JEP 309 extends the existing Java class-file format, creating CONSTANT_Dynamic. This is a JVM feature and doesn't depend on the higher software layers. The loading of CONSTANT_Dynamic delegates the creation of a bootstrap method. When comparing it to the invokedynamic call, you will see how it delegates linking to a bootstrap method.

One of the main goals of dynamic class-file constants is to make it simple to create new forms of materializable class-file constants, which provides language designers and compiler implementers with broader options for expressivity and performance. This is achieved by creating a new constant pool form that can be parameterized using a bootstrap method with static arguments.