org.springframework.beans
Class DirectFieldAccessor

java.lang.Object
  org.springframework.beans.PropertyEditorRegistrySupport
      org.springframework.beans.AbstractPropertyAccessor
          org.springframework.beans.DirectFieldAccessor

All Implemented Interfaces:

ConfigurablePropertyAccessor, PropertyAccessor, PropertyEditorRegistry, TypeConverter

public class DirectFieldAccessor
extends AbstractPropertyAccessor

PropertyAccessor implementation that directly accesses instance fields. Allows for direct binding to fields instead of going through JavaBean setters.

This implementation just supports fields in the actual target object. It is not able to traverse nested fields.

A DirectFieldAccessor's default for the "extractOldValueForEditor" setting is "true", since a field can always be read without side effects.

Since:

2.0

Author:

Juergen Hoeller

See Also:

AbstractPropertyAccessor.setExtractOldValueForEditor(boolean), BeanWrapper, DirectFieldBindingResult, DataBinder.initDirectFieldAccess()

Field Summary

Fields inherited from interface org.springframework.beans.PropertyAccessor

NESTED_PROPERTY_SEPARATOR, NESTED_PROPERTY_SEPARATOR_CHAR, PROPERTY_KEY_PREFIX, PROPERTY_KEY_PREFIX_CHAR, PROPERTY_KEY_SUFFIX, PROPERTY_KEY_SUFFIX_CHAR

Constructor Summary

DirectFieldAccessor(Object target)
Create a new DirectFieldAccessor for the given target object.

Method Summary

<T> T	convertIfNecessary(Object value, Class<T> requiredType, MethodParameter methodParam) Convert the value to the required type (if necessary from a String).
Class	getPropertyType(String propertyName) Determine the property type for the given property path.
TypeDescriptor	getPropertyTypeDescriptor(String propertyName) Return a type descriptor for the specified property: preferably from the read method, falling back to the write method.
Object	getPropertyValue(String propertyName) Actually get the value of a property.
boolean	isReadableProperty(String propertyName) Determine whether the specified property is readable.
boolean	isWritableProperty(String propertyName) Determine whether the specified property is writable.
void	setPropertyValue(String propertyName, Object newValue) Actually set a property value.

Methods inherited from class org.springframework.beans.AbstractPropertyAccessor

convertIfNecessary, isExtractOldValueForEditor, setExtractOldValueForEditor, setPropertyValue, setPropertyValues, setPropertyValues, setPropertyValues, setPropertyValues

Methods inherited from class org.springframework.beans.PropertyEditorRegistrySupport

copyCustomEditorsTo, copyDefaultEditorsTo, findCustomEditor, getConversionService, getDefaultEditor, guessPropertyTypeFromEditors, hasCustomEditorForElement, isSharedEditor, overrideDefaultEditor, registerCustomEditor, registerCustomEditor, registerDefaultEditors, registerSharedEditor, setConversionService, useConfigValueEditors

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.beans.ConfigurablePropertyAccessor

getConversionService, setConversionService

Methods inherited from interface org.springframework.beans.PropertyEditorRegistry

findCustomEditor, registerCustomEditor, registerCustomEditor

Constructor Detail

DirectFieldAccessor

public DirectFieldAccessor(Object target)

Create a new DirectFieldAccessor for the given target object.

Parameters:

target - the target object to access

Method Detail

isReadableProperty

public boolean isReadableProperty(String propertyName)
                           throws BeansException

Description copied from interface: PropertyAccessor

Determine whether the specified property is readable.

Returns false if the property doesn't exist.

Parameters:

propertyName - the property to check (may be a nested path and/or an indexed/mapped property)

Returns:

whether the property is readable

Throws:

BeansException

isWritableProperty

public boolean isWritableProperty(String propertyName)
                           throws BeansException

Description copied from interface: PropertyAccessor

Determine whether the specified property is writable.

Returns false if the property doesn't exist.

Parameters:

propertyName - the property to check (may be a nested path and/or an indexed/mapped property)

Returns:

whether the property is writable

Throws:

BeansException

getPropertyType

public Class getPropertyType(String propertyName)
                      throws BeansException

Description copied from class: PropertyEditorRegistrySupport

Determine the property type for the given property path.

Called by PropertyEditorRegistrySupport.findCustomEditor(java.lang.Class, java.lang.String) if no required type has been specified, to be able to find a type-specific editor even if just given a property path.

The default implementation always returns null. BeanWrapperImpl overrides this with the standard getPropertyType method as defined by the BeanWrapper interface.

Specified by:

getPropertyType in interface PropertyAccessor

Overrides:

getPropertyType in class AbstractPropertyAccessor

Parameters:

propertyName - the property path to determine the type for

Returns:

the type of the property, or null if not determinable

Throws:

InvalidPropertyException - if there is no such property or if the property isn't readable

PropertyAccessException - if the property was valid but the accessor method failed

BeansException

See Also:

PropertyAccessor.getPropertyType(String)

getPropertyTypeDescriptor

public TypeDescriptor getPropertyTypeDescriptor(String propertyName)
                                         throws BeansException

Description copied from interface: PropertyAccessor

Return a type descriptor for the specified property: preferably from the read method, falling back to the write method.

Parameters:

propertyName - the property to check (may be a nested path and/or an indexed/mapped property)

Returns:

the property type for the particular property, or null if not determinable

Throws:

InvalidPropertyException - if there is no such property or if the property isn't readable

BeansException

getPropertyValue

public Object getPropertyValue(String propertyName)
                        throws BeansException

Description copied from class: AbstractPropertyAccessor

Actually get the value of a property.

Specified by:

getPropertyValue in interface PropertyAccessor

Specified by:

getPropertyValue in class AbstractPropertyAccessor

Parameters:

propertyName - name of the property to get the value of

Returns:

the value of the property

Throws:

InvalidPropertyException - if there is no such property or if the property isn't readable

PropertyAccessException - if the property was valid but the accessor method failed

BeansException

setPropertyValue

public void setPropertyValue(String propertyName,
                             Object newValue)
                      throws BeansException

Description copied from class: AbstractPropertyAccessor

Actually set a property value.

Specified by:

setPropertyValue in interface PropertyAccessor

Specified by:

setPropertyValue in class AbstractPropertyAccessor

Parameters:

propertyName - name of the property to set value of

newValue - the new value

Throws:

InvalidPropertyException - if there is no such property or if the property isn't writable

PropertyAccessException - if the property was valid but the accessor method failed or a type mismatch occured

BeansException

convertIfNecessary

public <T> T convertIfNecessary(Object value,
                                Class<T> requiredType,
                                MethodParameter methodParam)
                     throws TypeMismatchException

Description copied from interface: TypeConverter

Convert the value to the required type (if necessary from a String).

Conversions from String to any type will typically use the setAsText method of the PropertyEditor class. Note that a PropertyEditor must be registered for the given class for this to work; this is a standard JavaBeans API. A number of PropertyEditors are automatically registered.

Parameters:

value - the value to convert

requiredType - the type we must convert to (or null if not known, for example in case of a collection element)

methodParam - the method parameter that is the target of the conversion (for analysis of generic types; may be null)

Returns:

the new value, possibly the result of type conversion

Throws:

TypeMismatchException - if type conversion failed

See Also:

PropertyEditor.setAsText(String), PropertyEditor.getValue()