Package com.stardog.stark.io.language

Class BCP47LanguageHandler

java.lang.Object

com.stardog.stark.io.language.BCP47LanguageHandler

All Implemented Interfaces:

LanguageHandler

public final class BCP47LanguageHandler
extends Object
implements LanguageHandler

A language handler that can verify BCP47 formatted language tags.

This language handler normalises language tags to lower-case if normalizeLanguage(String, String) is used.

Author:

Peter Ansell

See Also:

• BCP47

Field Summary

Fields inherited from interface com.stardog.stark.io.LanguageHandler

BCP47, RFC3066, RFC4646

Constructor Summary

Constructors

Constructor	Description
BCP47LanguageHandler()

Method Summary

Modifier and Type	Method	Description
boolean	isRecognizedLanguage(String theLang)	Checks if the given language tag is recognized by this language handler, including cases where the language tag is recognized, but is not yet normalized.
String	key()	A unique key for this language handler
Literal	normalizeLanguage(String theValue, String theLang)	Normalize both the language tag and the language if appropriate.
String	normalizeLanguageTag(String theLang)	Normalizes the given BCP47 language tag according to the rules defined by the JDK in the Locale API.
boolean	verifyLanguage(String theValue, String theLang)	Verifies that the language tag is valid, optionally including an automated check on the literal value.

Methods inherited from class java.lang.Object

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

Constructor Details

BCP47LanguageHandler

public BCP47LanguageHandler()

Method Details

isRecognizedLanguage

public boolean isRecognizedLanguage(@Nonnull
 String theLang)

Checks if the given language tag is recognized by this language handler, including cases where the language tag is recognized, but is not yet normalized.

Specified by:

isRecognizedLanguage in interface LanguageHandler

Parameters:

theLang - The language tag to check.

Returns:

True if the language tag is syntactically valid and could be used with LanguageHandler.verifyLanguage(String, String) and LanguageHandler.normalizeLanguage(String, String).

verifyLanguage

public boolean verifyLanguage(@Nonnull
 String theValue,
 @Nonnull
 String theLang)
                       throws InvalidLiteral

Verifies that the language tag is valid, optionally including an automated check on the literal value.

This method must only be called after verifying that LanguageHandler.isRecognizedLanguage(String) returns true for the given language tag.

Specified by:

verifyLanguage in interface LanguageHandler

Parameters:

theValue - Literal value matching the given language tag.

theLang - A language tag that matched with LanguageHandler.isRecognizedLanguage(String).

Returns:

`true` if the language tag is recognized by this language handler, and it is verified to be syntactically valid.

Throws:

InvalidLiteral - If the language tag was not recognized.

normalizeLanguage

@Nonnull
public Literal normalizeLanguage(@Nonnull
 String theValue,
 @Nonnull
 String theLang)
                          throws InvalidLiteral

Normalize both the language tag and the language if appropriate.

This method must only be called after verifying that LanguageHandler.isRecognizedLanguage(String) returns true for the given language tag, and LanguageHandler.verifyLanguage(String, String) also returns true for the given language and literal value.

Specified by:

normalizeLanguage in interface LanguageHandler

Parameters:

theValue - Required literal value to use in the normalization process and to provide the value for the resulting literal.

theLang - The language tag which is to be normalized. This tag is available in normalized form from the result using Literal.lang().

Returns:

A Literal containing the normalized literal value and language tag.

Throws:

InvalidLiteral - If the language tag was not recognized or verified, or the literal value could not be normalized due to an error.

key

@Nonnull
public String key()

A unique key for this language handler

Specified by:

key in interface LanguageHandler

Returns:

A unique `String` key.

normalizeLanguageTag

public String normalizeLanguageTag(@Nonnull
 String theLang)
                            throws IllformedLocaleException

Normalizes the given BCP47 language tag according to the rules defined by the JDK in the Locale API.

Specified by:

normalizeLanguageTag in interface LanguageHandler

Parameters:

theLang - An unnormalized, valid, language tag

Returns:

A normalized version of the given language tag

Throws:

IllformedLocaleException - If the given language tag is ill-formed according to the rules specified in BCP47.