JDKonly

JDKonly is a term used to describe a development approach or tooling that aims to build software using only the Java Development Kit and its standard libraries, avoiding reliance on external third-party libraries or runtime dependencies. The concept emphasizes reproducibility, simplicity, and security by minimizing external surfaces.

Origin and scope: The idea has surfaced in contexts such as education, secure environments, and offline or air-gapped deployments, where network access and external dependencies are restricted. It aligns with the broader evolution of Java modularity, encouraging application boundaries that can be kept within the JDK modules.

Key characteristics: The approach involves using tools that ship with the JDK (such as javac, java, jlink, jdeps, and jshell) and structuring projects so they compile and run with only the standard library. Build strategies may favor plain javac or simple scripts, with optional use of jlink to produce a customized runtime image containing only the required modules. Third-party dependencies are avoided or minimized, and any required functionality is implemented with the standard library or vendored as JDK-compatible modules when feasible.

Advantages and limitations: JDKonly can improve build reproducibility, simplify security audits, and reduce maintenance in restricted environments. Its main limitation is the reduced access to the broader Java ecosystem of third-party libraries, which can constrain feature richness and increase development effort for otherwise readily available capabilities.

See also: Java Development Kit, Java SE, jlink, modularity, dependency management.