org.mozilla.jss.util

Class NativeEnclosure

java.lang.Object

org.mozilla.jss.util.NativeEnclosure

All Implemented Interfaces:

java.lang.AutoCloseable

Direct Known Subclasses:

CKAttribute, KBKDFDataParameter, KBKDFDerivedKey, KBKDFParameterSpec

public abstract class NativeEnclosure
extends java.lang.Object
implements java.lang.AutoCloseable

Classes extending NativeEnclsoure wrap a single NativeProxy instance, allowing it to be accessed from the JNI layer but be allocated and scoped from the Java layer. Because this class implements AutoCloseable, it is suggested to add constructors to derived classes which call open; this'll allow a single try-with-resources block to scope the lifetime of this object:

 try (NEC obj = new NEC(...)) {
      // ... do something with obj ...
 }
 

Extending classes implement acquireNativeResources() and releaseNativeResources(). Before this instance is passed to the JNI layer, open() should be called, allocating all necessary resources. After making all necessary JNI calls, close() should be called to free resources. Ideally, open() and close() should be called close to the JNI calls, wrapped by the developer to limit accidental memory leaks.

Field Summary

Fields

Modifier and Type	Field and Description
NativeProxy	mPointer Enclosed NativeProxy reference.
long	mPointerSize Size of enclosed mPointer.

Constructor Summary

Constructors

Constructor and Description
NativeEnclosure()

Method Summary

Modifier and Type	Method and Description
protected abstract void	acquireNativeResources() Allocate native resources, setting mPointer and mPointerSize as appropriate.
void	close() Deinitialize and free mPointer.
protected void	finalize() Deprecated.
void	open() Allocate and initialize mPointer with its enclosed value.
protected abstract void	releaseNativeResources() Called to deallocate native resources; note that mPointer.close() is called afterwards.

Methods inherited from class java.lang.Object

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

Field Detail

mPointer

public NativeProxy mPointer

Enclosed NativeProxy reference.

mPointerSize

public long mPointerSize

Size of enclosed mPointer.

Constructor Detail

NativeEnclosure

public NativeEnclosure()

Method Detail

open

public final void open()
                throws java.lang.Exception

Allocate and initialize mPointer with its enclosed value. Note that this method prevents you from accidentally leaking memory; to call open() twice, call close() first.

Throws:

java.lang.Exception

finalize

@Deprecated
protected void finalize()
                             throws java.lang.Throwable

Deprecated.

Overrides:

finalize in class java.lang.Object

Throws:

java.lang.Throwable

close

public final void close()
                 throws java.lang.Exception

Deinitialize and free mPointer. Must be called to prevent memory leaks.

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.lang.Exception

acquireNativeResources

protected abstract void acquireNativeResources()
                                        throws java.lang.Exception

Allocate native resources, setting mPointer and mPointerSize as appropriate.

Throws:

java.lang.Exception

releaseNativeResources

protected abstract void releaseNativeResources()
                                        throws java.lang.Exception

Called to deallocate native resources; note that mPointer.close() is called afterwards. If mPointer.close() should be a no-op, extend from StaticVoidRef and do any required cleanup here.

Throws:

java.lang.Exception