Java framework Spring Boot 2.3 extends the connection to Docker

Spring Boot 2.3

Spring Boot, the extension for the Java Framework Spring, which allows developers to create Java applications on their own, has been released in version 2.3. The release brings a few innovations in conjunction with Docker. In addition, the Graceful Shutdown now works in conjunction with all embedded web servers.

Spring Boot 2.3.0 was released

The release updates some dependencies and links to third-party tools and libraries. On the Java side, Spring Boot 2.3 relies on Java 14, but continues to work with versions 8 and 11 of the programming language.

Layer in the container

In combination with Docker, Cloud Native Buildpacks can now be used. To create a suitable OCI image (Open Container Initiative), Maven and Gradle plug-ins exist via the spring-boot:build-image target and the bootBuildImage task. By default, Spring Boot uses Paketo to create buildpacks.

An important infrastructural innovation is the option to pack Layerd Jars in containers. Splitting into layers is more efficient, especially for Java applications that change frequently, than using a single Fat Jar that contains the complete application code and the required Java libraries. Thanks to the layered concept, the framework can reuse the unchanged jars when building a container image and only needs to create the packages fresh with new content.

Gentle switch off

Graceful Shutdown now works with all four web servers embedded in Spring Boot: Jetty, Reactor Netty, Tomcat and Undertow. The method should ensure that outstanding tasks are completed before shutting down. On the hard shutdown enabled by default, Spring’s Taskexecutor interrupts all running tasks.

In contrast, developers or administrators define a grace period for the graceful shutdown. The mentioned web servers do not accept new requests from the start of the smooth shutdown, but the current requests receive the additional time to process and complete open requests.

Updated dependencies

Spring Boot also includes numerous updated dependencies, including last week’s release of Spring Data Neumann, which takes its name from the Hungarian-American computer scientist Klára Dán Neumann and is based on the IntelFounder Moore named release follows.

In addition, version 2.3 includes updated dependencies for the spring packages HATEOAS 1.1, Integration 5.3, Kafka 2.5, Security 5.3 and Session Dragonfruit. Regarding the external connections, there are updates for Cassandra Driver 4.6, Couchbase Client 3.0, Elasticsearch 7.6, Kafka 2.5, Micrometer 1.5 and Mongodb 4.0.

Further innovations and changes in Spring Boot 2.3 can be found in the Spring.