# Class ISOMetadata

Object
AbstractMetadata
ModifiableMetadata
ISOMetadata

All Implemented Interfaces:
  `Serializable, Emptiable, LenientComparable, IdentifiedObject`

Direct Known Subclasses:
  `AbstractContentInformation, AbstractElement, AbstractGeographicExtent, AbstractGeolocationInformation, AbstractIdentification, AbstractParty, AbstractResult, AbstractSpatialRepresentation, DefaultAcquisitionInformation, DefaultAddress, DefaultAlgorithm, DefaultApplicationSchemaInformation, DefaultAssociatedResource, DefaultAttributeGroup, DefaultBasicMeasure, DefaultBrowseGraphic, DefaultCitation, DefaultCitationDate, DefaultConstraints, DefaultContact, DefaultCoupledResource, DefaultDataFile, DefaultDataQuality, DefaultDigitalTransferOptions, DefaultDimension, DefaultDistribution, DefaultDistributor, DefaultEnvironmentalRecord, DefaultEvaluationMethod, DefaultEvaluationReportInformation, DefaultEvent, DefaultExtendedElementInformation, DefaultExtent, DefaultFeatureTypeInfo, DefaultFormat, DefaultGCP, DefaultGeometricObjects, DefaultIdentifier, DefaultInstrument, DefaultKeywordClass, DefaultKeywords, DefaultLineage, DefaultMaintenanceInformation, DefaultMeasureDescription, DefaultMeasureReference, DefaultMedium, DefaultMetadata, DefaultMetadataExtensionInformation, DefaultMetadataScope, DefaultNominalResolution, DefaultObjective, DefaultOnlineResource, DefaultOperation, DefaultOperationChainMetadata, DefaultOperationMetadata, DefaultPlan, DefaultPlatform, DefaultPlatformPass, DefaultPortrayalCatalogueReference, DefaultProcessing, DefaultProcessStep, DefaultProcessStepReport, DefaultQualityMeasure, DefaultRangeDimension, DefaultRangeElementDescription, DefaultReleasability, DefaultRequestedDate, DefaultRequirement, DefaultResolution, DefaultResponsibility, DefaultScope, DefaultScopeDescription, DefaultSeries, DefaultSource, DefaultSourceReference, DefaultStandardOrderProcess, DefaultTelephone, DefaultTemporalExtent, DefaultUsage, DefaultVerticalExtent`

public class ISOMetadata extends ModifiableMetadata implements IdentifiedObject, Serializable
The base class of ISO 19115 implementation classes. Each sub-classes implements one of the ISO Metadata interface provided by GeoAPI.

## Limitations

- Instances of this class are not synchronized for multi-threading. Synchronization, if needed, is caller's responsibility.
- Serialized objects of this class are not guaranteed to be compatible with future Apache SIS releases. Serialization support is appropriate for short term storage or RMI between applications running the same version of Apache SIS. For long term storage, use `XML` instead.

Since:
  0.3
See Also:
  - Serialized Form

- ## Nested Class Summary

  ### Nested classes/interfaces inherited from class ModifiableMetadata

  `ModifiableMetadata​.State`

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `protected Collection<Identifier>`
  `identifiers`
  All identifiers associated with this metadata, or `null` if none.

- ## Constructor Summary

  Constructors
  Modifier
  Constructor
  Description
  `protected`
  `ISOMetadata()`
  Constructs an initially empty metadata.
  `protected`
  `ISOMetadata(Object object)`
  Constructs a new metadata initialized with the values from the specified object.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `protected Identifier`
  `getIdentifier()`
  Returns the first identifier which is presumed to be defined by ISO 19115 conceptual model.
  `IdentifierMap`
  `getIdentifierMap()`
  A map view of the identifiers collection as (authority, code) entries.
  `Collection<Identifier>`
  `getIdentifiers()`
  Returns all identifiers associated to this object (from conceptual model and from XML document).
  `MetadataStandard`
  `getStandard()`
  Returns the metadata standard implemented by subclasses, which is ISO 19115.
  `protected void`
  `setIdentifier(Identifier newValue)`
  Sets the identifier for metadata objects that are expected to contain at most one ISO 19115 identifier.

