How to mock value classes

I had an issue a couple of weeks ago while migrating some code from using bare Map[String, String] to a value class surrounding that map (HttpHeaders), and ran into issues with Mockito (even with the Specs2 helpers).

Long story short I was able to fix it with the following changes:

-any[HttpHeaders]
+Matchers.any(classOf[Map[_, _]]).asInstanceOf[HttpHeaders])

-when(request.headers)
-  .thenReturn(HttpHeaders.empty)
+when(request.headers.underlying)
+  .thenReturn(Map.empty[HttpHeader[_], Vector[String]])

How to sort in descending order on a field mapped to multiple database columns

Last August (2013) I ran into an issue where I wanted to get the latest 10 created entities from a database table but I was getting the first 10 instead. The relevant components of the stack involved were PostgreSQL 9.3, with Hibernate 4.2 used as the EntityManager provider for Spring Data JPA 1.4. Turns out that the cause is an old, obscure (but known) issue in Hibernate: HHH-5574.

My perfect blog: problem and solution

I like blogging from time to time, but I wish I could do things the way I like. One issue I have with having my blog here on wordpress is that I don’t have a local copy of it on my machine & it isn’t versioned in a repository (which has basically become my obsession). I wanted to find a solution that gave me these two things, and the flexibility to do anything else (such as in what markup to write the posts).

How I do (Java) development on Mac OS X

I just want to share how I set up to do development on my Mac OS X machine, specifically, in my case, Java development, especially my use of a local Homebrew root.

MySQL (v5.5) setup

This is how I setup a new MySQL database for a project (using a local HomeBrew root called sw):

unset TMPDIR
sw/bin/mysql_install_db --verbose --user=dnw \
  --basedir=sw/Cellar/mysql/5.5.20 --datadir=sw/var/mysql --tmpdir=/tmp
sw/bin/mysql.server start
create user [username]@localhost identified by '[password]';
create user [username] identified by '[password]';
grant all on *.* to [username]@localhost;
grant all on *.* to [username];

Creating a PostgreSQL database

Postgres is my favorite RDBMS, but I always forget how to setup a database. So this is mostly to remind myself 🙂

createuser --echo --no-createdb --encrypted --pwprompt --no-createrole \
  --no-superuser [ROLENAME]
createdb --echo --owner=[ROLENAME] [DBNAME]

Which echoes something like:

CREATE ROLE [ROLENAME] ENCRYPTED PASSWORD '[encrypted-password]' \
  NOSUPERUSER NOCREATEDB NOCREATEROLE INHERIT LOGIN;
CREATE DATABASE [DBNAME] OWNER [ROLENAME];

To connect use:

psql [DBNAME] [USERNAME]

That’s all 😀

Seperate Repositories: Acceptance Testing and Database Migrations

I have an issue in both the projects that I’m currently involved in and it has to do with debugging issues in previous versions of the application. In essence I cannot run an older version the application as my current database schema is newer than the model objects that map to it. Essentially I need a way to rollback a few database migration scripts so that I can run the application, or alternatively recreate a fresh database. This later solution should always be available, but as of now neither of them can be done. If the version I’m trying to run is the current production’s version, fortunately I can use a SQL dump of the production database to fix my error and allow the application to run.