Package org.apache.sis.util.iso

# Class DefaultRecordType

Object
DefaultRecordType

All Implemented Interfaces:
  `Serializable`, `RecordType`, `Type`

public class DefaultRecordType extends Object implements RecordType, Serializable
An immutable definition of the type of a record. A `RecordType` is identified by a type name and contains an arbitrary amount of members (fields) as (name, type) pairs. A `RecordType` may therefore contain another `RecordType` as a field.
Comparison with Java reflection: `RecordType` instances can be though as equivalent to instances of the Java `Class` class. The set of fields in a `RecordType` can be though as equivalent to the set of fields in a class.

## Instantiation

The easiest way to create `DefaultRecordType` instances is to use the `DefaultRecordSchema​.createRecordType(CharSequence, Map)` method. Example:

>     DefaultRecordSchema schema = new DefaultRecordSchema(null, null, "MySchema");
>     // The same instance can be reused for all records to create in that schema.

>     Map<CharSequence,Class<?>> fields = new LinkedHashMap<>();
>     fields.put("city",        String .class);
>     fields.put("latitude",    Double .class);
>     fields.put("longitude",   Double .class);
>     fields.put("population",  Integer.class);
>     RecordType record = schema.createRecordType("MyRecordType", fields);

## Immutability and thread safety

This class is immutable and thus inherently thread-safe if the `TypeName`, the `RecordSchema` and all (`MemberName`, `Type`) entries in the map given to the constructor are also immutable. Subclasses shall make sure that any overridden methods remain safe to call from multiple threads and do not change any public `RecordType` state.

## Serialization

This class is serializable if all elements given to the constructor are also serializable. Note in particular that `DefaultRecordSchema` is currently not serializable, so users wanting serialization may need to provide their own schema.

Since:
  0.3
See Also:
  - `DefaultRecord`
  - `DefaultRecordSchema`
  - `DefaultMemberName`
  - Serialized Form

Defined in the `sis-metadata` module

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `DefaultRecordType(RecordType other)`
  Creates a new record with the same names and fields than the given one.
  `DefaultRecordType(TypeName typeName, RecordSchema container, Map<? extends MemberName,? extends Type> fields)`
  Creates a new record in the given schema.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `static DefaultRecordType`
  `castOrCopy(RecordType other)`
  Returns a SIS implementation with the name and fields of the given arbitrary implementation.
  `boolean`
  `equals(Object other)`
  Compares the given object with this `RecordType` for equality.
  `RecordSchema`
  `getContainer()`
  Deprecated.
  The `RecordSchema` interface has been removed in the 2015 revision of ISO 19103 standard.
  `Map<MemberName,Type>`
  `getFieldTypes()`
  Returns the dictionary of all (name, type) pairs in this record type.
  `Set<MemberName>`
  `getMembers()`
  Returns the set of attribute names defined in this `RecordType`'s dictionary.
  `Map<MemberName,Type>`
  `getMemberTypes()`
  Deprecated.
  Renamed `getFieldTypes()` for consistency with the 2015 revision of ISO 19103 standard.
  `TypeName`
  `getTypeName()`
  Returns the name that identifies this record type.
  `int`
  `hashCode()`
  Returns a hash code value for this `RecordType`.
  `boolean`
  `isInstance(Record record)`
  Determines if the given record is compatible with this record type.
  `TypeName`
  `locate(MemberName fieldName)`
  Returns the type associated to the given attribute name, or `null` if none.
  `String`
  `toString()`
  Returns a string representation of this object.

  ### Methods inherited from class Object

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

- ## Constructor Details

  - ### DefaultRecordType

    public DefaultRecordType(RecordType other)
    Creates a new record with the same names and fields than the given one.
    Parameters:
      `other` - the `RecordType` to copy.

  - ### DefaultRecordType

    public DefaultRecordType(TypeName typeName, RecordSchema container, Map<? extends MemberName,? extends Type> fields)
    Creates a new record in the given schema. It is caller responsibility to add the new `RecordType` in the container description map, if desired.

    This constructor is provided mostly for developers who want to create `DefaultRecordType` instances in their own `RecordSchema` implementation. Otherwise if the default record schema implementation is sufficient, the `DefaultRecordSchema​.createRecordType(CharSequence, Map)` method provides an easier alternative.

