public class BeanToPropertyValueTransformer extends Object implements org.apache.commons.collections.Transformer
Transformer that outputs a property value.
An implementation of org.apache.commons.collections.Transformer that transforms
the object provided by returning the value of a specified property of the object. The
constructor for BeanToPropertyValueTransformer requires the name of the property
that will be used in the transformation. The property can be a simple, nested, indexed, or
mapped property as defined by org.apache.commons.beanutils.PropertyUtils. If any
object in the property path specified by propertyName is null then the
outcome is based on the value of the ignoreNull attribute.
A typical usage might look like:
// create the transformer
BeanToPropertyValueTransformer transformer = new BeanToPropertyValueTransformer( "person.address.city" );
// transform the Collection
Collection peoplesCities = CollectionUtils.collect( peopleCollection, transformer );
This would take a Collection of person objects and return a Collection
of objects which represents the cities in which each person lived. Assuming...
peeopleCollection is an object which represents a
person.
getAddress() method which returns an object which
represents a person's address.
getCity() method which returns an object which
represents the city in which a person lives.
PropertyUtils,
Transformer| Constructor and Description |
|---|
BeanToPropertyValueTransformer(String propertyName)
Constructs a Transformer which does not ignore nulls.
|
BeanToPropertyValueTransformer(String propertyName,
boolean ignoreNull)
Constructs a Transformer and sets ignoreNull.
|
| Modifier and Type | Method and Description |
|---|---|
String |
getPropertyName()
Returns the name of the property that will be used in the transformation of the bean.
|
boolean |
isIgnoreNull()
Returns the flag which determines whether
null objects in the property path will
genenerate an IllegalArgumentException or not. |
Object |
transform(Object object)
Returns the value of the property named in the transformer's constructor for
the object provided.
|
public BeanToPropertyValueTransformer(String propertyName)
ignoreNull to be false.propertyName - The name of the property that will be used in the transformation.IllegalArgumentException - If the propertyName is null or
empty.public BeanToPropertyValueTransformer(String propertyName, boolean ignoreNull)
null objects in the property path will
genenerate an IllegalArgumentException or not.propertyName - The name of the property that will be used in the transformation.ignoreNull - Determines whether null objects in the property path will
genenerate an IllegalArgumentException or not.IllegalArgumentException - If the propertyName is null or
empty.public Object transform(Object object)
null then the outcome will be based on the value of the ignoreNull
attribute. By default, ignoreNull is false and would result in an
IllegalArgumentException if an object in the property path leading up to the
target property is null.transform in interface org.apache.commons.collections.Transformerobject - The object to be transformed.IllegalArgumentException - If an IllegalAccessException, InvocationTargetException, or
NoSuchMethodException is thrown when trying to access the property specified on the object
provided. Or if an object in the property path provided is null and
ignoreNull is set to false.public String getPropertyName()
public boolean isIgnoreNull()
null objects in the property path will
genenerate an IllegalArgumentException or not. If set to true then
if any objects in the property path evaluate to null then the
IllegalArgumentException throw by PropertyUtils will be logged but
not rethrown and null will be returned. If set to false then if any
objects in the property path evaluate to null then the
IllegalArgumentException throw by PropertyUtils will be logged and
rethrown.null objects in the property path will
genenerate an IllegalArgumentException or not.Copyright © 2000–2019 The Apache Software Foundation. All rights reserved.