org.mycore.datamodel.ifs
Class MCRContentStore

java.lang.Object
  org.mycore.datamodel.ifs.MCRContentStore

Direct Known Subclasses:

MCRCStoreVFS, MCRCStoreVideoCharger, MCRHIBCStore

public abstract class MCRContentStore
extends Object

Stores the content of MCRFiles in a persistent datastore. This can be a filesystem, IBM Content Manager, video streaming servers like IBM VideoCharger or Real Server, depending on the class that implements this interface. The MCRContentStore provides methods to store, delete and retrieve content. It uses a storage ID and the store ID to identify the place where the content of a file is stored.

Version:

$Revision: 14354 $ $Date: 2008-11-07 15:23:02 +0100 (Fr, 07 Nov 2008) $

Author:

Frank Lützenkirchen

Field Summary

protected static DateFormat	formatter DateFormat used to construct new unique IDs based on timecode
protected static String	lastTimestamp The last timestamp that was constructed
protected String	prefix The prefix of all properties in mycore.properties for this store
protected int	slotDirDepth The depth of slot subdirectories to build
protected String	storeID The unique store ID for this MCRContentStore implementation

Constructor Summary

MCRContentStore()
Default constructor *

Method Summary

protected static String	buildNextID(MCRFileReader file) Constructs a new unique ID for storing content
protected static String	buildNextTimestamp() Helper method for constructing a unique storage ID from a timestamp.
protected String[]	buildSlotPath() Some content store implementations store the file's content in a hierarchical directory structure of the server's filesystem.
void	deleteContent(String storageID) Deletes the content of an MCRFile object that is stored under the given Storage ID in this store instance.
protected abstract void	doDeleteContent(String storageID) Deletes the content of an MCRFile object that is stored under the given Storage ID in this store instance.
protected abstract InputStream	doRetrieveContent(MCRFileReader file) Retrieves the content of an MCRFile.
protected abstract void	doRetrieveContent(MCRFileReader file, OutputStream target) Deprecated. use doRetrieveContent(MCRFileReader file) instead
protected abstract String	doStoreContent(MCRFileReader file, MCRContentInputStream source) Stores the content of an MCRFile by reading from an MCRContentInputStream.
String	getID() Returns the unique store ID that was set for this store instance
void	init(String storeID) Initializes the store and sets its unique store ID.
InputStream	retrieveContent(MCRFileReader file) Retrieves the content of an MCRFile as an InputStream.
void	retrieveContent(MCRFileReader file, OutputStream target) Deprecated. use doRetrieveContent(MCRFileReader file) instead
String	storeContent(MCRFileReader file, MCRContentInputStream source) Stores the content of an MCRFile by reading from an MCRContentInputStream.

Methods inherited from class java.lang.Object

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

Field Detail

storeID

protected String storeID

The unique store ID for this MCRContentStore implementation

prefix

protected String prefix

The prefix of all properties in mycore.properties for this store

slotDirDepth

protected int slotDirDepth

The depth of slot subdirectories to build

formatter

protected static DateFormat formatter

DateFormat used to construct new unique IDs based on timecode

lastTimestamp

protected static String lastTimestamp

The last timestamp that was constructed

Constructor Detail

MCRContentStore

public MCRContentStore()

Default constructor *

Method Detail

init

public void init(String storeID)

Initializes the store and sets its unique store ID. MCRFiles must remember this ID to indentify the store that holds their file content. The store ID is set by MCRContentStoreFactory when a new store instance is built. Subclasses should override this method.

Parameters:

storeID - the non-null unique store ID for this store instance

getID

public String getID()

Returns the unique store ID that was set for this store instance

Returns:

the unique store ID that was set for this store instance

storeContent

public String storeContent(MCRFileReader file,
                           MCRContentInputStream source)
                    throws MCRPersistenceException

Stores the content of an MCRFile by reading from an MCRContentInputStream. Returns a StorageID to indentify the place where the content was stored.

Parameters:

file - the MCRFile thats content is to be stored

source - the ContentInputStream where the file content is read from

Returns:

an ID that indentifies the place where the content was stored

Throws:

MCRPersistenceException

doStoreContent

protected abstract String doStoreContent(MCRFileReader file,
                                         MCRContentInputStream source)
                                  throws Exception

Stores the content of an MCRFile by reading from an MCRContentInputStream. Returns a StorageID to indentify the place where the content was stored.

Parameters:

file - the MCRFile thats content is to be stored

source - the ContentInputStream where the file content is read from

Returns:

an ID that indentifies the place where the content was stored

Throws:

Exception

deleteContent

public void deleteContent(String storageID)
                   throws MCRException

Deletes the content of an MCRFile object that is stored under the given Storage ID in this store instance.

Parameters:

storageID - the storage ID of the MCRFile object

Throws:

MCRException

doDeleteContent

protected abstract void doDeleteContent(String storageID)
                                 throws Exception

Deletes the content of an MCRFile object that is stored under the given Storage ID in this store instance.

Parameters:

storageID - the storage ID of the MCRFile object

Throws:

Exception

retrieveContent

public void retrieveContent(MCRFileReader file,
                            OutputStream target)
                     throws MCRException

Deprecated. use doRetrieveContent(MCRFileReader file) instead

Retrieves the content of an MCRFile to an OutputStream. Uses the StorageID to indentify the place where the file content was stored in this store instance.

Parameters:

file - the MCRFile thats content should be retrieved

target - the OutputStream to write the file content to

Throws:

MCRException

doRetrieveContent

protected abstract void doRetrieveContent(MCRFileReader file,
                                          OutputStream target)
                                   throws Exception

Deprecated. use doRetrieveContent(MCRFileReader file) instead

Retrieves the content of an MCRFile to an OutputStream. Uses the StorageID to indentify the place where the file content was stored in this store instance.

Parameters:

file - the MCRFile thats content should be retrieved

target - the OutputStream to write the file content to

Throws:

Exception

doRetrieveContent

protected abstract InputStream doRetrieveContent(MCRFileReader file)
                                          throws Exception

Retrieves the content of an MCRFile. Uses the StorageID to indentify the place where the file content was stored in this store instance.

Parameters:

file - the MCRFile thats content should be retrieved

Throws:

Exception

Since:

1.3

retrieveContent

public InputStream retrieveContent(MCRFileReader file)
                            throws MCRException

Retrieves the content of an MCRFile as an InputStream.

Parameters:

file - the MCRFile thats content should be retrieved

Throws:

MCRException

buildNextID

protected static String buildNextID(MCRFileReader file)

Constructs a new unique ID for storing content

buildNextTimestamp

protected static String buildNextTimestamp()

Helper method for constructing a unique storage ID from a timestamp.

buildSlotPath

protected String[] buildSlotPath()

Some content store implementations store the file's content in a hierarchical directory structure of the server's filesystem. Such stores use a directory that contains 100 subdirectories with each 100 subsubdirectories, so that the internal directory operations will scale well for large file collections. The depth of this subdirectory structure can be set by the property SlotDirDepth, default is 2. This helper method randomly chooses the "slot directory" to be used for the next storage.

Returns:

directory names between "00" and "99" that are the "slot" where to store the file's content in the filesystem.