ModuleReference (Java SE 9 & JDK 9 )

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 Summary

Constructors
Modifier Constructor Description

protected ModuleReference(ModuleDescriptor descriptor, URI ___location)
Constructs a new instance of this class.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`ModuleDescriptor`	`descriptor()`	Returns the module descriptor.
`Optional<URI>`	`___location()`	Returns the ___location of this module's content, if known.
`abstract ModuleReader`	`open()`	Opens the module content for reading.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - 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 Detail
  - 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