Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 7 years ago.
Improve this question
I have common methods written in different classes, making code duplicate and now to avoid this duplicacy, I am thinking of 2 approaches:
Make static methods in some util class and call them, or
Make a super class and write all these methods in super class and extend each class with this super class.
Definitely, with approach 2, I will loose the ability to extend my class further. So I am thinking to go with approach 1.
Can you please help me in identifying which approach is good and also in suggesting better approach, if you have any?
Creating Utility packages and/or class is a common solution to this problem. Apache Commons is a prime example. I would favour approach 1
Related
Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 8 months ago.
Improve this question
While using streams, I learned how to handle exceptions using functional interfaces and wrapper functions.
If so, what is the best way to structure the package?
Is it defined together in the class where stream is used? Or should I create a separate common class and define the wrapper function in it?
Thanks!
I think it depends. If you have one instance of using this technique, then it probably makes sense to simply use an functional interface and a wrap function that are part of the class which utilizes it. If you are using this same pattern in several places (and they all have the same function interface signature) then you can define the functional interface at the package level and put the wrap function in a utility class.
Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 1 year ago.
Improve this question
Where is preferred place to store functions for improve readibility of streams?
For example:
private BinaryOperator<Cash> sumPayments() {
return (payment1, payment2) -> payment1.sum(payment2);
}
I'm not sure if it should be in service class where it's used, but maybe it will be in many places so whats about some extra static Utils? or in entity?
Where possible avoid unnecessary helper methods.
In this particular example, the helper method can easily be replaced with a method reference, which is (arguably more) readable:
Cash total = subtotals.stream().reduce(Cash.ZERO, Cash::sum);
In other cases, where you actually do need a helper: think about where you would search for such a helper method in a year, when you have to adapt your now-barely-familiar code to new requirements.
Is it more entity related? Put it in the entity class
Is it more business logic related? Put it into the business logic
Is it generally useful? Put it into a utility class
Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 7 years ago.
Improve this question
I'm struggling with a naming issue. What name would you give to an interface that have just one method with this signature:
public interface ?
{
boolean isAvailable();
}
Many classes in my application can implement this interface.
Not that it really matters, you can rename it any time afterwards, and with current IDEs, it is really easy to type any name using autocomplete...
That said, if you want it short, use Available, if you want it more self-explanatory, use CanBeAvailable.
Given that the word "available" already ends with "-able", I think it's okay to break with the Java interface naming convention and call it Availability. Another approach, suggested in Programmers, is to use the prefix "Can-", in which case you can call your interface CanBeAvailable.
The below are the standards defined for Naming conventions.
Class - Always be a Noun
Interface - Always be an Adjective
Method - should be a verb
So, think of some adjective which describes the purpose of your interface.
Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 8 years ago.
Improve this question
hi what is the actual meaning of utility function in java?
The term utility function was used by Joshua Bloch in the book Effective Java to describe the methods on classes such as Arrays, Objects and Math.
The approach predates Java, and is defined by Wikipedia - Utility Class as a set of methods that perform common, often reused functions. I would go on to also point out that the functions tend to require no Object level state, that is they tend to be global functions. And that is why, in Java they tend to become implemented as static methods on a container class. As that way there is no need to instantiate the class first, and it implies through convention that the method should not have any side effects. Of course counter examples of this probably exist, but not to my knowledge within the Java Core libraries.
Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 8 years ago.
Improve this question
I am having trouble in understanding the meaning of "Abstraction in Java". I googled, and studied books, in those I got two types of definitions.
Choosing necessary properties and hiding unwanted details is Abstraction.
Abstraction is the concept of simplifying one idea to a more general, overhead idea.
I feel above two definitions don't mean same, and are entirely different.
So which is correct one?
I think both your statement have same meaning if you think deeply.
Hiding necessary properties and hiding unwanted details leads you to more general, overhead idea.
suppose Animal is a abstract class we hide the nature of animal and their food habits in abstract class and when we talk about Tiger we introduce all the revelant details,
Abstraction is hiding of data.
Means IF you have a class A which contain 2 variables suppose int id,String name
in which if you want to keep that data protected in your class you will keep
Id as private variable so your variable is not directly accessible outside class.
This way you can approach to handle abstraction in class.