org.apache.felix.prefs.impl
Class StreamBackingStoreImpl

java.lang.Object
  org.apache.felix.prefs.impl.StreamBackingStoreImpl

All Implemented Interfaces:

BackingStore

Direct Known Subclasses:

DataFileBackingStoreImpl

public abstract class StreamBackingStoreImpl
extends Object
implements BackingStore

This is an abstract implementation of a backing store which uses streams to read/write the preferences and stores a complete preferences tree in a single stream.

Field Summary

protected BundleContext

bundleContext The bundle context.

Constructor Summary

StreamBackingStoreImpl(BundleContext context)

Method Summary

protected abstract void	checkAccess() This method is invoked to check if the backing store is accessible right now.
protected abstract OutputStream	getOutputStream(PreferencesDescription desc) Get the output stream to write the preferences.
protected boolean	hasChanges(PreferencesImpl prefs) Has the tree changes?
protected void	read(PreferencesImpl prefs, InputStream is) Read the preferences recursively from the input stream.
protected void	readPreferences(PreferencesImpl prefs, InputStream in) Load this preferences from an input stream.
void	store(PreferencesImpl prefs) Store the current preferences and its children in the backing store.
void	update(PreferencesImpl prefs) Update the current preferences and its children from the backing store.
protected void	write(PreferencesImpl prefs, OutputStream os) Write the preferences recursively to the output stream.
protected void	writePreferences(PreferencesImpl prefs, OutputStream out) Save this preferences to an output stream.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.felix.prefs.BackingStore

availableBundles, load, loadAll, remove

Field Detail

bundleContext

protected final BundleContext bundleContext

The bundle context.

Constructor Detail

StreamBackingStoreImpl

public StreamBackingStoreImpl(BundleContext context)

Method Detail

checkAccess

protected abstract void checkAccess()
                             throws BackingStoreException

This method is invoked to check if the backing store is accessible right now.

Throws:

BackingStoreException

getOutputStream

protected abstract OutputStream getOutputStream(PreferencesDescription desc)
                                         throws IOException

Get the output stream to write the preferences.

Throws:

IOException

store

public void store(PreferencesImpl prefs)
           throws BackingStoreException

Description copied from interface: BackingStore

Store the current preferences and its children in the backing store. The store should check, if the preferences have changed, it should also check all children.

Specified by:

store in interface BackingStore

Parameters:

prefs - The preferences.

Throws:

BackingStoreException

See Also:

BackingStore.store(org.apache.felix.prefs.PreferencesImpl)

hasChanges

protected boolean hasChanges(PreferencesImpl prefs)

Has the tree changes?

update

public void update(PreferencesImpl prefs)
            throws BackingStoreException

Description copied from interface: BackingStore

Update the current preferences and its children from the backing store.

Specified by:

update in interface BackingStore

Throws:

BackingStoreException

See Also:

BackingStore.update(org.apache.felix.prefs.PreferencesImpl)

write

protected void write(PreferencesImpl prefs,
                     OutputStream os)
              throws IOException

Write the preferences recursively to the output stream.

Parameters:

prefs -

os -

Throws:

IOException

read

protected void read(PreferencesImpl prefs,
                    InputStream is)
             throws IOException

Read the preferences recursively from the input stream.

Parameters:

prefs -

is -

Throws:

IOException

readPreferences

protected void readPreferences(PreferencesImpl prefs,
                               InputStream in)
                        throws IOException

Load this preferences from an input stream. Currently the prefs are read from an object input stream and the serialization is done by hand. The changeSet is neither updated nor cleared in order to provide an update/sync functionality. This has to be done at a higher level.

Throws:

IOException

writePreferences

protected void writePreferences(PreferencesImpl prefs,
                                OutputStream out)
                         throws IOException

Save this preferences to an output stream. Currently the prefs are written through an object output stream with handmade serialization of strings. The changeSet is neither updated nor cleared in order to provide an update/sync functionality. This has to be done at a higher level.

Throws:

IOException