org.mapdb

Class EngineWrapper.CloseOnJVMShutdown

java.lang.Object

org.mapdb.EngineWrapper

org.mapdb.EngineWrapper.CloseOnJVMShutdown

All Implemented Interfaces:

Engine

Enclosing class:

EngineWrapper

public static class EngineWrapper.CloseOnJVMShutdown
extends EngineWrapper

Closes Engine on JVM shutdown using shutdown hook: Runtime.addShutdownHook(Thread) If engine was closed by user before JVM shutdown, hook is removed to save memory.

Nested Class Summary

Nested classes/interfaces inherited from class org.mapdb.EngineWrapper

EngineWrapper.CloseOnJVMShutdown, EngineWrapper.ImmutabilityCheckEngine, EngineWrapper.ReadOnlyEngine, EngineWrapper.SerializerCheckEngineWrapper, EngineWrapper.SynchronizedEngineWrapper

Field Summary

Fields

Modifier and Type	Field and Description
(package private) java.lang.Thread	hook
(package private) java.lang.Runnable	hookRunnable
protected java.util.concurrent.atomic.AtomicBoolean	shutdownHappened

Fields inherited from class org.mapdb.EngineWrapper

CLOSED

Fields inherited from interface org.mapdb.Engine

CATALOG_RECID, CHECK_RECORD, CLASS_INFO_RECID, LAST_RESERVED_RECID

Constructor Summary

Constructors

Constructor and Description
CloseOnJVMShutdown(Engine engine)

Method Summary

Modifier and Type	Method and Description
void	close() Close store/cache.

Methods inherited from class org.mapdb.EngineWrapper

canRollback, canSnapshot, checkClosed, clearCache, closeListenerRegister, closeListenerUnregister, commit, compact, compareAndSwap, delete, get, getSerializerPojo, getWrappedEngine, isClosed, isReadOnly, preallocate, preallocate, put, rollback, snapshot, update

Methods inherited from class java.lang.Object

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

Field Detail

shutdownHappened

protected final java.util.concurrent.atomic.AtomicBoolean shutdownHappened

hookRunnable

final java.lang.Runnable hookRunnable

hook

java.lang.Thread hook

Constructor Detail

CloseOnJVMShutdown

public CloseOnJVMShutdown(Engine engine)

Method Detail

close

public void close()

Description copied from interface: Engine

Close store/cache. This method must be called before JVM exits to flush all caches and prevent store corruption. Also it releases resources used by MapDB (disk, memory..).

Engine can no longer be used after this method was called. If Engine is used after closing, it may throw any exception including NullPointerException

There is an configuration option DBMaker.closeOnJvmShutdown() which uses shutdown hook to automatically close Engine when JVM shutdowns.

Specified by:

close in interface Engine

Overrides:

close in class EngineWrapper