The Descriptor Component provides sufficient information to parse and verify all elements of the CAP file. It references, and therefore describes, elements in the Constant Pool Component ( Section 6.7, Constant Pool Component), Class Component ( Section 6.8, Class Component), Method Component ( Section 6.9, Method Component), and Static Field Component ( Section 6.10, Static Field Component). No components in the CAP file reference the Descriptor Component.

The Descriptor Component is represented by the following structure:

The items of the descriptor_component structure are as follows:

tag

The tag item has the value COMPONENT_Descriptor (11).

size

The size item indicates the number of bytes in the descriptor_component structure, excluding the tag and size items. The value of the size item must be greater than zero.

class_count

The class_count item represents the number of entries in the classes table.

classes[]

The classes item represents a table of variable-length class_descriptor_info structures. Each class and interface defined in this package is represented in the table.

types

The types item represents a type_descriptor_info structure. This structure lists the set of field types and method signatures of the fields and methods defined or referenced in this package. Those referenced are enumerated in the Constant Pool Component.