Environment on Micha Kops' Tech Notes

Handling System Properties, Environment Variables, STDOUT/STDERR in JUnit Tests with System Rules

Mon, 19 Dec 2016 00:00:00 +0100

When important data is written to STDIN/STDOUT and an application relies on specific system properties or environment variables, writing tests is getting more complicated.

System Rules is a collection of JUnit rules that helps us writing Java tests for everything that deals with java.lang.System.

In the following short examples I’d like to demonstrate how to deal with system properties, environment variables, STDOUT and STDERR and capturing both for testing e.g. for some golden master refactoring.

Using Java Config-Builder to assemble your Application Configuration

Tue, 20 May 2014 00:00:00 +0200

There’s a variety of configuration frameworks to use in our Java applications. Java Config Builder is one of them and it offers some nice features that I would like to demonstrate in the following short examples as are:

Loading values from different sources like property-files, environment variables, command-line-arguments or system properties, specifying default values, mapping arbitrary types or collections, merging configurations and using the Java Bean Validation standard aka JSR-303.

Linux Snippets

Mon, 01 Mar 2010 00:00:00 +0100

These are not only linux snippets but also bash snippets and snippets using tools that run under Linux, *nix or sometimes even MacOSX, I should reorder this article someday ;)

Settings for more reliable bash scripts

set -euo pipefail

this gives us …

-e: exit script if a single command fails
-u: exit script if an unset variable is used
-o pipefail: return value of a pipeline is the status of the last command to exit with a non-zero status, or zero if no command exited with a non-zero status

Spring Boot Snippets

Mon, 01 Mar 2010 00:00:00 +0100

Define and Configure Log Groups

This allows to configure a group of loggers at the same time

Define a log group named myaspect with two packages
application.properties
```
logging.group.myaspect=com.hascode.package1,com.hascode.package2
```
Configure the log group and set all loggers to level TRACE
application.properties
```
logging.level.myaspect=TRACE
```

This is also possible as parameter on startup

java -Dlogging.level.myaspect=TRACE myapp.jar

Use JUnit 5 with Spring Boot

Use newer versions of Surefire and Failsafe plugins:

<properties>
[..]
  <maven-failsafe-plugin.version>2.22.0</maven-failsafe-plugin.version>
  <maven-surefire-plugin.version>2.22.0</maven-surefire-plugin.version>
</properties>