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java.lang.Object org.springframework.validation.DataBinder
public class DataBinder
Binder that allows for setting property values onto a target object, including support for validation and binding result analysis. The binding process can be customized through specifying allowed fields, required fields, custom editors, etc.
Note that there are potential security implications in failing to set an array
of allowed fields. In the case of HTTP form POST data for example, malicious clients
can attempt to subvert an application by supplying values for fields or properties
that do not exist on the form. In some cases this could lead to illegal data being
set on command objects or their nested objects. For this reason, it is
highly recommended to specify the allowedFields
property
on the DataBinder.
The binding results can be examined via the BindingResult
interface,
extending the Errors
interface: see the getBindingResult()
method.
Missing fields and property access exceptions will be converted to FieldErrors
,
collected in the Errors instance, using the following error codes:
By default, binding errors get resolved through the BindingErrorProcessor
strategy, processing for missing fields and property access exceptions: see the
setBindingErrorProcessor(org.springframework.validation.BindingErrorProcessor)
method. You can override the default strategy
if needed, for example to generate different error codes.
Custom validation errors can be added afterwards. You will typically want to resolve
such error codes into proper user-visible error messages; this can be achieved through
resolving each error via a MessageSource
, which is
able to resolve an ObjectError
/FieldError
through its
MessageSource.getMessage(org.springframework.context.MessageSourceResolvable, java.util.Locale)
method. The list of message codes can be customized through the MessageCodesResolver
strategy: see the setMessageCodesResolver(org.springframework.validation.MessageCodesResolver)
method. DefaultMessageCodesResolver
's
javadoc states details on the default resolution rules.
This generic data binder can be used in any kind of environment.
It is typically used by Spring web MVC controllers, via the web-specific
subclasses ServletRequestDataBinder
and PortletRequestDataBinder
.
setAllowedFields(java.lang.String[])
,
setRequiredFields(java.lang.String[])
,
registerCustomEditor(java.lang.Class, java.beans.PropertyEditor)
,
setMessageCodesResolver(org.springframework.validation.MessageCodesResolver)
,
setBindingErrorProcessor(org.springframework.validation.BindingErrorProcessor)
,
bind(org.springframework.beans.PropertyValues)
,
getBindingResult()
,
DefaultMessageCodesResolver
,
DefaultBindingErrorProcessor
,
MessageSource
,
ServletRequestDataBinder
Field Summary | |
---|---|
static String |
DEFAULT_OBJECT_NAME
Default object name used for binding: "target" |
protected static Log |
logger
We'll create a lot of DataBinder instances: Let's use a static logger. |
Constructor Summary | |
---|---|
DataBinder(Object target)
Create a new DataBinder instance, with default object name. |
|
DataBinder(Object target,
String objectName)
Create a new DataBinder instance. |
Method Summary | |
---|---|
protected void |
applyPropertyValues(MutablePropertyValues mpvs)
Apply given property values to the target object. |
void |
bind(PropertyValues pvs)
Bind the given property values to this binder's target. |
protected void |
checkAllowedFields(MutablePropertyValues mpvs)
Check the given property values against the allowed fields, removing values for fields that are not allowed. |
protected void |
checkRequiredFields(MutablePropertyValues mpvs)
Check the given property values against the required fields, generating missing field errors where appropriate. |
Map |
close()
Close this DataBinder, which may result in throwing a BindException if it encountered any errors. |
protected void |
doBind(MutablePropertyValues mpvs)
Actual implementation of the binding process, working with the passed-in MutablePropertyValues instance. |
PropertyEditor |
findCustomEditor(Class requiredType,
String propertyPath)
Find a custom property editor for the given type and property. |
String[] |
getAllowedFields()
Return the fields that should be allowed for binding. |
BindingErrorProcessor |
getBindingErrorProcessor()
Return the strategy for processing binding errors. |
BindingResult |
getBindingResult()
Return the BindingResult instance created by this DataBinder. |
String[] |
getDisallowedFields()
Return the fields that should not be allowed for binding. |
BindException |
getErrors()
Deprecated. in favor of getBindingResult() .
