| [aspectj-dev] Context-dependent casting with aspects? |
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Hi, I'm new to AOP, and I would like to start using it to introduce a caching aspect on many classes of my project. I am afraid this is not possible, because of the context-dependent casting I have to do.
Maybe a code snippet (below) shows best what I would like to do.
1) Class OriginalVersion is the kind of code I have now, without caching. The example shows a field of type "TypeX" (which could be any type) with a getter and a setter methods
.
2) CachedVersion is the kind of code I would like to obtain at the end. The field is now a CachedValue, which I access from the getter and setter methods.
The problem is, that I have to cast to (TypeX) in the getter method. For every kind of variable type, I have to use a different cast: if valueX is of type String, I have to cast to String, if it is of type Date, I have to cast to date.
As far as I understand, I cannot o this with aspectj. I cannot write an aspect that automatically casts to the right type.
Please tell me I'm wrong ;-)
Many thanks in advance for your help!
Vito
public class OriginalVersion {
private TypeX valueX;
public TypeX getValueX() {
return valueX;
}
public void setValueX(TypeX valueX) {
this.valueX = valueX;
}
}
public class CachedVersion {
CachedValue cachedX = new CachedValueImpl();
public TypeX getValueX() {
// the type-dependent cast is the problem
return (TypeX)cachedX.getValue();
}
public void setValueX(TypeX valueX) {
cachedX.putValue(valueX);
}
}
interface CachedValue {
public Object getValue();
public void putValue(Object valueX);
}
Dr. Vito Baggiolini
CERN AB/CO
1211 Geneva 23 __________________________________________________ Ihre eMails auf dem Handy lesen - ohne Zeitverlust - 24h/Tag |