    Parameters:
      `typeName` - the name that identifies this record type.
      `container` - the schema that contains this record type.
      `fields` - the name and type of the fields to be included in this record type.
    See Also:
      - `DefaultRecordSchema​.createRecordType(CharSequence, Map)`

- ## Method Details

  - ### castOrCopy

    public static DefaultRecordType castOrCopy(RecordType other)
    Returns a SIS implementation with the name and fields 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 `DefaultRecordType`, then it is returned unchanged.
    - Otherwise a new `DefaultRecordType` instance is created using the copy constructor and returned. Note that this is a shallow copy operation, since the fields contained in the given object are not recursively copied.
    Parameters:
      `other` - the object to get as a SIS implementation, or `null` if none.
    Returns:
      a SIS implementation containing the fields of the given object (may be the given object itself), or `null` if the argument was `null`.

  - ### getTypeName

    public TypeName getTypeName()
    Returns the name that identifies this record type. If this `RecordType` is contained in a record schema, then the record type name shall be valid in the name space of the record schema:

    >     NameSpace namespace = getContainer().getSchemaName().scope()

    Comparison with Java reflection: If we think about this `RecordType` as equivalent to a `Class` instance, then this method can be think as the equivalent of the Java `Class​.getName()` method.
    Specified by:
      `getTypeName` in interface `RecordType`
    Specified by:
      `getTypeName` in interface `Type`
    Returns:
      the name that identifies this record type.

  - ### getContainer

    @Deprecated public RecordSchema getContainer()
    Deprecated.
    The `RecordSchema` interface has been removed in the 2015 revision of ISO 19103 standard.
    Returns the schema that contains this record type.
    Specified by:
      `getContainer` in interface `RecordType`
    Returns:
      the schema that contains this record type.

  - ### getMemberTypes

    @Deprecated public Map<MemberName,Type> getMemberTypes()
    Deprecated.
    Renamed `getFieldTypes()` for consistency with the 2015 revision of ISO 19103 standard.
    Returns the dictionary of all (name, type) pairs in this record type. The returned map is unmodifiable.
    Comparison with Java reflection: If we think about this `RecordType` as equivalent to a `Class` instance, then this method can be though as the related to the Java `Class​.getFields()` method.
    Specified by:
      `getMemberTypes` in interface `RecordType`
    Returns:
      the dictionary of (name, type) pairs, or an empty map if none.

  - ### getFieldTypes

    public Map<MemberName,Type> getFieldTypes()
    Returns the dictionary of all (name, type) pairs in this record type. The returned map is unmodifiable.
    Comparison with Java reflection: If we think about this `RecordType` as equivalent to a `Class` instance, then this method can be though as the related to the Java `Class​.getFields()` method.
    Returns:
      the dictionary of (name, type) pairs, or an empty map if none.
    Since:
      1.1

  - ### getMembers

    public Set<MemberName> getMembers()
    Returns the set of attribute names defined in this `RecordType`'s dictionary. This method is functionally equivalent to the following code, but slightly more efficient:

    >     getFieldTypes().keySet();

    Specified by:
      `getMembers` in interface `RecordType`
    Returns:
      the set of field names, or an empty set if none.

  - ### locate

    public TypeName locate(MemberName fieldName)
    Returns the type associated to the given attribute name, or `null` if none. This method is functionally equivalent to (omitting the check for null value):

    >     getFieldTypes().get(name).getTypeName();

    Comparison with Java reflection: If we think about this `RecordType` as equivalent to a `Class` instance, then this method can be though as related to the Java `Class​.getField(String)` method.
    Specified by:
      `locate` in interface `RecordType`
    Parameters:
      `fieldName` - the attribute name for which to get the associated type name.
    Returns:
      the associated type name, or `null` if none.

  - ### isInstance

    public boolean isInstance(Record record)
    Determines if the given record is compatible with this record type. This method returns `true` if the given `record` argument is non-null and the following condition holds:

    >     Set<MemberName> attributeNames = record.getAttributes().keySet();
    >     boolean isInstance = getMembers().containsAll(attributeNames);

    Implementation note: We do not require that `record​.getRecordType() == this` in order to allow record "sub-types" to define additional fields, in a way similar to Java sub-classing.
    Specified by:
      `isInstance` in interface `RecordType`
    Parameters:
      `record` - the record to test for compatibility.
    Returns:
      `true` if the given record is compatible with this `RecordType`.

  - ### equals

    public boolean equals(Object other)
    Compares the given object with this `RecordType` for equality.
    Overrides:
      `equals` in class `Object`
    Parameters:
      `other` - the object to compare with this `RecordType`.
    Returns:
      `true` if both objects are equal.

  - ### hashCode

    public int hashCode()
    Returns a hash code value for this `RecordType`.
    Overrides:
      `hashCode` in class `Object`

  - ### toString

    public String toString()
    Returns a string representation of this object. The string representation is for debugging purpose and may change in any future SIS version.
    Overrides:
      `toString` in class `Object`
    Returns:
      a string representation of this record type.