Package org.apache.commons.beanutils.converters

Class NumberConverter

java.lang.Object

org.apache.commons.beanutils.converters.AbstractConverter

org.apache.commons.beanutils.converters.NumberConverter

All Implemented Interfaces:

Converter

Direct Known Subclasses:

BigDecimalConverter, BigIntegerConverter, ByteConverter, DoubleConverter, FloatConverter, IntegerConverter, LongConverter, ShortConverter

public abstract class NumberConverter
extends AbstractConverter

Converter implementation that handles conversion to and from java.lang.Number objects.

This implementation handles conversion for the following java.lang.Number types.

• java.lang.Byte
• java.lang.Short
• java.lang.Integer
• java.lang.Long
• java.lang.Float
• java.lang.Double
• java.math.BigDecimal
• java.math.BigInteger

String Conversions (to and from)

This class provides a number of ways in which number conversions to/from Strings can be achieved:

• Using the default format for the default Locale, configure using:
  • setUseLocaleFormat(true)
• Using the default format for a specified Locale, configure using:
  • setLocale(Locale)
• Using a specified pattern for the default Locale, configure using:
  • setPattern(String)
• Using a specified pattern for a specified Locale, configure using:
  • setPattern(String)
  • setLocale(Locale)
• If none of the above are configured the toNumber(String) method is used to convert from String to Number and the Number's toString() method used to convert from Number to String.

N.B.Patterns can only be specified using the standard pattern characters and NOT in localized form (see java.text.DecimalFormat). For example to cater for number styles used in Germany such as 0.000,00 the pattern is specified in the normal form 0,000.00 and the locale set to Locale.GERMANY.

Since:

1.8.0

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	allowDecimals
private java.util.Locale	locale
private static java.lang.Integer	ONE
private java.lang.String	pattern
private boolean	useLocaleFormat
private static java.lang.Integer	ZERO

Constructor Summary

Constructors

Constructor	Description
NumberConverter(boolean allowDecimals)	Construct a java.lang.Number Converter that throws a ConversionException if a error occurs.
NumberConverter(boolean allowDecimals, java.lang.Object defaultValue)	Construct a java.lang.Number Converter that returns a default value if an error occurs.

Method Summary

Modifier and Type	Method	Description
protected java.lang.String	convertToString(java.lang.Object value)	Convert an input Number object into a String.
protected <T> T	convertToType(java.lang.Class<T> targetType, java.lang.Object value)	Convert the input object into a Number object of the specified type.
private java.text.NumberFormat	getFormat()	Return a NumberFormat to use for Conversion.
java.util.Locale	getLocale()	Return the Locale for the Converter (or null if none specified).
java.lang.String	getPattern()	Return the number format pattern used to convert Numbers to/from a java.lang.String (or null if none specified).
boolean	isAllowDecimals()	Tests whether decimals are allowed in the number.
private java.lang.Number	parse(java.lang.Class<?> sourceType, java.lang.Class<?> targetType, java.lang.String value, java.text.NumberFormat format)	Convert a String into a Number object.
void	setLocale(java.util.Locale locale)	Set the Locale for the Converter.
void	setPattern(java.lang.String pattern)	Set a number format pattern to use to convert Numbers to/from a java.lang.String.
void	setUseLocaleFormat(boolean useLocaleFormat)	Set whether a format should be used to convert the Number.
private java.lang.Number	toNumber(java.lang.Class<?> sourceType, java.lang.Class<?> targetType, java.lang.String value)	Default String to Number conversion.
private <T> T	toNumber(java.lang.Class<?> sourceType, java.lang.Class<T> targetType, java.lang.Number value)	Convert any Number object to the specified type for this Converter.
java.lang.String	toString()	Provide a String representation of this number converter.

Methods inherited from class org.apache.commons.beanutils.converters.AbstractConverter

conversionException, convert, convertArray, getDefault, getDefaultType, handleError, handleMissing, isUseDefault, log, setDefaultValue, toString

Methods inherited from class java.lang.Object

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

Field Detail

ZERO

private static final java.lang.Integer ZERO

ONE

private static final java.lang.Integer ONE

pattern

private java.lang.String pattern

allowDecimals

private final boolean allowDecimals

useLocaleFormat

private boolean useLocaleFormat

locale

private java.util.Locale locale

Constructor Detail

NumberConverter

public NumberConverter(boolean allowDecimals)

Construct a java.lang.Number Converter that throws a ConversionException if a error occurs.

