/*
* Copyright 2002-2008 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.validation;
import java.beans.PropertyEditor;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.ConfigurablePropertyAccessor;
import org.springframework.beans.MutablePropertyValues;
import org.springframework.beans.PropertyAccessException;
import org.springframework.beans.PropertyAccessorUtils;
import org.springframework.beans.PropertyBatchUpdateException;
import org.springframework.beans.PropertyEditorRegistry;
import org.springframework.beans.PropertyValue;
import org.springframework.beans.PropertyValues;
import org.springframework.beans.SimpleTypeConverter;
import org.springframework.beans.TypeConverter;
import org.springframework.beans.TypeMismatchException;
import org.springframework.core.MethodParameter;
import org.springframework.util.Assert;
import org.springframework.util.ObjectUtils;
import org.springframework.util.PatternMatchUtils;
import org.springframework.util.StringUtils;
/**
* 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.
*
* <p>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 <i>or their nested objects</i>. For this reason, it is
* <b>highly recommended to specify the {@link #setAllowedFields allowedFields} property</b>
* on the DataBinder.
*
* <p>The binding results can be examined via the {@link BindingResult} interface,
* extending the {@link Errors} interface: see the {@link #getBindingResult()} method.
* Missing fields and property access exceptions will be converted to {@link FieldError FieldErrors},
* collected in the Errors instance, using the following error codes:
*
* <ul>
* <li>Missing field error: "required"
* <li>Type mismatch error: "typeMismatch"
* <li>Method invocation error: "methodInvocation"
* </ul>
*
* <p>By default, binding errors get resolved through the {@link BindingErrorProcessor}
* strategy, processing for missing fields and property access exceptions: see the
* {@link #setBindingErrorProcessor} method. You can override the default strategy
* if needed, for example to generate different error codes.
*
* <p>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 {@link org.springframework.context.MessageSource}, which is
* able to resolve an {@link ObjectError}/{@link FieldError} through its
* {@link org.springframework.context.MessageSource#getMessage(org.springframework.context.MessageSourceResolvable, java.util.Locale)}
* method. The list of message codes can be customized through the {@link MessageCodesResolver}
* strategy: see the {@link #setMessageCodesResolver} method. {@link DefaultMessageCodesResolver}'s
* javadoc states details on the default resolution rules.
*
* <p>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 {@link org.springframework.web.bind.ServletRequestDataBinder}
* and {@link org.springframework.web.portlet.bind.PortletRequestDataBinder}.
*
* @author Rod Johnson
* @author Juergen Hoeller
* @author Rob Harrop
* @see #setAllowedFields
* @see #setRequiredFields
* @see #registerCustomEditor
* @see #setMessageCodesResolver
* @see #setBindingErrorProcessor
* @see #bind
* @see #getBindingResult
* @see DefaultMessageCodesResolver
* @see DefaultBindingErrorProcessor
* @see org.springframework.context.MessageSource
* @see org.springframework.web.bind.ServletRequestDataBinder
*/
public class DataBinder implements PropertyEditorRegistry, TypeConverter {
/** Default object name used for binding: "target" */
public static final String DEFAULT_OBJECT_NAME = "target";
/**
* We'll create a lot of DataBinder instances: Let's use a static logger.
*/
protected static final Log logger = LogFactory.getLog(DataBinder.class);
private final Object target;
private final String objectName;
private AbstractPropertyBindingResult bindingResult;
private SimpleTypeConverter typeConverter;
private BindException bindException;
private boolean ignoreUnknownFields = true;
private boolean ignoreInvalidFields = false;
private String[] allowedFields;
private String[] disallowedFields;
private String[] requiredFields;
private BindingErrorProcessor bindingErrorProcessor = new DefaultBindingErrorProcessor();
/**
* Create a new DataBinder instance, with default object name.
* @param target the target object to bind onto (or <code>null</code>
* if the binder is just used to convert a plain parameter value)
* @see #DEFAULT_OBJECT_NAME
*/
public DataBinder(Object target) {
this(target, DEFAULT_OBJECT_NAME);
}
/**
* Create a new DataBinder instance.
* @param target the target object to bind onto (or <code>null</code>
* if the binder is just used to convert a plain parameter value)
* @param objectName the name of the target object
*/
public DataBinder(Object target, String objectName) {
this.target = target;
this.objectName = objectName;
}
/**
* Return the wrapped target object.
*/
public Object getTarget() {
return this.target;
}
/**
* Return the name of the bound object.
*/
public String getObjectName() {
return this.objectName;
}
/**
* Initialize standard JavaBean property access for this DataBinder.
* <p>This is the default; an explicit call just leads to eager initialization.