Use the BindException.BindException(BindingResult) constructor
to create a BindException instance if still needed. |
protected AbstractPropertyBindingResult |
getInternalBindingResult()
Return the internal BindingResult held by this DataBinder, as AbstractPropertyBindingResult. |
String |
getObjectName()
Return the name of the bound object. |
protected ConfigurablePropertyAccessor |
getPropertyAccessor()
Return the underlying PropertyAccessor of this binder's BindingResult. |
String[] |
getRequiredFields()
Return the fields that are required for each binding process. |
Object |
getTarget()
Return the wrapped target object. |
void |
initBeanPropertyAccess()
Initialize standard JavaBean property access for this DataBinder. |
void |
initDirectFieldAccess()
Initialize direct field access for this DataBinder, as alternative to the default bean property access. |
protected boolean |
isAllowed(String field)
Return if the given field is allowed for binding. |
boolean |
isIgnoreInvalidFields()
Return whether to ignore invalid fields when binding. |
boolean |
isIgnoreUnknownFields()
Return whether to ignore unknown fields when binding. |
void |
registerCustomEditor(Class requiredType,
PropertyEditor propertyEditor)
Register the given custom property editor for all properties of the given type. |
void |
registerCustomEditor(Class requiredType,
String field,
PropertyEditor propertyEditor)
Register the given custom property editor for the given type and property, or for all properties of the given type. |
void |
setAllowedFields(String[] allowedFields)
Register fields that should be allowed for binding. |
void |
setBindingErrorProcessor(BindingErrorProcessor bindingErrorProcessor)
Set the strategy to use for processing binding errors, that is, required field errors and PropertyAccessException s. |
void |
setDisallowedFields(String[] disallowedFields)
Register fields that should not be allowed for binding. |
void |
setExtractOldValueForEditor(boolean extractOldValueForEditor)
Set whether to extract the old field value when applying a property editor to a new value for a field. |
void |
setIgnoreInvalidFields(boolean ignoreInvalidFields)
Set whether to ignore invalid fields, that is, whether to ignore bind parameters that have corresponding fields in the target object which are not accessible (for example because of null values in the nested path). |
void |
setIgnoreUnknownFields(boolean ignoreUnknownFields)
Set whether to ignore unknown fields, that is, whether to ignore bind parameters that do not have corresponding fields in the target object. |
void |
setMessageCodesResolver(MessageCodesResolver messageCodesResolver)
Set the strategy to use for resolving errors into message codes. |
void |
setRequiredFields(String[] requiredFields)
Register fields that are required for each binding process. |
Methods inherited from class java.lang.Object |
---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
---|
public static final String DEFAULT_OBJECT_NAME
protected static final Log logger
Constructor Detail |
---|
public DataBinder(Object target)
target
- target object to bind ontoDEFAULT_OBJECT_NAME
public DataBinder(Object target, String objectName)
target
- target object to bind ontoobjectName
- name of the target objectMethod Detail |
---|
public Object getTarget()
public String getObjectName()
public void initBeanPropertyAccess()
This is the default; an explicit call just leads to eager initialization.
initDirectFieldAccess()
public void initDirectFieldAccess()
initBeanPropertyAccess()
protected AbstractPropertyBindingResult getInternalBindingResult()
protected ConfigurablePropertyAccessor getPropertyAccessor()
public BindingResult getBindingResult()
Errors
,
bind(org.springframework.beans.PropertyValues)
public BindException getErrors()
getBindingResult()
.
Use the BindException.BindException(BindingResult)
constructor
to create a BindException instance if still needed.
getBindingResult()
public void setIgnoreUnknownFields(boolean ignoreUnknownFields)
Default is "true". Turn this off to enforce that all bind parameters must have a matching field in the target object.
Note that this setting only applies to binding operations
on this DataBinder, not to retrieving values via its
BindingResult
.
public boolean isIgnoreUnknownFields()
public void setIgnoreInvalidFields(boolean ignoreInvalidFields)
Default is "false". Turn this on to ignore bind parameters for nested objects in non-existing parts of the target object graph.
Note that this setting only applies to binding operations
on this DataBinder, not to retrieving values via its
BindingResult
.
public boolean isIgnoreInvalidFields()
public void setAllowedFields(String[] allowedFields)
Supports "xxx*", "*xxx" and "*xxx*" patterns. More sophisticated matching
can be implemented by overriding the isAllowed
method.
Alternatively, specify a list of disallowed fields.
allowedFields
- array of field namessetDisallowedFields(java.lang.String[])
,
isAllowed(String)
,
ServletRequestDataBinder
public String[] getAllowedFields()
public void setDisallowedFields(String[] disallowedFields)
Supports "xxx*", "*xxx" and "*xxx*" patterns. More sophisticated matching
can be implemented by overriding the isAllowed
method.
