Chapter 9. Packaging your application

An uberjar is a single Java .jar file that includes everything you need to execute your application. This means both the runtime components you have selected—​you can understand that as the app server—​along with the application components (your .war file).

An uberjar is useful for many continuous integration and continuous deployment (CI/CD) pipeline styles, in which a single executable binary artifact is produced and moved through the testing, validation, and production environments in your organization.

The names of the uberjars that Thorntail produces include the name of your application and the -thorntail.jar suffix.

An uberjar can be executed like any executable JAR:

java -jar myapp-thorntail.jar

$ java -jar myapp-thorntail.jar

A hollow JAR is similar to an uberjar, but includes only the runtime components, and does not include your application code.

A hollow jar is suitable for deployment processes that involve Linux containers such as Docker. When using containers, place the runtime components in a container image lower in the image hierarchy—​which means it changes less often—​so that the higher layer which contains only your application code can be rebuilt more quickly.

The names of the hollow JARs that Thorntail produces include the name of your application, and the -hollow-thorntail.jar suffix. You must package the .war file of your application separately in order to benefit from the hollow JAR.

When executing the hollow JAR, provide the application .war file as an argument to the Java binary:

java -jar myapp-hollow-thorntail.jar myapp.war

$ java -jar myapp-hollow-thorntail.jar myapp.war

<dependency>
    <groupId>io.thorntail.servers</groupId>
    <artifactId>[web|microprofile]</artifactId>
</dependency>

<dependency>
    <groupId>io.thorntail.servers</groupId>
    <artifactId>[web|microprofile]</artifactId>
</dependency>