XWorkConverter (XWork: Core 2.3.16.1 API)

java.lang.Object
- com.opensymphony.xwork2.conversion.impl.DefaultTypeConverter
- - com.opensymphony.xwork2.conversion.impl.XWorkConverter

All Implemented Interfaces:

TypeConverter

Direct Known Subclasses:

AnnotationXWorkConverter
```
public class XWorkConverter
extends DefaultTypeConverter
```
XWorkConverter is a singleton used by many of the Struts 2's Ognl extention points, such as InstantiatingNullHandler, XWorkListPropertyAccessor etc to do object conversion.

Type conversion is great for situations where you need to turn a String in to a more complex object. Because the web is type-agnostic (everything is a string in HTTP), Struts 2's type conversion features are very useful. For instance, if you were prompting a user to enter in coordinates in the form of a string (such as "3, 22"), you could have Struts 2 do the conversion both from String to Point and from Point to String.

Using this "point" example, if your action (or another compound object in which you are setting properties on) has a corresponding ClassName-conversion.properties file, Struts 2 will use the configured type converters for conversion to and from strings. So turning "3, 22" in to new Point(3, 22) is done by merely adding the following entry to ClassName-conversion.properties (Note that the PointConverter should impl the TypeConverter interface):

point = com.acme.PointConverter

Your type converter should be sure to check what class type it is being requested to convert. Because it is used for both to and from strings, you will need to split the conversion method in to two parts: one that turns Strings in to Points, and one that turns Points in to Strings.

After this is done, you can now reference your point (using <s:property value="point"/> in JSP or ${point} in FreeMarker) and it will be printed as "3, 22" again. As such, if you submit this back to an action, it will be converted back to a Point once again.

In some situations you may wish to apply a type converter globally. This can be done by editing the file xwork-conversion.properties in the root of your class path (typically WEB-INF/classes) and providing a property in the form of the class name of the object you wish to convert on the left hand side and the class name of the type converter on the right hand side. For example, providing a type converter for all Point objects would mean adding the following entry:

com.acme.Point = com.acme.PointConverter

Type conversion should not be used as a substitute for i18n. It is not recommended to use this feature to print out properly formatted dates. Rather, you should use the i18n features of Struts 2 (and consult the JavaDocs for JDK's MessageFormat object) to see how a properly formatted date should be displayed.

Any error that occurs during type conversion may or may not wish to be reported. For example, reporting that the input "abc" could not be converted to a number might be important. On the other hand, reporting that an empty string, "", cannot be converted to a number might not be important - especially in a web environment where it is hard to distinguish between a user not entering a value vs. entering a blank value.

By default, all conversion errors are reported using the generic i18n key xwork.default.invalid.fieldvalue, which you can override (the default text is Invalid field value for field "xxx", where xxx is the field name) in your global i18n resource bundle.

However, sometimes you may wish to override this message on a per-field basis. You can do this by adding an i18n key associated with just your action (Action.properties) using the pattern invalid.fieldvalue.xxx, where xxx is the field name.

It is important to know that none of these errors are actually reported directly. Rather, they are added to a map called conversionErrors in the ActionContext. There are several ways this map can then be accessed and the errors can be reported accordingly.

Version:

$Date$ $Id$

Author:

Pat Lightbody, Rainer Hermanns, Alexandru Popescu, tm_jee

See Also:
XWorkBasicConverter

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`CONVERSION_COLLECTION_PREFIX`
`static String`	`CONVERSION_ERROR_PROPERTY_PREFIX`
`static String`	`CONVERSION_PROPERTY_FULLNAME`
`static String`	`LAST_BEAN_CLASS_ACCESSED`
`static String`	`LAST_BEAN_PROPERTY_ACCESSED`
`static String`	`MESSAGE_INDEX_BRACKET_PATTERN`
`static String`	`MESSAGE_INDEX_PATTERN`
`static Pattern`	`messageIndexPattern`
`static String`	`PERIOD`
`static String`	`REPORT_CONVERSION_ERRORS`

Fields inherited from class com.opensymphony.xwork2.conversion.impl.DefaultTypeConverter
MILLISECOND_FORMAT

Fields inherited from interface com.opensymphony.xwork2.conversion.TypeConverter
NO_CONVERSION_POSSIBLE, TYPE_CONVERTER_CONTEXT_KEY

Constructor Summary

Constructors
Modifier Constructor and Description

protected XWorkConverter()

