org.apache.commons.beanutils
Class ConvertUtilsBean

java.lang.Object
  org.apache.commons.beanutils.ConvertUtilsBean

Direct Known Subclasses:

ConvertUtilsBean2

public class ConvertUtilsBean
extends Object

Utility methods for converting String scalar values to objects of the specified Class, String arrays to arrays of the specified Class. The actual Converter instance to be used can be registered for each possible destination Class. Unless you override them, standard Converter instances are provided for all of the following destination Classes:

• java.lang.BigDecimal (no default value)
• java.lang.BigInteger (no default value)
• boolean and java.lang.Boolean (default to false)
• byte and java.lang.Byte (default to zero)
• char and java.lang.Character (default to a space)
• java.lang.Class (no default value)
• double and java.lang.Double (default to zero)
• float and java.lang.Float (default to zero)
• int and java.lang.Integer (default to zero)
• long and java.lang.Long (default to zero)
• short and java.lang.Short (default to zero)
• java.lang.String (default to null)
• java.io.File (no default value)
• java.net.URL (no default value)
• java.sql.Date (no default value)
• java.sql.Time (no default value)
• java.sql.Timestamp (no default value)

For backwards compatibility, the standard Converters for primitive types (and the corresponding wrapper classes) return a defined default value when a conversion error occurs. If you prefer to have a ConversionException thrown instead, replace the standard Converter instances with instances created with the zero-arguments constructor. For example, to cause the Converters for integers to throw an exception on conversion errors, you could do this:

   // No-args constructor gets the version that throws exceptions
   Converter myConverter =
    new org.apache.commons.beanutils.converter.IntegerConverter();
   ConvertUtils.register(myConverter, Integer.TYPE);    // Native type
   ConvertUtils.register(myConverter, Integer.class);   // Wrapper class
 

Converters generally treat null input as if it were invalid input, ie they return their default value if one was specified when the converter was constructed, and throw an exception otherwise. If you prefer nulls to be preserved for converters that are converting to objects (not primitives) then register a converter as above, passing a default value of null to the converter constructor (and of course registering that converter only for the .class target).

When a converter is listed above as having no default value, then that converter will throw an exception when passed null or an invalid value as its input. In particular, by default the BigInteger and BigDecimal converters have no default (and are therefore somewhat inconsistent with the other numerical converters which all have zero as their default).

Converters that generate arrays of each of the primitive types are also automatically configured (including String[]). When passed null or invalid input, these return an empty array (not null). See class AbstractArrayConverter for the supported input formats for these converters.

Since:

1.7

Version:

$Revision: 745079 $ $Date: 2009-02-17 14:04:10 +0000 (Tue, 17 Feb 2009) $

Author:

