com.trendmicro.grid.acl.ds
Interface FileContentRepository

All Superinterfaces:

Repository

public interface FileContentRepository
extends Repository

Defines an abstraction layer on top of a physical repository of files.

Version:

1.0

Author:

juergen_kellerer, 2010-05-05

Method Summary

void	attachProperties(byte[] hashKey, Map<String,String> properties) Attaches the specified properites to the file identified by the hash.
byte[]	createTemporaryHashKey() Creates a temporary hash key for the given file.
byte[]	decodeFromInternalURI(URI internalURI) Decodes the hash key from a sharable network or machine internal URI.
byte[]	decodeHashKey(String hashKey) Decodes the hash key from string.
String	encodeHashKey(byte[] hashKey) Encodes the hash key to string.
URI	encodeToInternalURI(byte[] hashKey) Encodes the hash key to a sharable network or machine internal URI.
String	getHashKeyAlgorithm() Returns the name of the MessageDigest algorithm used for creating hashKeys.
Date	getLastModified(byte[] hashKey) Returns the time of the last modification.
boolean	isExisting(byte[] hashKey) Returns true if the file exists inside the underlying repository.
MessageDigest	newHashKeyDigest() Returns a new instance of the MessageDigest used for creating hashKeys.
InputStream	openForRead(byte[] hashKey) Returns true if the file exists inside the underlying repository.
DigestOutputStream	openForWrite(byte[] hashKey) Opens the specified file for writing.
Map<String,String>	readProperties(byte[] hashKey) Reads previously attached properties.
void	rename(byte[] fromHashKey, byte[] toHashKey) Renames the specified resource, if possible.

Method Detail

getHashKeyAlgorithm

String getHashKeyAlgorithm()

Returns the name of the MessageDigest algorithm used for creating hashKeys.

Returns:

the name of the MessageDigest algorithm used for creating hashKeys.

newHashKeyDigest

MessageDigest newHashKeyDigest()

Returns a new instance of the MessageDigest used for creating hashKeys.

Returns:

a new instance of the MessageDigest used for creating hashKeys.

isExisting

boolean isExisting(byte[] hashKey)

Returns true if the file exists inside the underlying repository.

Parameters:

hashKey - the hash key identifying the file.

Returns:

true if the file exists inside the underlying repository.

getLastModified

Date getLastModified(byte[] hashKey)

Returns the time of the last modification.

Parameters:

hashKey - the hash key identifying the file.

Returns:

the time of the last modification or 'null' if the file doesn't exist.

openForWrite

DigestOutputStream openForWrite(byte[] hashKey)
                                throws FileNotFoundException,
                                       IllegalStateException

Opens the specified file for writing.

Note: The returned DigestOutputStream will compute the final hashKey during the write operation. out.getMessageDigest().digest() can be used to retrieve the final hashKey for a resource stored with a temporary key.

Parameters:

hashKey - the hash key identifying the file.

Returns:

a DigestOutputStream to write the content to.

Throws:

FileNotFoundException - if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason

IllegalStateException - In case of the repository doesn't allow to write to the specified resource. May happen in write once repositories, when an attempt is made to overwrite a resource)

attachProperties

void attachProperties(byte[] hashKey,
                      Map<String,String> properties)
                      throws IOException

Attaches the specified properites to the file identified by the hash.

Parameters:

hashKey - the hash key identifying the file.

properties - the properties to attach to the file.

Throws:

IOException - in case of attaching the properties failed.

openForRead

InputStream openForRead(byte[] hashKey)
                        throws FileNotFoundException

Returns true if the file exists inside the underlying repository.

Parameters:

hashKey - the hash key identifying the file.

Returns:

true if the file exists inside the underlying repository.

Throws:

FileNotFoundException - In case of the file, identified by the hashKey does not exist.

readProperties

Map<String,String> readProperties(byte[] hashKey)
                                  throws IOException

Reads previously attached properties.

Parameters:

hashKey - the hash key identifying the file.

Returns:

the properties attached to the file or 'null' if none were attached.

Throws:

FileNotFoundException - In case of the file, identified by the hashKey does not exist.

IOException

rename

void rename(byte[] fromHashKey,
            byte[] toHashKey)
            throws FileNotFoundException,
                   IllegalArgumentException

Renames the specified resource, if possible.

Parameters:

fromHashKey - The key identifying the resource to be renamed,

toHashKey - The new name of the resource.

Throws:

IllegalArgumentException - In case of a resource is renamed to a name that is considered invalid by the repository.

FileNotFoundException - In case of the file, identified by the hashKey does not exist.

createTemporaryHashKey

byte[] createTemporaryHashKey()

Creates a temporary hash key for the given file.

Returns:

true if the file exists inside the underlying repository.

encodeToInternalURI

URI encodeToInternalURI(byte[] hashKey)

Encodes the hash key to a sharable network or machine internal URI.

Parameters:

hashKey - the hash key identifying the file.

Returns:

a sharable network or machine internal URI.

decodeFromInternalURI

byte[] decodeFromInternalURI(URI internalURI)

Decodes the hash key from a sharable network or machine internal URI.

Parameters:

internalURI - a sharable network or machine internal URI.

Returns:

the decoded hash key, or 'null' if the URI is not identifying a file inside the repository.

encodeHashKey

String encodeHashKey(byte[] hashKey)

Encodes the hash key to string.

Parameters:

hashKey - the hash key identifying the file.

Returns:

a string version of the hashkey.

decodeHashKey

byte[] decodeHashKey(String hashKey)

Decodes the hash key from string.

Parameters:

hashKey - the hash key string.

Returns:

the hash key.