* @see #initDirectFieldAccess()
*/
public void initBeanPropertyAccess() {
Assert.isNull(this.bindingResult,
"DataBinder is already initialized - call initBeanPropertyAccess before any other configuration methods");
this.bindingResult = new BeanPropertyBindingResult(getTarget(), getObjectName());
}
/**
* Initialize direct field access for this DataBinder,
* as alternative to the default bean property access.
* @see #initBeanPropertyAccess()
*/
public void initDirectFieldAccess() {
Assert.isNull(this.bindingResult,
"DataBinder is already initialized - call initDirectFieldAccess before any other configuration methods");
this.bindingResult = new DirectFieldBindingResult(getTarget(), getObjectName());
}
/**
* Return the internal BindingResult held by this DataBinder,
* as AbstractPropertyBindingResult.
*/
protected AbstractPropertyBindingResult getInternalBindingResult() {
if (this.bindingResult == null) {
initBeanPropertyAccess();
}
return this.bindingResult;
}
/**
* Return the underlying PropertyAccessor of this binder's BindingResult.
*/
protected ConfigurablePropertyAccessor getPropertyAccessor() {
return getInternalBindingResult().getPropertyAccessor();
}
/**
* Return this binder's underlying SimpleTypeConverter.
*/
protected SimpleTypeConverter getSimpleTypeConverter() {
if (this.typeConverter == null) {
this.typeConverter = new SimpleTypeConverter();
}
return this.typeConverter;
}
/**
* Return the underlying TypeConverter of this binder's BindingResult.
*/
protected PropertyEditorRegistry getPropertyEditorRegistry() {
if (getTarget() != null) {
return getInternalBindingResult().getPropertyAccessor();
}
else {
return getSimpleTypeConverter();
}
}
/**
* Return the underlying TypeConverter of this binder's BindingResult.
*/
protected TypeConverter getTypeConverter() {
if (getTarget() != null) {
return getInternalBindingResult().getPropertyAccessor();
}
else {
return getSimpleTypeConverter();
}
}
/**
* Return the BindingResult instance created by this DataBinder.
* This allows for convenient access to the binding results after
* a bind operation.
* @return the BindingResult instance, to be treated as BindingResult
* or as Errors instance (Errors is a super-interface of BindingResult)
* @see Errors
* @see #bind
*/
public BindingResult getBindingResult() {
return getInternalBindingResult();
}
/**
* Return the Errors instance for this data binder.
* @return the Errors instance, to be treated as Errors or as BindException
* @deprecated in favor of {@link #getBindingResult()}.
* Use the {@link BindException#BindException(BindingResult)} constructor
* to create a BindException instance if still needed.
* @see #getBindingResult()
*/
public BindException getErrors() {
if (this.bindException == null) {
this.bindException = new BindException(getBindingResult());
}
return this.bindException;
}
/**
* Set whether to ignore unknown fields, that is, whether to ignore bind
* parameters that do not have corresponding fields in the target object.
* <p>Default is "true". Turn this off to enforce that all bind parameters
* must have a matching field in the target object.
* <p>Note that this setting only applies to <i>binding</i> operations
* on this DataBinder, not to <i>retrieving</i> values via its
* {@link #getBindingResult() BindingResult}.
* @see #bind
*/
public void setIgnoreUnknownFields(boolean ignoreUnknownFields) {
this.ignoreUnknownFields = ignoreUnknownFields;
}
/**
* Return whether to ignore unknown fields when binding.
*/
public boolean isIgnoreUnknownFields() {
return this.ignoreUnknownFields;
}
/**
* 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).
* <p>Default is "false". Turn this on to ignore bind parameters for
* nested objects in non-existing parts of the target object graph.
* <p>Note that this setting only applies to <i>binding</i> operations
* on this DataBinder, not to <i>retrieving</i> values via its
* {@link #getBindingResult() BindingResult}.
* @see #bind
*/
public void setIgnoreInvalidFields(boolean ignoreInvalidFields) {
this.ignoreInvalidFields = ignoreInvalidFields;
}
/**
* Return whether to ignore invalid fields when binding.
*/
public boolean isIgnoreInvalidFields() {
return this.ignoreInvalidFields;
}
/**
* Register fields that should be allowed for binding. Default is all
* fields. Restrict this for example to avoid unwanted modifications
* by malicious users when binding HTTP request parameters.
* <p>Supports "xxx*", "*xxx" and "*xxx*" patterns. More sophisticated matching
* can be implemented by overriding the <code>isAllowed</code> method.
* <p>Alternatively, specify a list of <i>disallowed</i> fields.
* @param allowedFields array of field names
* @see #setDisallowedFields
* @see #isAllowed(String)
* @see org.springframework.web.bind.ServletRequestDataBinder
*/
public void setAllowedFields(String[] allowedFields) {
this.allowedFields = PropertyAccessorUtils.canonicalPropertyNames(allowedFields);
}
/**
* Return the fields that should be allowed for binding.