Constructors
Modifier	Constructor and Description
`protected`	`XWorkConverter()`

Method Summary

Methods
Modifier and Type	Method and Description
`protected void`	`addConverterMapping(Map<String,Object> mapping, Class clazz)` Looks for converter mappings for the specified class and adds it to an existing map.
`String`	`buildConverterFilename(Class clazz)`
`protected Map<String,Object>`	`buildConverterMapping(Class clazz)` Looks for converter mappings for the specified class, traversing up its class hierarchy and interfaces and adding any additional mappings it may find.
`Object`	`convertValue(Map<String,Object> map, Object o, Class aClass)`
`Object`	`convertValue(Map<String,Object> context, Object target, Member member, String property, Object value, Class toClass)` Convert value from one form to another.
`static String`	`getConversionErrorMessage(String propertyName, ValueStack stack)`
`protected Object`	`getConverter(Class clazz, String property)`
`protected void`	`handleConversionException(Map<String,Object> context, String property, Object value, Object object)`
`TypeConverter`	`lookup(Class clazz)` Looks for a TypeConverter in the default mappings.
`TypeConverter`	`lookup(String className)` Looks for a TypeConverter in the default mappings.
`void`	`registerConverter(String className, TypeConverter converter)`
`void`	`registerConverterNotFound(String className)`
`void`	`setConversionAnnotationProcessor(ConversionAnnotationProcessor annotationProcessor)`
`void`	`setConversionFileProcessor(ConversionFileProcessor fileProcessor)`
`void`	`setConversionPropertiesProcessor(ConversionPropertiesProcessor propertiesProcessor)`
`void`	`setDefaultTypeConverter(XWorkBasicConverter conv)`
`void`	`setFileManagerFactory(FileManagerFactory fileManagerFactory)`
`void`	`setReloadingConfigs(String reloadingConfigs)`
`void`	`setTypeConverterHolder(TypeConverterHolder converterHolder)`

Methods inherited from class com.opensymphony.xwork2.conversion.impl.DefaultTypeConverter
bigDecValue, bigIntValue, booleanValue, convertValue, doubleValue, enumValue, getLocale, getTypeConverter, longValue, stringValue, stringValue

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - REPORT_CONVERSION_ERRORS
```
public static final String REPORT_CONVERSION_ERRORS
```
    See Also:
    Constant Field Values
  - CONVERSION_PROPERTY_FULLNAME
```
public static final String CONVERSION_PROPERTY_FULLNAME
```
    See Also:
    Constant Field Values
  - CONVERSION_ERROR_PROPERTY_PREFIX
```
public static final String CONVERSION_ERROR_PROPERTY_PREFIX
```
    See Also:
    Constant Field Values
  - CONVERSION_COLLECTION_PREFIX
```
public static final String CONVERSION_COLLECTION_PREFIX
```
    See Also:
    Constant Field Values
  - LAST_BEAN_CLASS_ACCESSED
```
public static final String LAST_BEAN_CLASS_ACCESSED
```
    See Also:
    Constant Field Values
  - LAST_BEAN_PROPERTY_ACCESSED
```
public static final String LAST_BEAN_PROPERTY_ACCESSED
```
    See Also:
    Constant Field Values
  - MESSAGE_INDEX_PATTERN
```
public static final String MESSAGE_INDEX_PATTERN
```
    See Also:
    Constant Field Values
  - MESSAGE_INDEX_BRACKET_PATTERN
```
public static final String MESSAGE_INDEX_BRACKET_PATTERN
```
    See Also:
    Constant Field Values
  - PERIOD
```
public static final String PERIOD
```
    See Also:
    Constant Field Values
  - messageIndexPattern
```
public static final Pattern messageIndexPattern
```
- Constructor Detail
  - XWorkConverter
```
protected XWorkConverter()
```
- Method Detail
  - setDefaultTypeConverter
```
public void setDefaultTypeConverter(XWorkBasicConverter conv)
```
  - setFileManagerFactory
```
public void setFileManagerFactory(FileManagerFactory fileManagerFactory)
```
  - setReloadingConfigs
```
public void setReloadingConfigs(String reloadingConfigs)
```
  - setConversionPropertiesProcessor
```
public void setConversionPropertiesProcessor(ConversionPropertiesProcessor propertiesProcessor)
```
  - setConversionFileProcessor
```
public void setConversionFileProcessor(ConversionFileProcessor fileProcessor)
```
  - setConversionAnnotationProcessor
```
public void setConversionAnnotationProcessor(ConversionAnnotationProcessor annotationProcessor)
```
  - setTypeConverterHolder
```
public void setTypeConverterHolder(TypeConverterHolder converterHolder)
```
  - getConversionErrorMessage
```
public static String getConversionErrorMessage(String propertyName,
                               ValueStack stack)
```
  - buildConverterFilename
```
public String buildConverterFilename(Class clazz)
```
  - convertValue
```
public Object convertValue(Map<String,Object> map,
                  Object o,
                  Class aClass)
```
    Overrides:
    
