org.apache.struts2.util
Class StrutsTypeConverter

java.lang.Object
  extended by ognl.DefaultTypeConverter
      extended by org.apache.struts2.util.StrutsTypeConverter
All Implemented Interfaces:
ognl.TypeConverter

public abstract class StrutsTypeConverter
extends ognl.DefaultTypeConverter

Base class for type converters used in Struts. This class provides two abstract methods that are used to convert both to and from strings -- the critical functionality that is core to Struts's type coversion system.

Type converters do not have to use this class. It is merely a helper base class, although it is recommended that you use this class as it provides the common type conversion contract required for all web-based type conversion.

There's a hook (fall back method) called performFallbackConversion of which could be used to perform some fallback conversion if convertValue method of this failed. By default it just ask its super class (Ognl's DefaultTypeConverter) to do the conversion.

To allow the framework to recognize that a conversion error has occurred, throw an XWorkException or preferable a TypeConversionException.


Constructor Summary
StrutsTypeConverter()
           
 
Method Summary
abstract  Object convertFromString(Map context, String[] values, Class toClass)
          Converts one or more String values to the specified class.
abstract  String convertToString(Map context, Object o)
          Converts the specified object to a String.
 Object convertValue(Map context, Object o, Class toClass)
           
protected  Object performFallbackConversion(Map context, Object o, Class toClass)
          Hook to perform a fallback conversion if every default options failed.
 
Methods inherited from class ognl.DefaultTypeConverter
convertValue
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

StrutsTypeConverter

public StrutsTypeConverter()
Method Detail

convertValue

public Object convertValue(Map context,
                           Object o,
                           Class toClass)
Overrides:
convertValue in class ognl.DefaultTypeConverter

performFallbackConversion

protected Object performFallbackConversion(Map context,
                                           Object o,
                                           Class toClass)
Hook to perform a fallback conversion if every default options failed. By default this will ask Ognl's DefaultTypeConverter (of which this class extends) to perform the conversion.

Parameters:
context -
o -
toClass -
Returns:
The fallback conversion

convertFromString

public abstract Object convertFromString(Map context,
                                         String[] values,
                                         Class toClass)
Converts one or more String values to the specified class.

Parameters:
context - the action context
values - the String values to be converted, such as those submitted from an HTML form
toClass - the class to convert to
Returns:
the converted object

convertToString

public abstract String convertToString(Map context,
                                       Object o)
Converts the specified object to a String.

Parameters:
context - the action context
o - the object to be converted
Returns:
the converted String


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