Class ModuleLayer.Controller

java.lang.Object

java.lang.ModuleLayer.Controller

Enclosing class:

ModuleLayer

public static final class ModuleLayer.Controller
extends Object

Controls a module layer. The static methods defined by ModuleLayer to create module layers return a Controller that can be used to control modules in the layer.

Unless otherwise specified, passing a null argument to a method in this class causes a NullPointerException to be thrown.

API Note:

Care should be taken with Controller objects, they should never be shared with untrusted code.

Since:

9

Method Summary

Modifier and Type	Method	Description
ModuleLayer.Controller	addExports(Module source, String pn, Module target)	Updates module source in the layer to export a package to module target.
ModuleLayer.Controller	addOpens(Module source, String pn, Module target)	Updates module source in the layer to open a package to module target.
ModuleLayer.Controller	addReads(Module source, Module target)	Updates module source in the layer to read module target.
ModuleLayer.Controller	enableNativeAccess(Module target)	Restricted. Enables native access for a module in the layer if the caller's module has native access.
ModuleLayer	layer()	Returns the layer that this object controls.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Modifier and Type	Method	Description
protected Object	clone()	Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. May cause performance issues, deadlocks and hangs.
final Class<? extends Object>	getClass()	Answers the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode()	Answers an integer hash code for the receiver.
final void	notify()	Causes one thread which is waiting on the receiver to be made ready to run.
final void	notifyAll()	Causes all threads which are waiting on the receiver to be made ready to run.
String	toString()	Answers a string containing a concise, human-readable description of the receiver.
final void	wait()	Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
final void	wait(long time)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
final void	wait(long time, int frac)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

Method Details

layer

public ModuleLayer layer()

Returns the layer that this object controls.

Returns:

the module layer

addReads

public ModuleLayer.Controller addReads(Module source,
 Module target)

Updates module source in the layer to read module target. This method is a no-op if source already reads target.

Implementation Note:

Read edges added by this method are weak and do not prevent target from being GC'ed when source is strongly reachable.

Parameters:

source - The source module

target - The target module to read

Returns:

This controller

Throws:

IllegalArgumentException - If source is not in the module layer

See Also:

• Module.addReads(Module)

addExports

public ModuleLayer.Controller addExports(Module source,
 String pn,
 Module target)

Updates module source in the layer to export a package to module target. This method is a no-op if source already exports the package to at least target.

Exporting a package with this method does not allow the target module to reflectively set or obtain a method handle with write access to a public final field declared in a public class in the package.

Parameters:

source - The source module

pn - The package name

target - The target module

Returns:

This controller

Throws:

IllegalArgumentException - If source is not in the module layer or the package is not in the source module

See Also:

• Module.addExports(String, Module)

addOpens

public ModuleLayer.Controller addOpens(Module source,
 String pn,
 Module target)

Updates module source in the layer to open a package to module target. This method is a no-op if source already opens the package to at least target.

Opening a package with this method does not allow the target module to reflectively set or obtain a method handle with write access to a final field declared in a class in the package.

Parameters:

source - The source module

pn - The package name

target - The target module

Returns:

This controller

Throws:

IllegalArgumentException - If source is not in the module layer or the package is not in the source module

See Also:

• Module.addOpens(String, Module)

enableNativeAccess

public ModuleLayer.Controller enableNativeAccess(Module target)

enableNativeAccess is a restricted method of the Java platform.

Programs can only use enableNativeAccess when access to restricted methods is enabled.

Restricted methods are unsafe, and, if used incorrectly, might crash the JVM or result in memory corruption.

Enables native access for a module in the layer if the caller's module has native access.

Parameters:

target - The module to update

Returns:

This controller

Throws:

IllegalArgumentException - If target is not in the module layer

IllegalCallerException - If the caller is in a module that does not have native access enabled

Since:

22