org.springframework.beans.DirectFieldAccessor Maven / Gradle / Ivy
/*
* Copyright 2002-2006 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.PropertyChangeEvent;
import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.Map;
import org.springframework.util.Assert;
import org.springframework.util.ReflectionUtils;
/**
* 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.
*
* @author Juergen Hoeller
* @since 2.0
* @see #setExtractOldValueForEditor
* @see BeanWrapper
* @see org.springframework.validation.DirectFieldBindingResult
* @see org.springframework.validation.DataBinder#initDirectFieldAccess()
*/
public class DirectFieldAccessor extends AbstractPropertyAccessor {
private final Object target;
private final Map fieldMap = new HashMap();
private final TypeConverterDelegate typeConverterDelegate;
/**
* Create a new DirectFieldAccessor for the given target object.
* @param target the target object to access
*/
public DirectFieldAccessor(Object target) {
Assert.notNull(target, "Target object must not be null");
this.target = target;
ReflectionUtils.doWithFields(this.target.getClass(), new ReflectionUtils.FieldCallback() {
public void doWith(Field field) {
fieldMap.put(field.getName(), field);
}
});
this.typeConverterDelegate = new TypeConverterDelegate(this, target);
setExtractOldValueForEditor(true);
}
public boolean isReadableProperty(String propertyName) throws BeansException {
return this.fieldMap.containsKey(propertyName);
}
public boolean isWritableProperty(String propertyName) throws BeansException {
return this.fieldMap.containsKey(propertyName);
}
public Class getPropertyType(String propertyName) throws BeansException {
Field field = (Field) this.fieldMap.get(propertyName);
if (field != null) {
return field.getType();
}
return null;
}
public Object getPropertyValue(String propertyName) throws BeansException {
Field field = (Field) this.fieldMap.get(propertyName);
if (field == null) {
throw new NotReadablePropertyException(
this.target.getClass(), propertyName, "Field '" + propertyName + "' does not exist");
}
try {
ReflectionUtils.makeAccessible(field);
return field.get(this.target);
}
catch (IllegalAccessException ex) {
throw new InvalidPropertyException(this.target.getClass(), propertyName, "Field is not accessible", ex);
}
}
public void setPropertyValue(String propertyName, Object newValue) throws BeansException {
Field field = (Field) this.fieldMap.get(propertyName);
if (field == null) {
throw new NotWritablePropertyException(
this.target.getClass(), propertyName, "Field '" + propertyName + "' does not exist");
}
Object oldValue = null;
try {
ReflectionUtils.makeAccessible(field);
oldValue = field.get(this.target);
Object convertedValue =
this.typeConverterDelegate.convertIfNecessary(propertyName, oldValue, newValue, field.getType());
field.set(this.target, convertedValue);
}
catch (IllegalAccessException ex) {
throw new InvalidPropertyException(this.target.getClass(), propertyName, "Field is not accessible", ex);
}
catch (IllegalArgumentException ex) {
PropertyChangeEvent pce = new PropertyChangeEvent(this.target, propertyName, oldValue, newValue);
throw new TypeMismatchException(pce, field.getType(), ex);
}
}
}