Craig R. McClanahan, Ralph Schaer, Chris Audley, James Strachan

Constructor Summary

ConvertUtilsBean()
Construct a bean with standard converters registered

Method Summary

String	convert(Object value) Convert the specified value into a String.
Object	convert(Object value, Class targetType) Convert the value to an object of the specified class (if possible).
Object	convert(String[] values, Class clazz) Convert an array of specified values to an array of objects of the specified class (if possible).
Object	convert(String value, Class clazz) Convert the specified value to an object of the specified class (if possible).
void	deregister() Remove all registered Converters, and re-establish the standard Converters.
void	deregister(Class clazz) Remove any registered Converter for the specified destination Class.
boolean	getDefaultBoolean() Deprecated. Register replacement converters for Boolean.TYPE and Boolean.class instead
byte	getDefaultByte() Deprecated. Register replacement converters for Byte.TYPE and Byte.class instead
char	getDefaultCharacter() Deprecated. Register replacement converters for Character.TYPE and Character.class instead
double	getDefaultDouble() Deprecated. Register replacement converters for Double.TYPE and Double.class instead
float	getDefaultFloat() Deprecated. Register replacement converters for Float.TYPE and Float.class instead
int	getDefaultInteger() Deprecated. Register replacement converters for Integer.TYPE and Integer.class instead
long	getDefaultLong() Deprecated. Register replacement converters for Long.TYPE and Long.class instead
short	getDefaultShort() Deprecated. Register replacement converters for Short.TYPE and Short.class instead
protected static ConvertUtilsBean	getInstance() Get singleton instance
Converter	lookup(Class clazz) Look up and return any registered Converter for the specified destination class; if there is no registered Converter, return null.
Converter	lookup(Class sourceType, Class targetType) Look up and return any registered Converter for the specified source and destination class; if there is no registered Converter, return null.
void	register(boolean throwException, boolean defaultNull, int defaultArraySize) Register the provided converters with the specified defaults.
void	register(Converter converter, Class clazz) Register a custom Converter for the specified destination Class, replacing any previously registered Converter.
void	setDefaultBoolean(boolean newDefaultBoolean) Deprecated. Register replacement converters for Boolean.TYPE and Boolean.class instead
void	setDefaultByte(byte newDefaultByte) Deprecated. Register replacement converters for Byte.TYPE and Byte.class instead
void	setDefaultCharacter(char newDefaultCharacter) Deprecated. Register replacement converters for Character.TYPE and Character.class instead
void	setDefaultDouble(double newDefaultDouble) Deprecated. Register replacement converters for Double.TYPE and Double.class instead
void	setDefaultFloat(float newDefaultFloat) Deprecated. Register replacement converters for Float.TYPE and Float.class instead
void	setDefaultInteger(int newDefaultInteger) Deprecated. Register replacement converters for Integer.TYPE and Integer.class instead
void	setDefaultLong(long newDefaultLong) Deprecated. Register replacement converters for Long.TYPE and Long.class instead
void	setDefaultShort(short newDefaultShort) Deprecated. Register replacement converters for Short.TYPE and Short.class instead

Methods inherited from class java.lang.Object

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

Constructor Detail

ConvertUtilsBean

public ConvertUtilsBean()

Construct a bean with standard converters registered

Method Detail

getInstance

protected static ConvertUtilsBean getInstance()

Get singleton instance

Returns:

The singleton instance

getDefaultBoolean

public boolean getDefaultBoolean()

Deprecated. Register replacement converters for Boolean.TYPE and Boolean.class instead

Gets the default value for Boolean conversions.

Returns:

The default Boolean value

setDefaultBoolean

public void setDefaultBoolean(boolean newDefaultBoolean)

Deprecated. Register replacement converters for Boolean.TYPE and Boolean.class instead

Sets the default value for Boolean conversions.

Parameters:

newDefaultBoolean - The default Boolean value

getDefaultByte

public byte getDefaultByte()

Deprecated. Register replacement converters for Byte.TYPE and Byte.class instead

Gets the default value for Byte conversions.

Returns:

The default Byte value

setDefaultByte

public void setDefaultByte(byte newDefaultByte)

Deprecated. Register replacement converters for Byte.TYPE and Byte.class instead

Sets the default value for Byte conversions.

Parameters:

newDefaultByte - The default Byte value

getDefaultCharacter

public char getDefaultCharacter()

Deprecated. Register replacement converters for Character.TYPE and Character.class instead

Gets the default value for Character conversions.

Returns:

The default Character value

setDefaultCharacter

public void setDefaultCharacter(char newDefaultCharacter)

Deprecated. Register replacement converters for Character.TYPE and Character.class instead

Sets the default value for Character conversions.

Parameters:

newDefaultCharacter - The default Character value

getDefaultDouble

public double getDefaultDouble()

Deprecated. Register replacement converters for Double.TYPE and Double.class instead

Gets the default value for Double conversions.

Returns:

The default Double value

setDefaultDouble

public void setDefaultDouble(double newDefaultDouble)

Deprecated. Register replacement converters for Double.TYPE and Double.class instead

Sets the default value for Double conversions.

Parameters:

newDefaultDouble - The default Double value

getDefaultFloat

public float getDefaultFloat()

Deprecated. Register replacement converters for Float.TYPE and Float.class instead

Gets the default value for Float conversions.

Returns:

The default Float value

setDefaultFloat

public void setDefaultFloat(float newDefaultFloat)

Deprecated. Register replacement converters for Float.TYPE and Float.class instead

Sets the default value for Float conversions.

