org.dspace.app.util

Class MetadataExposureServiceImpl

java.lang.Object

org.dspace.app.util.MetadataExposureServiceImpl

All Implemented Interfaces:

MetadataExposureService

public class MetadataExposureServiceImpl
extends Object
implements MetadataExposureService

Static utility class to manage configuration for exposure (hiding) of certain Item metadata fields. This class answers the question, "is the user allowed to see this metadata field?" Any external interface (UI, OAI-PMH, etc) that disseminates metadata should consult it before disseminating the value of a metadata field. Since the MetadataExposure.isHidden() method gets called in a lot of inner loops, it is important to implement it efficiently, in both time and memory utilization. It computes an answer without consuming ANY memory (e.g. it does not build any temporary Strings) and in close to constant time by use of hash tables. Although most sites will only hide a few fields, we can't predict what the usage will be so it's better to make it scalable. Algorithm is as follows: 1. If a Context is provided and it has a user who is Administrator, always grant access (return false). 2. Return true if field is on the hidden list, false otherwise. The internal maps are populated from DSpace Configuration at the first call, in case the properties are not available in the static context. Configuration Properties: ## hide a single metadata field #metadata.hide.SCHEMA.ELEMENT[.QUALIFIER] = true # example: dc.type metadata.hide.dc.type = true # example: dc.description.provenance metadata.hide.dc.description.provenance = true

Version:

$Revision: 3734 $

Author:

Larry Stone

Field Summary

Fields

Modifier and Type	Field and Description
protected AuthorizeService	authorizeService
protected String	CONFIG_PREFIX
protected Map<String,Map<String,Set<String>>>	hiddenElementMaps
protected Map<String,Set<String>>	hiddenElementSets
protected org.apache.log4j.Logger	log

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	MetadataExposureServiceImpl()

Method Summary

Modifier and Type	Method and Description
protected void	init() Loads maps from configuration unless it's already done.
boolean	isHidden(Context context, String schema, String element, String qualifier) Returns whether the given metadata field should be exposed (visible).
protected boolean	isInitialized() Returns whether the maps from configuration have already been loaded into the hiddenElementSets property.

Methods inherited from class java.lang.Object

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

Field Detail

log

protected org.apache.log4j.Logger log

hiddenElementSets

protected Map<String,Set<String>> hiddenElementSets

hiddenElementMaps

protected Map<String,Map<String,Set<String>>> hiddenElementMaps

CONFIG_PREFIX

protected final String CONFIG_PREFIX

See Also:

Constant Field Values

authorizeService

@Autowired(required=true)
protected AuthorizeService authorizeService

Constructor Detail

MetadataExposureServiceImpl

protected MetadataExposureServiceImpl()

Method Detail

isHidden

public boolean isHidden(Context context,
                        String schema,
                        String element,
                        String qualifier)
                 throws SQLException

Description copied from interface: MetadataExposureService

Returns whether the given metadata field should be exposed (visible). The metadata field is in the DSpace's DC notation: schema.element.qualifier

Specified by:

isHidden in interface MetadataExposureService

Parameters:

context - DSpace context

schema - metadata field schema (namespace), e.g. "dc"

element - metadata field element

qualifier - metadata field qualifier

Returns:

true (hidden) or false (exposed)

Throws:

SQLException - if database error

isInitialized

protected boolean isInitialized()

Returns whether the maps from configuration have already been loaded into the hiddenElementSets property.

Returns:

true (initialized) or false (not initialized)

init

protected void init()

Loads maps from configuration unless it's already done. The configuration properties are a map starting with the "metadata.hide." prefix followed by schema, element and qualifier separated by dots and the value is true (hidden) or false (exposed).