* @return array of field names
*/
public String[] getAllowedFields() {
return this.allowedFields;
}
/**
* Register fields that should <i>not</i> be allowed for binding. Default is none.
* Mark fields as disallowed for example to avoid unwanted modifications
* by malicious users when binding HTTP request parameters.
* <p>Supports "xxx*", "*xxx" and "*xxx*" patterns. More sophisticated matching
* can be implemented by overriding the <code>isAllowed</code> method.
* <p>Alternatively, specify a list of <i>allowed</i> fields.
* @param disallowedFields array of field names
* @see #setAllowedFields
* @see #isAllowed(String)
* @see org.springframework.web.bind.ServletRequestDataBinder
*/
public void setDisallowedFields(String[] disallowedFields) {
this.disallowedFields = PropertyAccessorUtils.canonicalPropertyNames(disallowedFields);
}
/**
* Return the fields that should <i>not</i> be allowed for binding.
* @return array of field names
*/
public String[] getDisallowedFields() {
return this.disallowedFields;
}
/**
* Register fields that are required for each binding process.
* <p>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).
* @param requiredFields array of field names
* @see #setBindingErrorProcessor
* @see DefaultBindingErrorProcessor#MISSING_FIELD_ERROR_CODE
*/
public void setRequiredFields(String[] requiredFields) {
this.requiredFields = PropertyAccessorUtils.canonicalPropertyNames(requiredFields);
if (logger.isDebugEnabled()) {
logger.debug("DataBinder requires binding of required fields [" +
StringUtils.arrayToCommaDelimitedString(requiredFields) + "]");
}
}
/**
* Return the fields that are required for each binding process.
* @return array of field names
*/
public String[] getRequiredFields() {
return this.requiredFields;
}
/**
* Set whether to extract the old field value when applying a
* property editor to a new value for a field.
* <p>Default is "true", exposing previous field values to custom editors.
* Turn this to "false" to avoid side effects caused by getters.
*/
public void setExtractOldValueForEditor(boolean extractOldValueForEditor) {
getPropertyAccessor().setExtractOldValueForEditor(extractOldValueForEditor);
}
/**
* Set the strategy to use for resolving errors into message codes.
* Applies the given strategy to the underlying errors holder.
* <p>Default is a DefaultMessageCodesResolver.
* @see BeanPropertyBindingResult#setMessageCodesResolver
* @see DefaultMessageCodesResolver
*/
public void setMessageCodesResolver(MessageCodesResolver messageCodesResolver) {
getInternalBindingResult().setMessageCodesResolver(messageCodesResolver);
}
/**
* Set the strategy to use for processing binding errors, that is,
* required field errors and <code>PropertyAccessException</code>s.
* <p>Default is a DefaultBindingErrorProcessor.
* @see DefaultBindingErrorProcessor
*/
public void setBindingErrorProcessor(BindingErrorProcessor bindingErrorProcessor) {
this.bindingErrorProcessor = bindingErrorProcessor;
}
/**
* Return the strategy for processing binding errors.
*/
public BindingErrorProcessor getBindingErrorProcessor() {
return this.bindingErrorProcessor;
}
//---------------------------------------------------------------------
// Implementation of PropertyEditorRegistry/TypeConverter interface
//---------------------------------------------------------------------
public void registerCustomEditor(Class requiredType, PropertyEditor propertyEditor) {
getPropertyEditorRegistry().registerCustomEditor(requiredType, propertyEditor);
}
public void registerCustomEditor(Class requiredType, String field, PropertyEditor propertyEditor) {
getPropertyEditorRegistry().registerCustomEditor(requiredType, field, propertyEditor);
}
public PropertyEditor findCustomEditor(Class requiredType, String propertyPath) {
return getPropertyEditorRegistry().findCustomEditor(requiredType, propertyPath);
}
public Object convertIfNecessary(Object value, Class requiredType) throws TypeMismatchException {
return getTypeConverter().convertIfNecessary(value, requiredType);
}
public Object convertIfNecessary(
Object value, Class requiredType, MethodParameter methodParam) throws TypeMismatchException {
return getTypeConverter().convertIfNecessary(value, requiredType, methodParam);
}
/**
* Bind the given property values to this binder's target.
* <p>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").
* <p>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.
* @param pvs property values to bind
* @see #doBind(org.springframework.beans.MutablePropertyValues)
*/
public void bind(PropertyValues pvs) {
MutablePropertyValues mpvs = (pvs instanceof MutablePropertyValues) ?
(MutablePropertyValues) pvs : new MutablePropertyValues(pvs);
doBind(mpvs);
}
/**
* Actual implementation of the binding process, working with the
* passed-in MutablePropertyValues instance.
