I am structuring a complex application with shared libraries. Can anyone explain how to eliminate the "no main manifest attribute" error when trying to run a Java JAR file that belongs to a specific sub-module while ensuring the base library modules remain non-executable?
3 answers
Managing configurations across multiple levels requires isolating your build instructions. To fix this, you must apply the executable packaging plugins exclusively to the specific sub-project that contains your application entry point. For your utility modules, ensure they use standard library packaging rules without declaring a main class. This prevents the compiler from attempting to add execution headers to components that are only meant to serve as classpath dependencies for the primary application.
That separates the builds cleanly, but what if my primary module needs to pull resources dynamically from those secondary sub-directories at runtime? Won't isolating the configurations break the internal paths?
For massive multi-level project trees, utilizing global configuration injectors can help you assign specific compilation rules cleanly based on module names.
Agreed, Stephanie. Using centralized build inheritance simplifies properties management across complex hierarchies, making the elimination of execution errors much easier to maintain over long development lifecycles.
Patrick, isolating the configuration won't break anything. As long as your primary module lists the sub-projects as formal compilation dependencies, the build engine automatically maps their class paths into the final executable layout. The main manifest file only needs to point to the core entry class.