Package eu.europa.esig.dss.tsl.sha2

Class Sha2FileCacheDataLoader

java.lang.Object

eu.europa.esig.dss.tsl.sha2.Sha2FileCacheDataLoader

All Implemented Interfaces:

DSSCacheFileLoader, DSSFileLoader, Serializable

public class Sha2FileCacheDataLoader
extends Object
implements DSSCacheFileLoader

This class implements a document loading logic, defined within ETSI TS 119 612 "6.1 TL publication" for Trusted Lists. The class will try to access a corresponding .sha2 file for every requested document available in the cache, compare its digest, and will enforce a document update if the document has expired. The class provides constructors allowing manual configuration of the object, as well as static methods allowing to instantiate pre-configured objects for Trusted Lists validation. See: - #initSha2StrictDataLoader method to create a dataloader, enforcing refresh of a Trusted List only when a new .sha2 document is obtained or NextUpdate has been reached; - #initSha2DailyUpdateDataLoader method to create a dataloader, enforcing refresh of a Trusted List when a new .sha2 document is obtained, NextUpdate has been reached or when the document has not been updated for at least 24 hours; - #initSha2CustomExpirationDataLoader method to create a dataloader, enforcing refresh of a Trusted List when a new .sha2 document is obtained, NextUpdate has been reached or when the document has not been updated for the indicated time period; - #initSha2IgnoredDataLoader method to create a dataloader, enforcing refresh of a Trusted List in all cases.

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
Sha2FileCacheDataLoader()	Creates an object with an empty configuration (shall be provided with a setter)
Sha2FileCacheDataLoader(DSSCacheFileLoader dataLoader)	Creates an object with a defined DSSCacheFileLoader.

Method Summary

Modifier and Type	Method	Description
protected void	assertConfigurationIsValid()	This method verifies whether the configuration of the class is complete to proceed with execution
protected void	assertExtensionIsSupported(String fileExtension)	This method verifies whether the remote document's fileExtension is supported by the implementation.
protected boolean	checkRefreshRequired(DocumentWithSha2 documentWithSha2)	This method checks whether the cached document should be refreshed
DSSCacheFileLoader	getDataLoader()	Returns the file cache data loader used to load the documents
DSSDocument	getDocument(String url)	Returns DSSDocument from the provided url
DSSDocument	getDocument(String url, boolean refresh)	This method allows to download a DSSDocument from a specified url with a custom setting indicating whether the refresh of the document's cache shall be enforced, when applicable
DSSDocument	getDocumentFromCache(String url)	Allows to load a document for a given url from the cache folder.
protected DSSDocument	getRefreshedDocument(String documentUrl)	This method returns a document from cache, when applicable.
protected DSSDocument	getSha2File(String documentUrl)	This method returns a sha2 file for the given documentUrl.
protected String	getSha2FileUrl(String documentUrl)	Method transforms a given documentUrl to a corresponding URL location containing a sha2 document
static Sha2FileCacheDataLoader	initSha2CustomExpirationDataLoader(DSSCacheFileLoader dataLoader, long cacheExpirationTime)	This method instantiates a Sha2FileCacheDataLoader with a pre-configured predicate, forcing a Trusted List refresh in case of an updated .sha2 document, when a NextUpdate has been reached, or when the cached document expired according to the provided cacheExpirationTime value.
static Sha2FileCacheDataLoader	initSha2DailyUpdateDataLoader(DSSCacheFileLoader dataLoader)	This method instantiates a Sha2FileCacheDataLoader with a pre-configured predicate, forcing a Trusted List refresh in case of an updated .sha2 document, when a NextUpdate has been reached, or when the document has not been re-downloaded for at least a day.
static Sha2FileCacheDataLoader	initSha2IgnoredDataLoader(DSSCacheFileLoader dataLoader)	This method instantiates a Sha2FileCacheDataLoader with a pre-configured predicate, forcing a Trusted List refresh in all cases despite the .sha2 file document content.
static Sha2FileCacheDataLoader	initSha2StrictDataLoader(DSSCacheFileLoader dataLoader)	This method instantiates a Sha2FileCacheDataLoader with a pre-configured predicate, forcing a Trusted List refresh in case of an updated .sha2 document, or when a NextUpdate has been reached.
protected DocumentWithSha2	mergeDocumentWithSha2(DSSDocument cachedDocument, DSSDocument sha2Document)	This class creates a eu.europa.esig.dss.tsl.sha2.DocumentWithSha2 object by merging a cachedDocument and sha2Document together
boolean	remove(String url)	Removes the file from cache with the given url
void	setDataLoader(DSSCacheFileLoader dataLoader)	Sets the file cache data loader to be used to load the documents
void	setPredicate(Predicate<DocumentWithSha2> predicate)	This method sets a predicate evaluating a condition for a document to be refreshed.