* @param mpvs the property values to bind,
* as MutablePropertyValues instance
* @see #checkAllowedFields
* @see #checkRequiredFields
* @see #applyPropertyValues
*/
protected void doBind(MutablePropertyValues mpvs) {
checkAllowedFields(mpvs);
checkRequiredFields(mpvs);
applyPropertyValues(mpvs);
}
/**
* Check the given property values against the allowed fields,
* removing values for fields that are not allowed.
* @param mpvs the property values to be bound (can be modified)
* @see #getAllowedFields
* @see #isAllowed(String)
*/
protected void checkAllowedFields(MutablePropertyValues mpvs) {
PropertyValue[] pvs = mpvs.getPropertyValues();
for (int i = 0; i < pvs.length; i++) {
PropertyValue pv = pvs[i];
String field = PropertyAccessorUtils.canonicalPropertyName(pv.getName());
if (!isAllowed(field)) {
mpvs.removePropertyValue(pv);
getBindingResult().recordSuppressedField(field);
if (logger.isDebugEnabled()) {
logger.debug("Field [" + field + "] has been removed from PropertyValues " +
"and will not be bound, because it has not been found in the list of allowed fields");
}
}
}
}
/**
* Return if the given field is allowed for binding.
* Invoked for each passed-in property value.
* <p>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.
* <p>Can be overridden in subclasses.
* @param field the field to check
* @return if the field is allowed
* @see #setAllowedFields
* @see #setDisallowedFields
* @see org.springframework.util.PatternMatchUtils#simpleMatch(String, String)
*/
protected boolean isAllowed(String field) {
String[] allowed = getAllowedFields();
String[] disallowed = getDisallowedFields();
return ((ObjectUtils.isEmpty(allowed) || PatternMatchUtils.simpleMatch(allowed, field)) &&
(ObjectUtils.isEmpty(disallowed) || !PatternMatchUtils.simpleMatch(disallowed, field)));
}
/**
* Check the given property values against the required fields,
* generating missing field errors where appropriate.
* @param mpvs the property values to be bound (can be modified)
* @see #getRequiredFields
* @see #getBindingErrorProcessor
* @see BindingErrorProcessor#processMissingFieldError
*/
protected void checkRequiredFields(MutablePropertyValues mpvs) {
String[] requiredFields = getRequiredFields();
if (!ObjectUtils.isEmpty(requiredFields)) {
Map propertyValues = new HashMap();
PropertyValue[] pvs = mpvs.getPropertyValues();
for (int i = 0; i < pvs.length; i++) {
PropertyValue pv = pvs[i];
String canonicalName = PropertyAccessorUtils.canonicalPropertyName(pv.getName());
propertyValues.put(canonicalName, pv);
}
for (int i = 0; i < requiredFields.length; i++) {
String field = requiredFields[i];
PropertyValue pv = (PropertyValue) propertyValues.get(field);
if (pv == null || pv.getValue() == null ||
(pv.getValue() instanceof String && !StringUtils.hasText((String) pv.getValue()))) {
// Use bind error processor to create FieldError.
getBindingErrorProcessor().processMissingFieldError(field, getInternalBindingResult());
// Remove property from property values to bind:
// It has already caused a field error with a rejected value.
if (pv != null) {
mpvs.removePropertyValue(pv);
propertyValues.remove(field);
}
}
}
}
}
/**
* Apply given property values to the target object.
* <p>Default implementation applies all of the supplied property
* values as bean property values. By default, unknown fields will
* be ignored.
* @param mpvs the property values to be bound (can be modified)
* @see #getTarget
* @see #getPropertyAccessor
* @see #isIgnoreUnknownFields
* @see #getBindingErrorProcessor
* @see BindingErrorProcessor#processPropertyAccessException
*/
protected void applyPropertyValues(MutablePropertyValues mpvs) {
try {
// Bind request parameters onto target object.
getPropertyAccessor().setPropertyValues(mpvs, isIgnoreUnknownFields(), isIgnoreInvalidFields());
}
catch (PropertyBatchUpdateException ex) {
// Use bind error processor to create FieldErrors.
PropertyAccessException[] exs = ex.getPropertyAccessExceptions();
for (int i = 0; i < exs.length; i++) {
getBindingErrorProcessor().processPropertyAccessException(exs[i], getInternalBindingResult());
}
}
}
/**
* Close this DataBinder, which may result in throwing
* a BindException if it encountered any errors.
* @return the model Map, containing target object and Errors instance
* @throws BindException if there were any errors in the bind operation
* @see BindingResult#getModel()
*/
public Map close() throws BindException {
if (getBindingResult().hasErrors()) {
throw new BindException(getBindingResult());
}
return getBindingResult().getModel();
}
}