Alternatively, specify a list of allowed fields.
disallowedFields
- array of field namessetAllowedFields(java.lang.String[])
,
isAllowed(String)
,
ServletRequestDataBinder
public String[] getDisallowedFields()
public void setRequiredFields(String[] requiredFields)
If one of the specified fields is not contained in the list of incoming property values, a corresponding "missing field" error will be created, with error code "required" (by the default binding error processor).
requiredFields
- array of field namessetBindingErrorProcessor(org.springframework.validation.BindingErrorProcessor)
,
DefaultBindingErrorProcessor.MISSING_FIELD_ERROR_CODE
public String[] getRequiredFields()
public void setExtractOldValueForEditor(boolean extractOldValueForEditor)
Default is "true", exposing previous field values to custom editors. Turn this to "false" to avoid side effects caused by getters.
public void registerCustomEditor(Class requiredType, PropertyEditor propertyEditor)
PropertyEditorRegistry
registerCustomEditor
in interface PropertyEditorRegistry
requiredType
- the type of the propertypropertyEditor
- the editor to registerpublic void registerCustomEditor(Class requiredType, String field, PropertyEditor propertyEditor)
PropertyEditorRegistry
If the property path denotes an array or Collection property,
the editor will get applied either to the array/Collection itself
(the PropertyEditor
has to create an array or Collection value) or
to each element (the PropertyEditor
has to create the element type),
depending on the specified required type.
Note: Only one single registered custom editor per property path is supported. In the case of a Collection/array, do not register an editor for both the Collection/array and each element on the same property.
For example, if you wanted to register an editor for "items[n].quantity" (for all values n), you would use "items.quality" as the value of the 'propertyPath' argument to this method.
registerCustomEditor
in interface PropertyEditorRegistry
requiredType
- the type of the property (can be null
if a property
is given but should be specified in any case for consistency checking)field
- the path of the property (name or nested path), or
null
if registering an editor for all properties of the given typepropertyEditor
- editor to registerpublic PropertyEditor findCustomEditor(Class requiredType, String propertyPath)
PropertyEditorRegistry
findCustomEditor
in interface PropertyEditorRegistry
requiredType
- the type of the property (can be null
if a property
is given but should be specified in any case for consistency checking)propertyPath
- the path of the property (name or nested path), or
null
if looking for an editor for all properties of the given type
null
if nonepublic void setMessageCodesResolver(MessageCodesResolver messageCodesResolver)
Default is a DefaultMessageCodesResolver.
public void setBindingErrorProcessor(BindingErrorProcessor bindingErrorProcessor)
PropertyAccessException
s.
Default is a DefaultBindingErrorProcessor.
DefaultBindingErrorProcessor
public BindingErrorProcessor getBindingErrorProcessor()
public void bind(PropertyValues pvs)
This call can create field errors, representing basic binding errors like a required field (code "required"), or type mismatch between value and bean property (code "typeMismatch").
Note that the given PropertyValues should be a throwaway instance: For efficiency, it will be modified to just contain allowed fields if it implements the MutablePropertyValues interface; else, an internal mutable copy will be created for this purpose. Pass in a copy of the PropertyValues if you want your original instance to stay unmodified in any case.
pvs
- property values to binddoBind(org.springframework.beans.MutablePropertyValues)
protected void doBind(MutablePropertyValues mpvs)
mpvs
- the property values to bind,
as MutablePropertyValues instancecheckAllowedFields(org.springframework.beans.MutablePropertyValues)
,
checkRequiredFields(org.springframework.beans.MutablePropertyValues)
,
applyPropertyValues(org.springframework.beans.MutablePropertyValues)
protected void checkAllowedFields(MutablePropertyValues mpvs)
mpvs
- the property values to be bound (can be modified)getAllowedFields()
,
isAllowed(String)
protected boolean isAllowed(String field)
The default implementation checks for "xxx*", "*xxx" and "*xxx*" matches, as well as direct equality, in the specified lists of allowed fields and disallowed fields. A field matching a disallowed pattern will not be accepted even if it also happens to match a pattern in the allowed list.
Can be overridden in subclasses.
field
- the field to check
setAllowedFields(java.lang.String[])
,
setDisallowedFields(java.lang.String[])
,
PatternMatchUtils.simpleMatch(String, String)
protected void checkRequiredFields(MutablePropertyValues mpvs)
mpvs
- the property values to be bound (can be modified)getRequiredFields()
,
getBindingErrorProcessor()
,
BindingErrorProcessor.processMissingFieldError(java.lang.String, org.springframework.validation.BindingResult)
protected void applyPropertyValues(MutablePropertyValues mpvs)
Default implementation applies all of the supplied property values as bean property values. By default, unknown fields will be ignored.
mpvs
- the property values to be bound (can be modified)getTarget()
,
getPropertyAccessor()
,
isIgnoreUnknownFields()
,
getBindingErrorProcessor()
,
BindingErrorProcessor.processPropertyAccessException(org.springframework.beans.PropertyAccessException, org.springframework.validation.BindingResult)
public Map close() throws BindException
BindException
- if there were any errors in the bind operationBindingResult.getModel()
|
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