How to generate interface's methods into all implementation classes? - java

I am looking for some kind of refactoring feature in Eclipse to generate methods in implementation classes from an interface class. Let's say I have JavaClassImpl1 and JavaClassImpl2, which implement JavaClassInterface. What I'd like to do is when I add a method to JavaClassInterface, the refactoring option is to generate empty methods in all implementation classes, in this case, in JavaClassImpl1 and JavaClassImpl2.

If you haven't implemented all of the required methods in eclipse, it will show a bunch of compile-time errors in your class (the class will have a red underline).
If you hover over the class name, a pop-up will appear with available quick fixes, one of which will be Add unimplemented methods. If you select that eclipse will generate a stub for each unimplemented method.
Another way to access the same function is to rightclick in your class and select Source -> Override/Implement Methods... which will pop up a wizard which allows you to select which methods you would like eclipse to stub out for you.
Update
If the change you make to your interface is done via one of the eclipse refactor tools, then eclipse will generally update references to the thing that was changed. For instance, if you do a Refactor -> Introduce Parameter Object... on a method in your interface, then eclipse will automatically update implementing methods.
If you're adding code manually, eclipse doesn't even know about the change until the next time you compile, and you'll have to explicitly ask eclipse to refactor the code.

Related

Not getting "Add unimplemented methods" error in eclipse

I am working on Selenium with Java and using Listeners.
I created the class, imported the TestNG, and then added method as;
Public class Listener implements ITestListener{
}
I got an error at "ITestListner" and then imported "ITestListner(org.testng). After this it was expected that I will get an error for "Listener" but I didn't get any error.
I tried creating with abstract class but still didn't get the error.
package com.testng;
import org.testng.ITestListener;
public class Listeners implements ITestListener{
}
The expectation is when I move the cursor over "Listeners" I should get "Add unimplemented methods" option.
Right click(on the Listeners class ) -> go to source-> click on overide/implement methods -> select the check boxes for the ITest listener (make sure all check box inside it should be checked )->click on oK. That's it !!!
As i got to know from the below link - TestNG 7.0.0 uses JDK8 and with it default methods within interfaces. What this means is that every listener would now have a default implementation (which doesn't do anything ) for all methods defined within the interface.
So now you won't see those indications from the IDE. The biggest benefit of default methods in interfaces is that let's say you are implementing an interface that has 10 methods defined in it, you can just implement whatever you need and the rest of the behavior comes via the default methods in the interface.
Reference-
https://github.com/cbeust/testng/issues/1964
Right click on the class --> select source --> choose override/implement methods --> then pick the methods you'd like to implement.
Try downgrading the TestNg version to 6.14.3.
It worked for me.
The Best solution is go to the source tab besides the File-Edit options and click the Overide/implement methods and you are set
All methods in ITestListener interface changed to default from 7 version onwards. You can call them with class object where you implemented interface.

Eclipse: When displaying a list of methods (ctrl-space), is there a way to have methods in that class - bold?

Eclipse:
When displaying a list of methods (ctrl-space), is there a way to have methods found in that class have names in bold? Netbeans has or at least had a feature that would bold the names of methods found within that class while inherited methods remained normal text.
This made it very easy to know what methods are from within the class you are editing.
Is there a way to do this in the latest version of Eclipse?
Thanks.
It seems eclipse does not support it.
What I do in such cases (workaround):
Open the affected class (Navigate -> Open Type...)
Press CTRL-O, this will show the methods implemented in this class.
Press CTRL-O again, this will also show the inherited methods.

How to display java classes in eclipse calling a method from other class

I was wondering if there is a quick way of identifying or displaying which classes are trying to call a method.
Its easy to do this if there are only few classes present. But what if there are hundreds of classes trying to call a method in other classes. It would be extremly tedious if I do this manually. Is there a plugin or some built-in functions that would do this in eclipse?
The reason am asking is I wanted to map out different classes that are calling methods from other classes for easy debugging.
Right click your function, select references, and then choose what you want (generally project). That will show all the references to this function in the project. This also works for classes, variables, and probably other stuff too.
You can try an eclipse's Call Hierarchy feature. It shows you all the methods which directly call the method you are interested in. You can expand each caller and see what methods call it and so on.
You can do it buy right clicking on the method and selecting an "Open Call Hierarchy" menu item or pressing Ctrl+Alt+H Hotkey.

How do I add methods and attributes using ObjectAid?

My goal is to add methods and attributes to the class diagram to make it generate stubs of code in the classes.
Here's an example:
If I'm just starting a project. I have a class called tuna and I want to add the methods swim(), eat() and poop() with it generating stubs. This way by the time I'm done with all the classes and start to code I won't forget what I was thinking.
Could ObjectAid be the wrong tool for the job?
ObjectAid can only show you the source code, you have to go to an editor to change it. When you double-click on a class, method or field, an editor will open at the proper location.

Can eclipse convert/refactor a method to a class?

This seems like it should be fairly straight-forward, but I can't see anything obvious. What I basically want to do it to point at a method and refactor->extract class. This would take the method in question to a new class with that method as top level public API. The refactoring would also drag any required methods and variables along with it to the new class, deleting them from the old class if nothing else in the old class is using it.
This is a repetitive task I often encounter when refactoring legacy code. Anyway, I'm currently using Eclipse 3.0.2, but would still be interested in the answer if its available in a more recent version of eclipse. Thanks!
I don't think this kind of refactoring exists yet.
Bug 225716 has been log for that kind of feature (since early 2008).
Bug 312347 would also be a good implementation of such a refactoring.
"Create a new class and move the relevant fields and methods from the old class into the new class."
I mention a workaround in this SO answer.
In Eclipse 3.7.1 there is an option to move methods and fields out of a class. To do so:
Make sure the destination class exists (empty class is fine, just as long as it exists in the project).
In the source class, select the methods that you want to remove (the outline view works great for this), right click on the selection, and choose Move
Select the destination class in the drop down/Browse
Your members are now extracted. Fix any visibility issues (Source > Generate Getters and Setters is very useful for this) and you are all set.
This seems like it should be fairly
straight-forward...
Actually, Extract Class is one of the more difficult refactorings. Even in your simple example of moving a single method and its dependencies, there are possible complications:
If the moved method might be used in code you don't know about, you need to have a proxy method in the original class that will delegate to (call) the moved method. (If your application is self-contained or if you know all the clients of the moved method, then the refactoring code could update the calling code.)
If the moved method is part of an interface or if the moved method is inherited, then you will also need to have a "proxy method".
Your method may call a private method/field that some other method calls. You need to choose a class for the called member (maybe in the class that uses it the most). You will need to change access from "private" to something more general.
Depending on how much the original class and the extracted class need to know about each other, one or both may need to have fields initialized that point to the other.
Etc.
This is why I encourage everybody to vote for bug 312347 to get fixed.
Have you tried the Move feature of the Refactor group ? You can create a helper class and move there anything you want.

Categories