org.glassfish.jersey.examples.feedcombiner.store

Class ReadWriteLockDataStore

java.lang.Object

org.glassfish.jersey.examples.feedcombiner.store.ReadWriteLockDataStore

All Implemented Interfaces:

InMemoryDataStore, ObservableDataStore

public class ReadWriteLockDataStore
extends Object
implements InMemoryDataStore, ObservableDataStore

A simple in-memory store for serializable values based on key. Implementation of the data store and their methods are thread-safe.

The data store provides the capability of an adding observers which are able to listen any changes in the data store.

Author:

Petr Bouda (petr.bouda at oracle.com)

Constructor Summary

Constructors

Constructor and Description
ReadWriteLockDataStore()

Method Summary

Modifier and Type	Method and Description
void	addObserver(DataStoreObserver observer) Adds an observer to the set of observers for this observable object ObservableDataStore.
void	deleteObserver(DataStoreObserver observer) Deletes an observer from the set of observers of this object.
<T extends Serializable> T	get(String key, Class<T> type) Retrieve data from the data store.
Collection<Serializable>	getAll()
void	load(InputStream in) Load content of the data store from an input stream.
<T extends Serializable> Serializable	put(String key, T data) Store new data or replace existing data stored under a key with the new data.
void	save(OutputStream out) Save current content of the data store to an output stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

ReadWriteLockDataStore

public ReadWriteLockDataStore()

Method Detail

put

public <T extends Serializable> Serializable put(String key,
                                                 T data)

Description copied from interface: InMemoryDataStore

Store new data or replace existing data stored under a key with the new data.

The method throws an exception if the key is null.

Specified by:

put in interface InMemoryDataStore

Parameters:

key - a unique identifier of the location where the data should be stored or replaced. Must not be null.

data - new data to be stored under the given key. May be null, in which case the data will be removed from the store.

Returns:

null if there are no data stored under the given key or any replaced data previously stored under the key.

get

public <T extends Serializable> T get(String key,
                                      Class<T> type)

Description copied from interface: InMemoryDataStore

Retrieve data from the data store.

The method retrieves the data stored under a unique key from the data store and returns the data cast into the Java type specified by type parameter.

Specified by:

get in interface InMemoryDataStore

Parameters:

key - a unique identifier of the location from which the stored data should be retrieved. Must not be null.

type - expected Java type of the data being retrieved. Must not be null.

Returns:

retrieved data or null if there are no data stored under the given key.

save

public void save(OutputStream out)
          throws IOException

Description copied from interface: InMemoryDataStore

Save current content of the data store to an output stream.

The operation is guaranteed to produce a consistent snapshot of the data store inner state.

Specified by:

save in interface InMemoryDataStore

Parameters:

out - output stream where the content of the data store is saved. The method does not close the stream.

Throws:

IOException - in case the save operation failed.

load

public void load(InputStream in)
          throws IOException

Description copied from interface: InMemoryDataStore

Load content of the data store from an input stream.

Any content previously stored in the data store will be discarded and replaced with the content loaded from the input stream.

Specified by:

load in interface InMemoryDataStore

Parameters:

in - input stream from which the content of the data store is loaded. The method does not close the stream.

Throws:

IOException - in case the load operation failed.

addObserver

public void addObserver(DataStoreObserver observer)

Description copied from interface: ObservableDataStore

Adds an observer to the set of observers for this observable object ObservableDataStore.

Specified by:

addObserver in interface ObservableDataStore

Parameters:

observer - an observer to be added.

deleteObserver

public void deleteObserver(DataStoreObserver observer)

Description copied from interface: ObservableDataStore

Deletes an observer from the set of observers of this object.

Passing null to this method will have no effect.

Specified by:

deleteObserver in interface ObservableDataStore

Parameters:

observer - the observer to be deleted.

getAll

public Collection<Serializable> getAll()