Package io.permazen.encoding

Class DefaultEncodingRegistry

java.lang.Object

io.permazen.encoding.SimpleEncodingRegistry

io.permazen.encoding.DefaultEncodingRegistry

All Implemented Interfaces:

EncodingRegistry

public class DefaultEncodingRegistry
extends SimpleEncodingRegistry

Permazen's default EncodingRegistry.

Instances automatically register all of Permazen's built-in Encodings (see below).

Array Types

Because this class is a subclass of SimpleEncodingRegistry, encodings for array types are created on demand, so they don't need to be explicitly registered.

Enum Types

Encodings for Enum types are not registered in an EncodingRegistry. Instead, Enum values are represented as EnumValue instances, and Enum fields are specially defined in the schema with an explicit identifier list. In turn, EnumValue's are encoded by EnumValueEncoding.

Custom Encodings

During construction, instances scan the class path for custom EncodingRegistry implementations and will delegate to them when an encoding is not found.

If multiple custom EncodingRegistry implementations advertise the same encoding, one will be chosen arbitrarily.

Custom EncodingRegistry implemenations are specified via META-INF/services/io.permazen.encoding.EncodingRegistry files or by module exports; see ServiceLoader. Custom implementations are only queried for non-array types.

Built-in Encodings

Permazen provides built-in Encodings covering the following Java types:

• Primitive types (boolean, int, etc.)
• Primitive array types (boolean, int, etc.)
• Primitive wrapper types (Boolean, Integer, etc.)
• String
• BigDecimal
• BigInteger
• BitSet
• Date
• UUID
• URI
• File
• InetAddress
• Inet4Address
• Inet6Address
• Pattern
• java.time.*
• InternetAddress (if present on the classpath)

Field Summary

Fields

Modifier and Type	Field	Description
protected final ArrayList<EncodingRegistry>	customEncodingRegistries

Fields inherited from class io.permazen.encoding.SimpleEncodingRegistry

log

Constructor Summary

Constructors

Constructor	Description
DefaultEncodingRegistry()	Constructor.

Method Summary

Modifier and Type	Method	Description
protected void	addBuiltinEncodings()	Register Permazen's built-in encodings.
protected void	addOptionalBuiltinEncoding(String name, Function<EncodingId,? extends Encoding<?>> builder)	Register a built-in encoding, but only if its target class is found on the classpath.
protected void	addOptionalBuiltinEncodings()	Register Permazen's optional built-in encodings.
protected void	addStandardBuiltinEncodings()	Register Permazen's standard built-in encodings.
String	aliasForId(EncodingId encodingId)	Get the alias (or "nickname") for the given encoding ID in this registry, if any.
protected void	findCustomEncodingRegistries()	Scan the class path (via ServiceLoader and the current thread's context class loader) for custom EncodingRegistry implementations
Encoding<?>	getEncoding(EncodingId encodingId)	Get the Encoding with the given encoding ID in this registry.
<T> List<Encoding<T>>	getEncodings(TypeToken<T> typeToken)	Get all of the Encodings in this registry that supports values of the given Java type.
EncodingId	idForAlias(String alias)	Get the encoding ID corresponding to the given alias (or "nickname"), if any.
protected void	initialize()	Initialize this instance.

Methods inherited from class io.permazen.encoding.SimpleEncodingRegistry

add, buildArrayEncoding, register

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.permazen.encoding.EncodingRegistry

getEncoding

Field Details

customEncodingRegistries

protected final ArrayList<EncodingRegistry> customEncodingRegistries

Constructor Details

DefaultEncodingRegistry

public DefaultEncodingRegistry()

Constructor.

This constructor invokes initialize().

Method Details

idForAlias

public EncodingId idForAlias(String alias)

Description copied from interface: EncodingRegistry

Get the encoding ID corresponding to the given alias (or "nickname"), if any.

See aliasForId() for details on aliases.

If alias is a valid alias, this method should return the corresponding EncodingId. If alias is not a valid alias, but is a valid encoding ID in string form, this method should return the corresponding EncodingId as if by new EncodingId(alias). Otherwise, this method should throw IllegalArgumentException.

