# Class DefaultKeywords

Object
AbstractMetadata
ModifiableMetadata
ISOMetadata
DefaultKeywords

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

public class DefaultKeywords extends ISOMetadata implements Keywords
Keywords, their type and reference source. The following property is mandatory in a well-formed metadata according ISO 19115:
`MD_Keywords` `└─keyword……` Commonly used word(s) or formalised word(s) or phrase(s) used to describe the subject.

## 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 inherited from class ISOMetadata

  `identifiers`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `DefaultKeywords()`
  Constructs an initially empty keywords.
  `DefaultKeywords(CharSequence... keywords)`
  Creates keywords initialized to the given key word.
  `DefaultKeywords(Keywords object)`
  Constructs a new instance initialized with the values from the specified metadata object.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `static DefaultKeywords`
  `castOrCopy(Keywords object)`
  Returns a SIS metadata implementation with the values of the given arbitrary implementation.
  `DefaultKeywordClass`
  `getKeywordClass()`
  Returns the user-defined categorization of groups of keywords that extend or are orthogonal to the standardized keyword type codes.
  `Collection<InternationalString>`
  `getKeywords()`
  Returns commonly used word(s) or formalised word(s) or phrase(s) used to describe the subject.
  `Citation`
  `getThesaurusName()`
  Returns the name of the formally registered thesaurus or a similar authoritative source of keywords.
  `KeywordType`
  `getType()`
  Returns the subject matter used to group similar keywords.
  `void`
  `setKeywordClass(DefaultKeywordClass newValue)`
  Sets the user-defined categorization of groups of keywords.
  `void`
  `setKeywords(Collection<? extends InternationalString> newValues)`
  Sets commonly used word(s) or formalised word(s) or phrase(s) used to describe the subject.
  `void`
  `setThesaurusName(Citation newValue)`
  Sets the name of the formally registered thesaurus or a similar authoritative source of keywords.
  `void`
  `setType(KeywordType newValue)`
  Sets the subject matter used to group similar keywords.

  ### Methods inherited from class ISOMetadata

  `getIdentifier, getIdentifierMap, getIdentifiers, getStandard, setIdentifier`

  ### Methods inherited from class ModifiableMetadata

  `checkWritePermission, collectionType, 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`

- ## Constructor Details

  - ### DefaultKeywords

    public DefaultKeywords()
    Constructs an initially empty keywords.

  - ### DefaultKeywords

    public DefaultKeywords(CharSequence... keywords)
    Creates keywords initialized to the given key word.
    Parameters:
      `keywords` - commonly used words or formalised words or phrases used to describe the subject, or `null` if none.

  - ### DefaultKeywords

    public DefaultKeywords(Keywords object)
    Constructs a new instance initialized with the values from the specified metadata object. This is a shallow copy constructor, because the other metadata contained in the given object are not recursively copied.
    Parameters:
      `object` - the metadata to copy values from, or `null` if none.
    See Also:
      - `castOrCopy(Keywords)`

- ## Method Details

  - ### castOrCopy

    public static DefaultKeywords castOrCopy(Keywords object)
    Returns a SIS metadata implementation with the values of the given arbitrary implementation. This method performs the first applicable action in the following choices:
    - If the given object is `null`, then this method returns `null`.
    - Otherwise if the given object is already an instance of `DefaultKeywords`, then it is returned unchanged.
    - Otherwise a new `DefaultKeywords` instance is created using the copy constructor and returned. Note that this is a shallow copy operation, because the other metadata contained in the given object are not recursively copied.
    Parameters:
      `object` - the object to get as a SIS implementation, or `null` if none.
    Returns:
      a SIS implementation containing the values of the given object (may be the given object itself), or `null` if the argument was null.

  - ### getKeywords

    public Collection<InternationalString> getKeywords()
    Returns commonly used word(s) or formalised word(s) or phrase(s) used to describe the subject.
    Specified by:
      `getKeywords` in interface `Keywords`
    Returns:
      word(s) or phrase(s) used to describe the subject.

  - ### setKeywords

    public void setKeywords(Collection<? extends InternationalString> newValues)
    Sets commonly used word(s) or formalised word(s) or phrase(s) used to describe the subject.
    Parameters:
      `newValues` - the new keywords.

  - ### getType

    public KeywordType getType()
    Returns the subject matter used to group similar keywords.
    Specified by:
      `getType` in interface `Keywords`
    Returns:
      subject matter used to group similar keywords, or `null`.

  - ### setType

    public void setType(KeywordType newValue)
    Sets the subject matter used to group similar keywords.
    Parameters:
      `newValue` - the new keyword type.

  - ### getThesaurusName

    public Citation getThesaurusName()
    Returns the name of the formally registered thesaurus or a similar authoritative source of keywords.
    Specified by:
      `getThesaurusName` in interface `Keywords`
    Returns:
      name of registered thesaurus or similar authoritative source of keywords, or `null`.

  - ### setThesaurusName

    public void setThesaurusName(Citation newValue)
    Sets the name of the formally registered thesaurus or a similar authoritative source of keywords.
    Parameters:
      `newValue` - the new thesaurus name.

  - ### getKeywordClass

    @UML(identifier="keywordClass", obligation=OPTIONAL, specification=ISO_19115) public DefaultKeywordClass getKeywordClass()
    Returns the user-defined categorization of groups of keywords that extend or are orthogonal to the standardized keyword type codes.
    Upcoming API change — generalization
    The element type will be changed to the `KeywordClass` interface when GeoAPI will provide it (tentatively in GeoAPI 3.1).
    Returns:
      user-defined categorization of groups of keywords, or `null` if none.
    Since:
      0.5

  - ### setKeywordClass

    public void setKeywordClass(DefaultKeywordClass newValue)
    Sets the user-defined categorization of groups of keywords.
    Upcoming API change — generalization
    The argument type will be changed to the `KeywordClass` interface when GeoAPI will provide it (tentatively in GeoAPI 3.1).
    Parameters:
      `newValue` - new user-defined categorization of groups of keywords.
    Since:
      0.5