Module java.base
Package java.lang.module

Class ModuleReference

java.lang.Object
java.lang.module.ModuleReference
public abstract class ModuleReference
extends Object
A reference to a module's content.

A module reference is a concrete implementation of this class that implements the abstract methods defined by this class. It contains the module's descriptor and its location, if known. It also has the ability to create a ModuleReader in order to access the module's content, which may be inside the Java run-time system itself or in an artifact such as a modular JAR file.

Since:
9
See Also:
ModuleFinder, ModuleReader

  • Constructor Details

    • ModuleReference

      protected ModuleReference​(ModuleDescriptor descriptor, URI location)
      Constructs a new instance of this class.
      Parameters:
      descriptor - The module descriptor
      location - The module location or null if not known

  • Method Details

    • descriptor

      public final ModuleDescriptor descriptor()
      Returns the module descriptor.
      Returns:
      The module descriptor

    • location

      public final Optional<URI> location()
      Returns the location of this module's content, if known.

      This URI, when present, can be used as the location value of a CodeSource so that a module's classes can be granted specific permissions when loaded by a SecureClassLoader.

      Returns:
      The location or an empty Optional if not known

    • open

      public abstract ModuleReader open() throws IOException
      Opens the module content for reading.
      Returns:
      A ModuleReader to read the module
      Throws:
      IOException - If an I/O error occurs
      SecurityException - If denied by the security manager