I've two classes (A and B) that extend a base class BASE. I need to make a report that takes an array of such classes and the prints the fields of A or B. I tought of using conditional expressions, then casting to one or another (depending on a field value). But I can't cast, because I don't know how to refere to the current bean.
To do this I am using a JRBeanCollectionDataSource filled with a List<BASE>. How do I cast every bean to A or B in a report (or subreport)? I tried:
((A)this)
but it says basically that this contains the report instance, not the current bean and gives error.
use ((A) BASE) suppose BASE is your BASE class
now BASE point to the current record
Related
I am not sure which relationship between classes would be adequate for a class which returns a created object or gets an object as parameter(see uploaded picture). I guess that aggregation/composition is wrong since Class1 does not own the object/does not have it as an attribute. Also I think that an association is wrong since Class1 does not refers to a pointer.
Thank you in advance for any answers.
That would simply be dependencies:
An association is created in case you have a stronger relation between classes. That is either one is holding a more permanent relation (in form of an attribute) rather than a temporary one like in using them as passing parameter or return parameter. From an UML point of view an association is basically a stronger form of a dependency.
Note that the untyped attributes you sketched are of no interest in this context and I just left them out.
According to a comment of #www.admiraalit.nl: If Class1 creates new instances of Class3, the dependency may have the ≪create≫ stereotype, see table 22.1 of the UML spec. v2.5.1. In that case the dependency would be a usage (chap. 7.8.23) which is just a bit stronger
a class which returns a created object or gets an object as parameter(see uploaded picture)
you mean for a class having an operation returning ... and an other getting ...
I guess that aggregation/composition is wrong since Class1 does not own the object/does not have it as an attribute
you are right
Also I think that an association is wrong since Class1 does not refers to a pointer.
whatever by pointer or by value (which is target language dependent) an association is not right because there is no attribute in Class1 whose type is Class2 or Class3
The only possible relation between Class1 and Class2 or Class3 seems to be a dependency, but to have them does not have a real plus value, the profile of the operations already give that information
I want to change the format of my data, from RDD(Label:String,(ID:String,Data:Array[Double])) to an RDD Object with the label, id and data as components.
But when I print my RDD consecutively twice, the references of objects change :
class Data_Object(private val id:String, private var vector:Vector) extends Serializable {
var label = ""
...
}
First print
(1,ms3.Data_Object#35062c11)
(2,ms3.Data_Object#25789aa9)
Second print
(2,ms3.Data_Object#6bf5d886)
(1,ms3.Data_Object#a4eb65)
I think that explains why the subtract method doesn't work. So can I use subtract with objects as values, or do I return to my classic model ?
Unless you specify otherwise, objects in Scala (and Java) are compared using reference equality (i.e. their memory address). They are also printed out according to this address, hence the Data_Object#6bf5d886 and so on.
Using reference equality means that two Data_Object instances with identical properties will NOT compare as equal unless they are exactly the same object. Also, their references will change from one run to the next.
Particularly in a distributed system like Spark, this is no good - we need to be able to tell whether two objects in two different JVMs are the same or not, according to their properties. Until this is fixed, RDD operations like subtract will not give the results you expect.
Fortunately, this is usually easy to fix in Scala/Spark - define your class as a case class. This automatically generates equals and hashcode and toString methods derived from all of the properties of the class. For example:
case class Data_Object(id:String, label:String, vector:Vector)
If you want to compare your objects according to only some of the properties, you'll have to define your own equals and hashcode methods, though. See Programming in Scala, for example.
In an interface method I want to have a collection of SomeType as an input parameter. How do I represent that within a Class Diagram in EA?
I tried using "SomeType[]" as parameter type, but EA doesn't seem to keep track of this: for instance when I rename the class SomeType to something else, the change doesn't propagate here.
You can specify multiplicity for each parameter of your method.
Parameter multiplicity is not directly visible in the class diagram even if you select "Full detail" in Parameter visibility in Diagram properties. But it is in the model.
The answer is unfortunately: you can't. EA does store the name only and not the reference to the class when you specify a parameter. There are other places where that's also the case (I currently can't recall where). So if you need to track that you need to write a smart SQL to list the used parameters.
Such a SQL could look like:
SELECT * FROM t_operationparams where Type = '<Search Term>'
So, I have a core expression. It has a with element that retrieves my variable (successfully). Say my variable is of type java.awt.Point; thus it has two public properties, x and y. Is there any way to test against these properties in a core expression?
If there was some way I could provide my own implementation of org.eclipse.core.expressions.Expression, that would work. Is that possible?
I think you can do this by creating a propertyTester that would react properly to your variable using your custom code.
I have a little bit of a curve ball for you. Maybe just a design issue...maybe even something as simple as me not understanding Data annotation providers.
Anyway here we go:
I have a class which represents some model data. Let's say it represents a package/box/carton.
It actually represents all of these things so I use the class in several different views. Sometimes I want the attribute of the field Package_Description to be
So that it shows up as Box Number : input box here.
Now if i want it to appear as "Carton Name" my only option would be to sub type it. Or use a separate class to have the annotations for this class. My quandary is that some of the field names are user configurable and therefore I cannot have a static definition!
(By the way i am using third party librarys [Telerik MVC Grid] do display these field names so i cannot change the fact that it's looking at data annotation )
So I just need to know is there a way to add attributes dynamically?
Create an anonymous type on the fly, sub class the original and then add attributes using reflection?
Or what other options are open to me, do I need to somehow implement a different annotation provider?
Attributes are part of the definition of the type. Because of that, you can't modify attributes of existing classes during runtime.
You could create a new type during runtime (not an anonymous type), but I think that's not such a good idea. I'm sure whatever component you're using, it allows you to specify the appearance explicitly.