Properties

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. ...

Though having written about other configuration management libraries for Java before, I would like to demonstrate another one today: Netflix Archaius. Archaius offers some nice features like dynamic typed properties, thread-safe operations, an event system for property changes/updates, a JMX MBean to read and update properties and adaptors for a variety of dynamic configuration sources like Amazon DynamoDB, JDBC, URLs and Apache ZooKeeper. In the following tutorial I’d like to demonstrate how to read and update application configuration properties with Archaius and data sources like property-files, system-properties, JMX and Apache ZooKeeper. ...

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. ...

Remote Debug a Pod’s Java Process Simple steps for remote debugging a Java process running on a k8 pod: Edit deployment and add the following parameters to the Java start line: -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=127.0.0.1:5005 Also add the following port mapping at the section container → ports in the deployment: - containerPort: 5005 protocol: TCP Safe, wait for the new pods and then add a port forward for port 5005 for this pod: kubectl port-forward podname 5005 ...

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> ...