JSR 199 and JSR 269 are standalone technologies and the primary use case is specific to IDEs that can run on the previous release of the platform e.g. JDK N and implement a Java compiler to support new language feature in JDK N+1.

java.compiler is upgradeable whereas jdk.compiler and langtools modules are not. javax.tools.ToolProvider::getSystemJavaCompiler should return the java compiler if jdk.compiler matches the version of java.compiler. This also applies to other relevant APIs such as getSystemDocumentationTool.