Parameters:

newDefaultFloat - The default Float value

getDefaultInteger

public int getDefaultInteger()

Deprecated. Register replacement converters for Integer.TYPE and Integer.class instead

Gets the default value for Integer conversions.

Returns:

The default Integer value

setDefaultInteger

public void setDefaultInteger(int newDefaultInteger)

Deprecated. Register replacement converters for Integer.TYPE and Integer.class instead

Sets the default value for Integer conversions.

Parameters:

newDefaultInteger - The default Integer value

getDefaultLong

public long getDefaultLong()

Deprecated. Register replacement converters for Long.TYPE and Long.class instead

Gets the default value for Long conversions.

Returns:

The default Long value

setDefaultLong

public void setDefaultLong(long newDefaultLong)

Deprecated. Register replacement converters for Long.TYPE and Long.class instead

Sets the default value for Long conversions.

Parameters:

newDefaultLong - The default Long value

getDefaultShort

public short getDefaultShort()

Deprecated. Register replacement converters for Short.TYPE and Short.class instead

Gets the default value for Short conversions.

Returns:

The default Short value

setDefaultShort

public void setDefaultShort(short newDefaultShort)

Deprecated. Register replacement converters for Short.TYPE and Short.class instead

Sets the default value for Short conversions.

Parameters:

newDefaultShort - The default Short value

convert

public String convert(Object value)

Convert the specified value into a String. If the specified value is an array, the first element (converted to a String) will be returned. The registered Converter for the java.lang.String class will be used, which allows applications to customize Object->String conversions (the default implementation simply uses toString()).

Parameters:

value - Value to be converted (may be null)

Returns:

The converted String value

convert

public Object convert(String value,
                      Class clazz)

Convert the specified value to an object of the specified class (if possible). Otherwise, return a String representation of the value.

Parameters:

value - Value to be converted (may be null)

clazz - Java class to be converted to

Returns:

The converted value

Throws:

ConversionException - if thrown by an underlying Converter

convert

public Object convert(String[] values,
                      Class clazz)

Convert an array of specified values to an array of objects of the specified class (if possible). If the specified Java class is itself an array class, this class will be the type of the returned value. Otherwise, an array will be constructed whose component type is the specified class.

Parameters:

values - Array of values to be converted

clazz - Java array or element class to be converted to

Returns:

The converted value

Throws:

ConversionException - if thrown by an underlying Converter

convert

public Object convert(Object value,
                      Class targetType)

Convert the value to an object of the specified class (if possible).

Parameters:

value - Value to be converted (may be null)

targetType - Class of the value to be converted to

Returns:

The converted value

Throws:

ConversionException - if thrown by an underlying Converter

deregister

public void deregister()

Remove all registered Converters, and re-establish the standard Converters.

register

public void register(boolean throwException,
                     boolean defaultNull,
                     int defaultArraySize)

Register the provided converters with the specified defaults.

Parameters:

throwException - true if the converters should throw an exception when a conversion error occurs, otherwise false if a default value should be used.

defaultNull - trueif the standard converters (see registerStandard(boolean, boolean)) should use a default value of null, otherwise false. N.B. This values is ignored if throwException is true

defaultArraySize - The size of the default array value for array converters (N.B. This values is ignored if throwException is true). Specifying a value less than zero causes a null value to be used for the default.

deregister

public void deregister(Class clazz)

Remove any registered Converter for the specified destination Class.

Parameters:

clazz - Class for which to remove a registered Converter

lookup

public Converter lookup(Class clazz)

Look up and return any registered Converter for the specified destination class; if there is no registered Converter, return null.

Parameters:

clazz - Class for which to return a registered Converter

Returns:

The registered Converter or null if not found

lookup

public Converter lookup(Class sourceType,
                        Class targetType)

Look up and return any registered Converter for the specified source and destination class; if there is no registered Converter, return null.

Parameters:

sourceType - Class of the value being converted

targetType - Class of the value to be converted to

Returns:

The registered Converter or null if not found

register

public void register(Converter converter,
                     Class clazz)

Register a custom Converter for the specified destination Class, replacing any previously registered Converter.

Parameters:

converter - Converter to be registered

clazz - Destination class for conversions performed by this Converter