Parameters:

allowDecimals - Indicates whether decimals are allowed

NumberConverter

public NumberConverter(boolean allowDecimals,
                       java.lang.Object defaultValue)

Construct a java.lang.Number Converter that returns a default value if an error occurs.

Parameters:

allowDecimals - Indicates whether decimals are allowed

defaultValue - The default value to be returned

Method Detail

convertToString

protected java.lang.String convertToString(java.lang.Object value)
                                    throws java.lang.Throwable

Convert an input Number object into a String.

Overrides:

convertToString in class AbstractConverter

Parameters:

value - The input value to be converted

Returns:

the converted String value.

Throws:

java.lang.Throwable - if an error occurs converting to a String

convertToType

protected <T> T convertToType(java.lang.Class<T> targetType,
                              java.lang.Object value)
                       throws java.lang.Throwable

Convert the input object into a Number object of the specified type.

Specified by:

convertToType in class AbstractConverter

Type Parameters:

T - Target type of the conversion.

Parameters:

targetType - Data type to which this value should be converted.

value - The input value to be converted.

Returns:

The converted value.

Throws:

java.lang.Throwable - if an error occurs converting to the specified type

getFormat

private java.text.NumberFormat getFormat()

Return a NumberFormat to use for Conversion.

Returns:

The NumberFormat.

getLocale

public java.util.Locale getLocale()

Return the Locale for the Converter (or null if none specified).

Returns:

The locale to use for conversion

getPattern

public java.lang.String getPattern()

Return the number format pattern used to convert Numbers to/from a java.lang.String (or null if none specified).

See java.text.DecimalFormat for details of how to specify the pattern.

Returns:

The format pattern.

isAllowDecimals

public boolean isAllowDecimals()

Tests whether decimals are allowed in the number.

Returns:

Whether decimals are allowed in the number

parse

private java.lang.Number parse(java.lang.Class<?> sourceType,
                               java.lang.Class<?> targetType,
                               java.lang.String value,
                               java.text.NumberFormat format)

Convert a String into a Number object.

Parameters:

sourceType - the source type of the conversion

targetType - The type to convert the value to

value - The String date value.

format - The NumberFormat to parse the String value.

Returns:

The converted Number object.

Throws:

ConversionException - if the String cannot be converted.

setLocale

public void setLocale(java.util.Locale locale)

Set the Locale for the Converter.

Parameters:

locale - The locale to use for conversion

setPattern

public void setPattern(java.lang.String pattern)

Set a number format pattern to use to convert Numbers to/from a java.lang.String.

See java.text.DecimalFormat for details of how to specify the pattern.

Parameters:

pattern - The format pattern.

setUseLocaleFormat

public void setUseLocaleFormat(boolean useLocaleFormat)

Set whether a format should be used to convert the Number.

Parameters:

useLocaleFormat - true if a number format should be used.

toNumber

private java.lang.Number toNumber(java.lang.Class<?> sourceType,
                                  java.lang.Class<?> targetType,
                                  java.lang.String value)

Default String to Number conversion.

This method handles conversion from a String to the following types:

• java.lang.Byte
• java.lang.Short
• java.lang.Integer
• java.lang.Long
• java.lang.Float
• java.lang.Double
• java.math.BigDecimal
• java.math.BigInteger

Parameters:

sourceType - The type being converted from

targetType - The Number type to convert to

value - The String value to convert.

Returns:

The converted Number value.

toNumber

private <T> T toNumber(java.lang.Class<?> sourceType,
                       java.lang.Class<T> targetType,
                       java.lang.Number value)

Convert any Number object to the specified type for this Converter.

This method handles conversion to the following types:

• java.lang.Byte
• java.lang.Short
• java.lang.Integer
• java.lang.Long
• java.lang.Float
• java.lang.Double
• java.math.BigDecimal
• java.math.BigInteger

Parameters:

sourceType - The type being converted from

targetType - The Number type to convert to

value - The Number to convert.

Returns:

The converted value.

toString

public java.lang.String toString()

Provide a String representation of this number converter.

Overrides:

toString in class AbstractConverter

Returns:

A String representation of this number converter