Class names in a nominal descriptor, like class names in the constant pool of a classfile, must be interpreted with respect to a particular class loader, which is not part of the nominal descriptor.

Static constants that are expressible natively in the constant pool (String,Integer,Long,Float, andDouble) implementConstantDesc, and serve as nominal descriptors for themselves. Native linkable constants (Class,MethodType, andMethodHandle) have counterpartConstantDesc types:ClassDesc,MethodTypeDesc, andMethodHandleDesc. Other constants are represented by subtypes ofDynamicConstantDesc.

APIs that perform generation or parsing of bytecode are encouraged to useConstantDesc to describe the operand of anldc instruction (including dynamic constants), the static bootstrap arguments of dynamic constants andinvokedynamic instructions, and other bytecodes or classfile structures that make use of the constant pool.

Constants describing various common constants (such asClassDesc instances for platform types) can be found inConstantDescs.

Implementations ofConstantDesc should be immutable and their behavior should not rely on object identity.

Non-platform classes should not implementConstantDesc directly. Instead, they should extendDynamicConstantDesc (asEnum.EnumDesc andVarHandle.VarHandleDesc do.)

Nominal descriptors should be compared using theObject.equals(Object) method. There is no guarantee that any particular entity will always be represented by the same descriptor instance.