Methods inherited from class java.lang.Object

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

Constructor Details

Sha2FileCacheDataLoader

public Sha2FileCacheDataLoader()

Creates an object with an empty configuration (shall be provided with a setter)

Sha2FileCacheDataLoader

public Sha2FileCacheDataLoader(DSSCacheFileLoader dataLoader)

Creates an object with a defined DSSCacheFileLoader. The predicate shall be provided with a setter.

Parameters:

dataLoader - DSSCacheFileLoader to use

Method Details

initSha2StrictDataLoader

public static Sha2FileCacheDataLoader initSha2StrictDataLoader(DSSCacheFileLoader dataLoader)

This method instantiates a Sha2FileCacheDataLoader with a pre-configured predicate, forcing a Trusted List refresh in case of an updated .sha2 document, or when a NextUpdate has been reached. The created object does not enforce refresh after a specific time period.

Parameters:

dataLoader - DSSCacheFileLoader to be used to load the document

Returns:

Sha2FileCacheDataLoader

initSha2DailyUpdateDataLoader

public static Sha2FileCacheDataLoader initSha2DailyUpdateDataLoader(DSSCacheFileLoader dataLoader)

This method instantiates a Sha2FileCacheDataLoader with a pre-configured predicate, forcing a Trusted List refresh in case of an updated .sha2 document, when a NextUpdate has been reached, or when the document has not been re-downloaded for at least a day.

Parameters:

dataLoader - DSSCacheFileLoader to be used to load the document

Returns:

Sha2FileCacheDataLoader

initSha2CustomExpirationDataLoader

public static Sha2FileCacheDataLoader initSha2CustomExpirationDataLoader(DSSCacheFileLoader dataLoader,
 long cacheExpirationTime)

This method instantiates a Sha2FileCacheDataLoader with a pre-configured predicate, forcing a Trusted List refresh in case of an updated .sha2 document, when a NextUpdate has been reached, or when the cached document expired according to the provided cacheExpirationTime value.

Parameters:

dataLoader - DSSCacheFileLoader to be used to load the document

cacheExpirationTime - value in milliseconds indicating a maximum time after which a document shall be re-downloaded

Returns:

Sha2FileCacheDataLoader

initSha2IgnoredDataLoader

public static Sha2FileCacheDataLoader initSha2IgnoredDataLoader(DSSCacheFileLoader dataLoader)

This method instantiates a Sha2FileCacheDataLoader with a pre-configured predicate, forcing a Trusted List refresh in all cases despite the .sha2 file document content.