    convertValue in class DefaultTypeConverter
  - convertValue
```
public Object convertValue(Map<String,Object> context,
                  Object target,
                  Member member,
                  String property,
                  Object value,
                  Class toClass)
```
    Convert value from one form to another. Minimum requirement of arguments:
    - supplying context, toClass and value
    - supplying context, target and value.
    Specified by:
    
    convertValue in interface TypeConverter
    
    Overrides:
    
    convertValue in class DefaultTypeConverter
    
    Parameters:
    context - context under which the conversion is being done
    target - target object in which the property is being set
    member - member (Constructor, Method or Field) being set
    property - property name being set
    value - value to be converted
    toClass - type to which value is converted
    
    Returns:
    Converted value of type toType or TypeConverter.NoConversionPossible to indicate that the conversion was not possible.
    See Also:
    TypeConverter.convertValue(java.util.Map, java.lang.Object, java.lang.reflect.Member, java.lang.String, java.lang.Object, java.lang.Class)
  - lookup
```
public TypeConverter lookup(String className)
```
    Looks for a TypeConverter in the default mappings.
    
    Parameters:
    className - name of the class the TypeConverter must handle
    
    Returns:
    a TypeConverter to handle the specified class or null if none can be found
  - lookup
```
public TypeConverter lookup(Class clazz)
```
    Looks for a TypeConverter in the default mappings.
    
    Parameters:
    clazz - the class the TypeConverter must handle
    
    Returns:
    a TypeConverter to handle the specified class or null if none can be found
  - getConverter
```
protected Object getConverter(Class clazz,
                  String property)
```
  - handleConversionException
```
protected void handleConversionException(Map<String,Object> context,
                             String property,
                             Object value,
                             Object object)
```
  - registerConverter
```
public void registerConverter(String className,
                     TypeConverter converter)
```
  - registerConverterNotFound
```
public void registerConverterNotFound(String className)
```
  - addConverterMapping
```
protected void addConverterMapping(Map<String,Object> mapping,
                       Class clazz)
```
    Looks for converter mappings for the specified class and adds it to an existing map. Only new converters are added. If a converter is defined on a key that already exists, the converter is ignored.
    
    Parameters:
    mapping - an existing map to add new converter mappings to
    clazz - class to look for converter mappings for
  - buildConverterMapping
```
protected Map<String,Object> buildConverterMapping(Class clazz)
                                            throws Exception
```
    Looks for converter mappings for the specified class, traversing up its class hierarchy and interfaces and adding any additional mappings it may find. Mappings lower in the hierarchy have priority over those higher in the hierarcy.
    
    Parameters:
    clazz - the class to look for converter mappings for
    
    Returns:
    the converter mappings
    
    Throws:
    
    Exception

Class XWorkConverter

Field Summary

Fields inherited from class com.opensymphony.xwork2.conversion.impl.DefaultTypeConverter

Fields inherited from interface com.opensymphony.xwork2.conversion.TypeConverter

Constructor Summary

Method Summary

Methods inherited from class com.opensymphony.xwork2.conversion.impl.DefaultTypeConverter

Methods inherited from class java.lang.Object

Field Detail

REPORT_CONVERSION_ERRORS

CONVERSION_PROPERTY_FULLNAME

CONVERSION_ERROR_PROPERTY_PREFIX

CONVERSION_COLLECTION_PREFIX

LAST_BEAN_CLASS_ACCESSED

LAST_BEAN_PROPERTY_ACCESSED

MESSAGE_INDEX_PATTERN

MESSAGE_INDEX_BRACKET_PATTERN

PERIOD

messageIndexPattern

Constructor Detail

XWorkConverter

Method Detail

setDefaultTypeConverter

setFileManagerFactory

setReloadingConfigs

setConversionPropertiesProcessor

setConversionFileProcessor

setConversionAnnotationProcessor

setTypeConverterHolder

getConversionErrorMessage

buildConverterFilename

convertValue

convertValue

lookup

lookup

getConverter

handleConversionException

registerConverter

registerConverterNotFound

addConverterMapping

buildConverterMapping