  ### Methods inherited from class ModifiableMetadata

  `checkWritePermission, copyCollection, copyList, copyMap, copySet, deepCopy, nonNullCollection, nonNullList, nonNullMap, nonNullSet, singleton, state, writeCollection, writeList, writeMap, writeSet`

  ### Methods inherited from class AbstractMetadata

  `asMap, asTreeTable, clone, equals, equals, getInterface, hashCode, isEmpty, nilReasons, prune, toString`

  ### Methods inherited from class Object

  `finalize, getClass, notify, notifyAll, wait, wait, wait`

- ## Field Details

  - ### identifiers

    protected Collection<Identifier> identifiers
    All identifiers associated with this metadata, or `null` if none. This field is initialized to a non-null value when first needed.

- ## Constructor Details

  - ### ISOMetadata

    protected ISOMetadata()
    Constructs an initially empty metadata.

  - ### ISOMetadata

    protected ISOMetadata(Object object)
    Constructs a new metadata initialized with the values from the specified object. If the given object is an instance of `IdentifiedObject`, then this constructor copies the collection of identifiers.
    Parameters:
      `object` - the metadata to copy values from, or `null` if none.

- ## Method Details

  - ### getStandard

    public MetadataStandard getStandard()
    Returns the metadata standard implemented by subclasses, which is ISO 19115.

    #### Note for implementers

    Subclasses shall not override this method in a way that depends on the object state, since this method may be indirectly invoked by copy constructors (i.e. is may be invoked before this metadata object is fully constructed).
    Specified by:
      `getStandard` in class `AbstractMetadata`
    Returns:
      the metadata standard, which is ISO 19115 by default.

  - ### getIdentifiers

    public Collection<Identifier> getIdentifiers()
    Returns all identifiers associated to this object (from conceptual model and from XML document). This collection may contain identifiers from different sources:
    - Identifiers specified in the ISO 19115-1 or 19115-2 abstract models, typically (but not necessarily) as an `identifier` property (may also be `metadataIdentifier`, `ISBN` or `ISSN` properties).
    - Identifiers specified in the ISO 19115-3 or 19115-4 XML schemas. Those identifiers are typically stored as a result of unmarshalling an XML document. Those identifiers can be recognized by an authority sets as one of the `IdentifierSpace` constants.
    Specified by:
      `getIdentifiers` in interface `IdentifiedObject`
    Returns:
      all identifiers associated to this object, or an empty collection if none.
    See Also:
      - `DefaultCitation​.getIdentifiers()`
      - `DefaultObjective​.getIdentifiers()`
      - `AbstractIdentifiedObject​.getIdentifiers()`

  - ### getIdentifierMap

    public IdentifierMap getIdentifierMap()
    A map view of the identifiers collection as (authority, code) entries. Each map entry is associated to an element from the above identifier collection in which the key is the identifier authority and the value is the identifier code.

    There is usually a one-to-one relationship between the map entries and the identifier elements, but not always:

    - The map view may contain less entries, because the map interface allows only one entry per authority. If the identifier collection contains many identifiers for the same authority, then only the first occurrence is visible through this `Map` view.
    - The map view may also contain more entries than the identifier collection. For example, the `Citation` interface defines separated attributes for ISBN, ISSN and other identifiers. This map view may choose to unify all those attributes in a single view.
    The map supports `put` operations if and only if this `IdentifiedObject` is modifiable.

    The default implementation returns a wrapper around the `identifiers` list. That map is live: changes in the identifiers list will be reflected in the map, and conversely.

    Specified by:
      `getIdentifierMap` in interface `IdentifiedObject`
    Returns:
      the identifiers as a map of (authority, code) entries, or an empty map if none.

  - ### getIdentifier

    protected Identifier getIdentifier()
    Returns the first identifier which is presumed to be defined by ISO 19115 conceptual model. This method checks the authority for filtering ignorable identifiers like ISBN/ISSN codes and XML attributes. This convenience method is provided for implementation of public `getIdentifier(Identifier)` methods in subclasses having an `identifier` property with [0 … 1] multiplicity.
    Returns:
      an identifier from ISO 19115-3 conceptual model (excluding XML identifiers), or `null` if none.
    Since:
      1.0

  - ### setIdentifier

    protected void setIdentifier(Identifier newValue)
    Sets the identifier for metadata objects that are expected to contain at most one ISO 19115 identifier. This convenience method is provided for implementation of public `setIdentifier(Identifier)` methods in subclasses having an `identifier` property with [0 … 1] multiplicity. The default implementation removes all identifiers that would be returned by `getIdentifier()` before to add the given one in the `identifiers` collection.
    Parameters:
      `newValue` - the new identifier value, or `null` for removing the identifier.
    Since:
      1.0