Parameters:

dataLoader - DSSCacheFileLoader to be used to load the document

Returns:

Sha2FileCacheDataLoader

getDataLoader

public DSSCacheFileLoader getDataLoader()

Returns the file cache data loader used to load the documents

Returns:

DSSCacheFileLoader

setDataLoader

public void setDataLoader(DSSCacheFileLoader dataLoader)

Sets the file cache data loader to be used to load the documents

Parameters:

dataLoader - DSSCacheFileLoader

setPredicate

public void setPredicate(Predicate<DocumentWithSha2> predicate)

This method sets a predicate evaluating a condition for a document to be refreshed. The predicate returns TRUE when the condition is valid and no document refresh is required, FALSE otherwise

Parameters:

predicate - Predicate

getDocument

public DSSDocument getDocument(String url)
                        throws DSSException

Description copied from interface: DSSFileLoader

Returns DSSDocument from the provided url

Specified by:

getDocument in interface DSSFileLoader

Parameters:

url - String url of the document to obtain

Returns:

DSSDocument retrieved document

Throws:

DSSException - in case of DataLoader error

getDocument

public DSSDocument getDocument(String url,
 boolean refresh)

Description copied from interface: DSSCacheFileLoader

This method allows to download a DSSDocument from a specified url with a custom setting indicating whether the refresh of the document's cache shall be enforced, when applicable

Specified by:

getDocument in interface DSSCacheFileLoader

Parameters:

url - String remote location of the document to download

refresh - indicates whether the refresh of the cached document shall be enforced

Returns:

DSSDocument

getRefreshedDocument

protected DSSDocument getRefreshedDocument(String documentUrl)

This method returns a document from cache, when applicable. If no document is available in the cache, returns NULL.

Parameters:

documentUrl - String representing document's access point

Returns:

DSSDocument

getSha2File

protected DSSDocument getSha2File(String documentUrl)

This method returns a sha2 file for the given documentUrl. If not sha2 document found, returns NULL.

Parameters:

documentUrl - String URL of the document, for which to retrieve a sha2 file

Returns:

DSSDocument representing a sha2 file

getSha2FileUrl

protected String getSha2FileUrl(String documentUrl)

Method transforms a given documentUrl to a corresponding URL location containing a sha2 document

Parameters:

documentUrl - String URL of the document to be retrieved

Returns:

String URL of the sha2 corresponding to the document to be retrieved

assertExtensionIsSupported

protected void assertExtensionIsSupported(String fileExtension)

This method verifies whether the remote document's fileExtension is supported by the implementation. The Trusted Lists distribution points shall end with ".xml" or ".xtsl" strings

Parameters:

fileExtension - String to check

mergeDocumentWithSha2

protected DocumentWithSha2 mergeDocumentWithSha2(DSSDocument cachedDocument,
 DSSDocument sha2Document)

This class creates a eu.europa.esig.dss.tsl.sha2.DocumentWithSha2 object by merging a cachedDocument and sha2Document together

Parameters:

cachedDocument - DSSDocument representing an original cached document

sha2Document - DSSDocument representing a sha2 document

Returns:

DocumentWithSha2

checkRefreshRequired

protected boolean checkRefreshRequired(DocumentWithSha2 documentWithSha2)

This method checks whether the cached document should be refreshed

Parameters:

documentWithSha2 - DocumentWithSha2 representing the original document with sha2 file content

Returns:

TRUE if the document shall be refreshed, FALSE otherwise

getDocumentFromCache

public DSSDocument getDocumentFromCache(String url)

Description copied from interface: DSSCacheFileLoader

Allows to load a document for a given url from the cache folder. If the document is not found in the cache, returns NULL.

Specified by:

getDocumentFromCache in interface DSSCacheFileLoader

Parameters:

url - String url of the file

Returns:

DSSDocument or NULL if the file does not exist

remove

public boolean remove(String url)

Description copied from interface: DSSCacheFileLoader

Removes the file from cache with the given url

Specified by:

remove in interface DSSCacheFileLoader

Specified by:

remove in interface DSSFileLoader

Parameters:

url - String url of the remote file location (the same what was used on file saving)

Returns:

TRUE when file was successfully deleted, FALSE otherwise

assertConfigurationIsValid

protected void assertConfigurationIsValid()

This method verifies whether the configuration of the class is complete to proceed with execution