You need to set enhancementEnabled="true" and have cglib in you classpath.
That will cause ibatis to use EnhancedLazyResultLoader.
There is still some issues with 1:1 enhanced lazy loading.
1) If you use the <discriminator> tag to return 1:1 lazy loaded sub classes
then you will not be able to cast the returned object to the subclass. That's
because the proxy object returned is based on the method return type. I
changed EnhancedLazyResultLoader to not lazy load 1:1 abstract classes. This
reduced the effect of this issue.
2) If the lazy loaded object returns no results you would expect null to be
returned. Instead a proxy object is returned and calling methods on the proxy
object will return null. This was a major problem for me.
E.g. If ( foo.getBar() == null ) {
// Will never happen.
}
To get over this problem I used a custom ResultObjectFactory to add a method
interceptor which would check for the above scenario and return null if
required. I can post that code if needed. If you relationship is 1:1 this
will not be an issue by my relationships were 1 to 0 or 1
3) Its harder to debug cgi enhanced objects using GUI debuggers.
Hope this helps,
Paul
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Sent: Tuesday, 19 December 2006 4:04 PM
To: [email protected]
Subject: Lazy Loading
Hi,
I started using iBATIS recently and I'm trying to use the lazy loading feature
...
according the Developer Guide it is possible to lazy load (1:1) relations, but
after testing an examining the iBATIS code I have the impression lazy loading
only works for collection properties?
in the class LazyResultLoader:
====
public Object loadResult() throws SQLException {
if (Collection.class.isAssignableFrom(targetType)) {
InvocationHandler handler = new LazyResultLoader(client, statementName,
parameterObject, targetType);
ClassLoader cl = targetType.getClassLoader();
return Proxy.newProxyInstance(cl, LIST_INTERFACES, handler);
} else {
return ResultLoader.getResult(client, statementName, parameterObject,
targetType);
}
}
====
mvg,
Wouter Roose
tel.: 02 787 54 08
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