Note: the EncodingId corresponding to an alias does not need to be actually registered with this instance in order for the alias to be valid.

The implementation in EncodingRegistry just invokes new EncodingId(alias).

Parameters:

alias - encoding ID alias

Returns:

corresponding encoding ID, never null

aliasForId

public String aliasForId(EncodingId encodingId)

Description copied from interface: EncodingRegistry

Get the alias (or "nickname") for the given encoding ID in this registry, if any.

An EncodingRegistry may support aliases for some of its encoding ID's. Aliases are simply more friendly names for EncodingId strings, which are formatted as Uniform Resource Names (URNs).

Whereas EncodingId's are globally unique, aliases are only meaningful to the particular EncodingRegistry instance being queried. When a schema is recorded in a database, actual EncodingId's are always used.

In Permazen's DefaultEncodingRegistry, the built-in encodings all have aliases; for example, "int" is an alias for "urn:fdc:permazen.io:2020:int". Permazen's aliases are available via EncodingIds.aliasForId() and EncodingIds#idForAlias().

If no alias is known for encodingId, this method should return EncodingId.getId().

Note: an EncodingId does not need to be actually registered with this instance in order for it to have an alias.

The implementation in EncodingRegistry always returns EncodingId.getId().

Parameters:

encodingId - encoding ID

Returns:

corresponding alias, if any, otherwise EncodingId.getId()

See Also:

• EncodingRegistry.idForAlias(java.lang.String)

getEncoding

public Encoding<?> getEncoding(EncodingId encodingId)

Description copied from interface: EncodingRegistry

Get the Encoding with the given encoding ID in this registry.

Specified by:

getEncoding in interface EncodingRegistry

Overrides:

getEncoding in class SimpleEncodingRegistry

Parameters:

encodingId - encoding ID

Returns:

corresponding Encoding, if any, otherwise null

getEncodings

public <T> List<Encoding<T>> getEncodings(TypeToken<T> typeToken)

Description copied from interface: EncodingRegistry

Get all of the Encodings in this registry that supports values of the given Java type.

The Java type must exactly match the Encoding's supported Java type.

Specified by:

getEncodings in interface EncodingRegistry

Overrides:

getEncodings in class SimpleEncodingRegistry

Type Parameters:

T - field value type

Parameters:

typeToken - field value type

Returns:

unmodifiable list of Encodings supporting Java values of type typeToken, possibly empty

initialize

protected void initialize()

Initialize this instance.

This method is invoked by the default constructor. The implementation in DefaultEncodingRegistry invokes addBuiltinEncodings() and then findCustomEncodingRegistries().

addBuiltinEncodings

protected void addBuiltinEncodings()

Register Permazen's built-in encodings.

The implementation in DefaultEncodingRegistry invokes addStandardBuiltinEncodings() and then addOptionalBuiltinEncodings().

addStandardBuiltinEncodings

protected void addStandardBuiltinEncodings()

Register Permazen's standard built-in encodings.

addOptionalBuiltinEncodings

protected void addOptionalBuiltinEncodings()

Register Permazen's optional built-in encodings.

The optional built-in encodings are ones that depend on optional dependencies. An example is InternetAddressEncoding which depends on the Jakarta Mail API.

addOptionalBuiltinEncoding

protected void addOptionalBuiltinEncoding(String name,
 Function<EncodingId,? extends Encoding<?>> builder)

Register a built-in encoding, but only if its target class is found on the classpath.

The implementation in DefaultEncodingRegistry invokes the given builder but will catch and ignore any NoClassDefFoundError thrown. Otherwise, the encoding is registered.

No attempt to initialize the encoding class should have occurred prior to invoking this method.

Parameters:

name - builtin encoding ID suffix

builder - builder for encoding

findCustomEncodingRegistries

protected void findCustomEncodingRegistries()

Scan the class path (via ServiceLoader and the current thread's context class loader) for custom EncodingRegistry implementations