The build process is first of all responsible for compiling the sources of a Java software project into bytecode. This happens every time changes have been made to the project. All modern build systems ship with useful conventions to minimize the required configuration.

In the enterprise world, with all its different frameworks and libraries, an important step is to organize and define all dependencies on APIs and implementations. Build tools such as Apache Maven or Gradle support developers by including powerful dependency resolution mechanisms. The build tool adds all the dependencies with the corresponding versions required to compile or run the application, respectively. This simplyfies to setup the project among multiple developers. It also enables repeatable builds.

Packaging the compiled classes and their dependencies into deployment artifacts is also part of the build process. Depending on the used technology the artifacts are packaged as WAR or JAR files. Chapter 4, Lightweight Java EE will discuss the different ways of packaging Java enterprise applications together with their pros and cons.

The topics, Gradle and Apache Maven, will discuss the implementation and differences of the two main build systems in more depth.