[
https://issues.apache.org/jira/browse/BEANUTILS-526?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Marco Janc updated BEANUTILS-526:
---------------------------------
Description:
The function _BeanUtils.copyProperty(bean, name, value)_ shall instantiate
nested properties before copying them.
*Example:*
{code:java}
class Foo
{
Bar bar;
}
class Bar
{
int id;
}
{code}
We now have an instance of _Foo_ where _bar_ property is null and call:
{code:java}
Foo foo = new Foo();
BeanUtils.copyProperty(foo, "bar.id", 3);
{code}
This will throw an exception currently.
*Workaround*
In my generic copy method, i instantiate all required nested properties before.
Here my implementation. In BeanUtils this could be done more lazy when the
target is null.
{code:java}
/**
* Instantiates the nested properties of the given Object with proxy
Objects
* with the given property fieldname.
*
* @param obj
* @param fieldName
*
* @throws NoSuchMethodException
* @throws InvocationTargetException
* @throws IllegalAccessException
* @throws InstantiationException
*/
public static void instantiateNestedProperties(final Object obj, final
String fieldName)
throws IllegalAccessException, InvocationTargetException,
NoSuchMethodException, InstantiationException
{
final String[] fieldNames = fieldName.split("\\.");
if (fieldNames.length == 1)
return; final StringBuffer nestedProperty = new
StringBuffer(); // outsource temporary variables to optimize performance
String fn = null;
Object value = null;
PropertyDescriptor propertyDescriptor = null;
Class<?> propertyType = null;
Object newInstance = null; for (int i = 0; i <
fieldNames.length - 1; i++)
{
fn = fieldNames[i];
if (i != 0)
nestedProperty.append(".");
nestedProperty.append(fn); value =
PropertyUtils.getProperty(obj, nestedProperty.toString());
if (value == null)
{
propertyDescriptor =
PropertyUtils.getPropertyDescriptor(obj, nestedProperty.toString());
propertyType =
propertyDescriptor.getPropertyType();
newInstance = propertyType.newInstance();
PropertyUtils.setProperty(obj,
nestedProperty.toString(), newInstance);
}
}
}
{code}
was:
The function _BeanUtils.copyProperty(bean, name, value)_ shall instantiate
nested properties before copying them.
*Example:*
{code:java}
{code}
*class Foo*
*{*
*Bar bar;*
*}*
*class Bar*
*{*
*int id;*
*}*
We now have an instance of _Foo_ where _bar_ property is null and call:
{code:java}
Foo foo = new Foo();
BeanUtils.copyProperty(foo, "bar.id", 3);
{code}
This will throw an exception currently.
*Workaround*
In my generic copy method, i instantiate all required nested properties before.
> copyProperty should instantiate nested properties
> -------------------------------------------------
>
> Key: BEANUTILS-526
> URL: https://issues.apache.org/jira/browse/BEANUTILS-526
> Project: Commons BeanUtils
> Issue Type: Bug
> Components: Bean / Property Utils
> Affects Versions: 1.9.4
> Reporter: Marco Janc
> Priority: Major
>
> The function _BeanUtils.copyProperty(bean, name, value)_ shall instantiate
> nested properties before copying them.
>
> *Example:*
>
> {code:java}
> class Foo
> {
> Bar bar;
> }
> class Bar
> {
> int id;
> }
> {code}
>
>
> We now have an instance of _Foo_ where _bar_ property is null and call:
>
> {code:java}
> Foo foo = new Foo();
> BeanUtils.copyProperty(foo, "bar.id", 3);
> {code}
> This will throw an exception currently.
>
> *Workaround*
> In my generic copy method, i instantiate all required nested properties
> before. Here my implementation. In BeanUtils this could be done more lazy
> when the target is null.
>
> {code:java}
> /**
> * Instantiates the nested properties of the given Object with proxy
> Objects
> * with the given property fieldname.
> *
> * @param obj
> * @param fieldName
> *
> * @throws NoSuchMethodException
> * @throws InvocationTargetException
> * @throws IllegalAccessException
> * @throws InstantiationException
> */
> public static void instantiateNestedProperties(final Object obj, final
> String fieldName)
> throws IllegalAccessException, InvocationTargetException,
> NoSuchMethodException, InstantiationException
> {
> final String[] fieldNames = fieldName.split("\\.");
> if (fieldNames.length == 1)
> return; final StringBuffer nestedProperty = new
> StringBuffer(); // outsource temporary variables to optimize
> performance
> String fn = null;
> Object value = null;
> PropertyDescriptor propertyDescriptor = null;
> Class<?> propertyType = null;
> Object newInstance = null; for (int i = 0; i <
> fieldNames.length - 1; i++)
> {
> fn = fieldNames[i];
> if (i != 0)
> nestedProperty.append(".");
> nestedProperty.append(fn); value =
> PropertyUtils.getProperty(obj, nestedProperty.toString());
> if (value == null)
> {
> propertyDescriptor =
> PropertyUtils.getPropertyDescriptor(obj, nestedProperty.toString());
> propertyType =
> propertyDescriptor.getPropertyType();
> newInstance = propertyType.newInstance();
> PropertyUtils.setProperty(obj,
> nestedProperty.toString(), newInstance);
> }
> }
> }
> {code}
>
>
>
>
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