com.vaadin.data.util.converter

Class StringToEnumConverter

java.lang.Object

com.vaadin.data.util.converter.StringToEnumConverter

All Implemented Interfaces:

Converter<String,Enum>, Serializable

public class StringToEnumConverter
extends Object
implements Converter<String,Enum>

A converter that converts from String to an Enum and back.

Designed to provide nice human readable strings for Enum classes conforming to one of these patterns:

• The constants are named SOME_UPPERCASE_WORDS and there's no toString implementation.
• toString() always returns the same human readable string that is not the same as its name() value. Each constant in the enum type returns a distinct toString() value.

Will not necessarily work correctly for other cases.

Since:

7.4

Author:

Vaadin Ltd

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface com.vaadin.data.util.converter.Converter

Converter.ConversionException

Constructor Summary

Constructors

Constructor and Description
StringToEnumConverter()

Method Summary

Modifier and Type	Method and Description
Enum	convertToModel(String value, Class<? extends Enum> targetType, Locale locale) Converts the given value from target type to source type.
String	convertToPresentation(Enum value, Class<? extends String> targetType, Locale locale) Converts the given value from source type to target type.
static String	enumToString(Enum<?> value, Locale locale) Converts the given enum to a human readable string using the given locale
Class<Enum>	getModelType() The source type of the converter.
Class<String>	getPresentationType() The target type of the converter.
static <T extends Enum<T>> T	stringToEnum(String value, Class<T> enumType, Locale locale) Converts the given string to the given enum type using the given locale

Methods inherited from class java.lang.Object

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

Constructor Detail

StringToEnumConverter

public StringToEnumConverter()

Method Detail

convertToModel

public Enum convertToModel(String value,
                           Class<? extends Enum> targetType,
                           Locale locale)
                    throws Converter.ConversionException

Description copied from interface: Converter

Converts the given value from target type to source type.

A converter can optionally use locale to do the conversion.

A converter should in most cases be symmetric so chaining Converter.convertToPresentation(Object, Class, Locale) and Converter.convertToModel(Object, Class, Locale) should return the original value.

Specified by:

convertToModel in interface Converter<String,Enum>

Parameters:

value - The value to convert, compatible with the target type. Can be null

targetType - The requested type of the return value

locale - The locale to use for conversion. Can be null.

Returns:

The converted value compatible with the source type

Throws:

Converter.ConversionException - If the value could not be converted

stringToEnum

public static <T extends Enum<T>> T stringToEnum(String value,
                                                 Class<T> enumType,
                                                 Locale locale)
                                          throws Converter.ConversionException

Converts the given string to the given enum type using the given locale

Compatible with enumToString(Enum, Locale)

Parameters:

value - The string value to convert

enumType - The type of enum to create

locale - The locale to use for conversion. If null, the JVM default locale will be used

Returns:

The enum which matches the given string

Throws:

ConversionException - if the conversion fails

Converter.ConversionException

enumToString

public static String enumToString(Enum<?> value,
                                  Locale locale)

Converts the given enum to a human readable string using the given locale

Compatible with stringToEnum(String, Class, Locale)

Parameters:

value - The enum value to convert

locale - The locale to use for conversion. If null, the JVM default locale will be used

Returns:

A human readable string based on the enum

Throws:

ConversionException - if the conversion fails

convertToPresentation

public String convertToPresentation(Enum value,
                                    Class<? extends String> targetType,
                                    Locale locale)
                             throws Converter.ConversionException

Description copied from interface: Converter

Converts the given value from source type to target type.

A converter can optionally use locale to do the conversion.

A converter should in most cases be symmetric so chaining Converter.convertToPresentation(Object, Class, Locale) and Converter.convertToModel(Object, Class, Locale) should return the original value.

Specified by:

convertToPresentation in interface Converter<String,Enum>

Parameters:

value - The value to convert, compatible with the target type. Can be null

targetType - The requested type of the return value

locale - The locale to use for conversion. Can be null.

Returns:

The converted value compatible with the source type

Throws:

Converter.ConversionException - If the value could not be converted

getModelType

public Class<Enum> getModelType()

Description copied from interface: Converter

The source type of the converter. Values of this type can be passed to Converter.convertToPresentation(Object, Class, Locale).

Specified by:

getModelType in interface Converter<String,Enum>

Returns:

The source type

getPresentationType

public Class<String> getPresentationType()

Description copied from interface: Converter

The target type of the converter. Values of this type can be passed to Converter.convertToModel(Object, Class, Locale).

Specified by:

getPresentationType in interface Converter<String,Enum>

Returns:

The target type