Module org.jhotdraw8.base

Package org.jhotdraw8.base.converter

Class DefaultConverter

java.lang.Object

org.jhotdraw8.base.converter.DefaultConverter

All Implemented Interfaces:

Converter<Object>

public class DefaultConverter
extends Object
implements Converter<Object>

Converts an Object to a String but can not a String back to an Object.

This converter is not bijective, and thus only useful for one-way conversions to a String. For example for generating a message text.

• The conversion to string is performed by invoking the toString method on the value object.
• The fromString method always returns a String object regardless of the type that was converted toString.
• If a null value is converted to string, the string contains the text "null". On the conversion from string, a String object with the value "null" is returned.

Author:

Werner Randelshofer

Constructor Summary

Constructors

Constructor	Description
DefaultConverter()

Method Summary

Modifier and Type	Method	Description
@Nullable Object	fromString(@NonNull CharBuffer buf, @Nullable IdResolver idResolver)	Constructs a value from a string.
@Nullable String	getDefaultValue()	Provides a default value for APIs which always require a value even if conversion from String failed.
void	toString(@NonNull Appendable out, @Nullable IdSupplier idSupplier, @Nullable Object value)	Converts a value to a string and appends it to the provided Appendable.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jhotdraw8.base.converter.Converter

fromString, fromString, fromString, getHelpText, needsIdResolver, toString, toString, toString

Constructor Details

DefaultConverter

public DefaultConverter()

Method Details

fromString

public @Nullable Object fromString(@NonNull CharBuffer buf,
 @Nullable IdResolver idResolver)

Description copied from interface: Converter

Constructs a value from a string.

The converter should try to create the value greedily, by consuming as many characters as possible for the value.

This method does not change the state of the converter.

Specified by:

fromString in interface Converter<Object>

Parameters:

buf - A char buffer which holds the string. The char buffer must be treated as read only! The position of the char buffer denotes the beginning of the string when this method is invoked. After completion of this method, the position is set after the last consumed character.

idResolver - The factory for looking up object ids. Nullable for non-resolving converters.

Returns:

The value. Nullable.

toString

public void toString(@NonNull Appendable out,
 @Nullable IdSupplier idSupplier,
 @Nullable Object value)
              throws IOException

Description copied from interface: Converter

Converts a value to a string and appends it to the provided Appendable.

This method does not change the state of the converter.

Specified by:

toString in interface Converter<Object>

Parameters:

out - The appendable

idSupplier - The factory for creating object ids. Nullable for non-resolving converters.

value - The value. Nullable.

Throws:

IOException - thrown by Appendable

getDefaultValue

public @Nullable String getDefaultValue()

Description copied from interface: Converter

Provides a default value for APIs which always require a value even if conversion from String failed.

Specified by:

getDefaultValue in interface Converter<Object>

Returns:

The default value to use when conversion from String failed.