/*
* Copyright 2002-2009 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.beans;
import java.beans.PropertyDescriptor;
/**
* The central interface of Spring's low-level JavaBeans infrastructure.
*
* <p>Typically not used directly but rather implicitly via a
* {@link org.springframework.beans.factory.BeanFactory} or a
* {@link org.springframework.validation.DataBinder}.
*
* <p>Provides operations to analyze and manipulate standard JavaBeans:
* the ability to get and set property values (individually or in bulk),
* get property descriptors, and query the readability/writability of properties.
*
* <p>This interface supports <b>nested properties</b> enabling the setting
* of properties on subproperties to an unlimited depth.
*
* <p>A BeanWrapper's default for the "extractOldValueForEditor" setting
* is "false", to avoid side effects caused by getter method invocations.
* Turn this to "true" to expose present property values to custom editors.
*
* @author Rod Johnson
* @author Juergen Hoeller
* @since 13 April 2001
* @see PropertyAccessor
* @see PropertyEditorRegistry
* @see PropertyAccessorFactory#forBeanPropertyAccess
* @see org.springframework.beans.factory.BeanFactory
* @see org.springframework.validation.BeanPropertyBindingResult
* @see org.springframework.validation.DataBinder#initBeanPropertyAccess()
*/
public interface BeanWrapper extends ConfigurablePropertyAccessor {
/**
* Return the bean instance wrapped by this object, if any.
* @return the bean instance, or <code>null</code> if none set
*/
Object getWrappedInstance();
/**
* Return the type of the wrapped JavaBean object.
* @return the type of the wrapped bean instance,
* or <code>null</code> if no wrapped object has been set
*/
Class getWrappedClass();
/**
* Obtain the PropertyDescriptors for the wrapped object
* (as determined by standard JavaBeans introspection).
* @return the PropertyDescriptors for the wrapped object
*/
PropertyDescriptor[] getPropertyDescriptors();
/**
* Obtain the property descriptor for a specific property
* of the wrapped object.
* @param propertyName the property to obtain the descriptor for
* (may be a nested path, but no indexed/mapped property)
* @return the property descriptor for the specified property
* @throws InvalidPropertyException if there is no such property
*/
PropertyDescriptor getPropertyDescriptor(String propertyName) throws InvalidPropertyException;
/**
* Set whether this BeanWrapper should attempt to "auto-grow" a nested path that contains a null value.
* <p>If "true", a null path location will be populated with a default object value and traversed
* instead of resulting in a {@link NullValueInNestedPathException}. Turning this flag on also
* enables auto-growth of collection elements when accessing an out-of-bounds index.
* <p>Default is "false" on a plain BeanWrapper.
*/
void setAutoGrowNestedPaths(boolean autoGrowNestedPaths);
/**
* Return whether "auto-growing" of nested paths has been activated.
*/
boolean isAutoGrowNestedPaths();
}
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