiar with it. I have a HomeSeer home controller at home, which exposes a JSON API, so I decided to write a Java OpenAPI server to expose the JSON API over OpenAPI. The net result is hsOpenAPI. It exposes most of the HomeSeer API and uses hsClient, the Java wrapper I had previously built for the HomeSeer API.

Building a personal search engine

I recently got a call from a friend who has a library of thousands of PDF documents. He wanted to know there was a such thing as a personal search engine that could index his library of documents, and allow full text search inside of them. I have a giant document library too, including PDF documents, Office documents, source code, email and so on. I decided I needed one too, and it should be based on Elastic Search. The net result of the weekends work is “kSearch”, a personal search engine. kSearch include a threaded file system indexer, automatic maintainence of the search index as the file system changes, and a web search UI. You can see screen shots and source code on the github project.

K-REPL

A couple projects I’ve been working on have a need for a REPL style console.  I had written a simple framework for creating REPL’s, which is open-sourced here.  

A Java TELNET server

I recently had a reason to need a TELNET server and couldn’t find a Java library that worked for me.  After a weekend of hacking, I now have kTelnet, an Open-source, BSD-licensed, TELNET server.  

Quadrigacx API

I’ve recently become very interested in blockchain, and that, naturally led me to Ethereum and Bitcoin.  From there, I got a little interested in online trading, but since I prefer not to have to think about trading, I started thinking about a trading bot.  Part of the work I needed to do was write a Java API for Qaudrigacx.  The API is here and is free to use under the GPL v3 terms.  

khubla.com Java code released to Maven Central

I was recently asked to release some of my code to Maven Central, and therefore had to figure out how to do it.  I’ve now released these khubla.com libraries: cBean Pragmatach antlr4test-maven-plugin OLMReader simpleIOC ParadoxReader The maven coordinates for each are documented on the github pages.  

Outlook for Mac Archives

I recently had a reason to parse a large data set, for another project.  I decided that an ideal “large data set” would be my Outlook mail saved archives.  Sadly, Outlook for Mac doesn’t output PST files, it outputs OLM archives, which are, essentially, giant zip files full of XML.  I was coding this all in Java, so I needed a Java library to parse OLM files. The resulting source code is here.  Schema for OLM XML is here.