0
votes
1answer
69 views

Prepared statement alternatives for this middle-man program?

I have an program that is using a prepared statement to connect and write to a database working nicely, and now need to create a middle-man program to insert between this program and the database. ...
0
votes
1answer
112 views

How to generalize a classes that has identical function plus some additional function

I have some designing problems with my project. To illustrate my problem, I'll use the following two classes from my project. public class RAM_UserManagement{ private Map<int,User> userList; ...
39
votes
9answers
4k views

Programming for future use of interfaces

I have a colleague sitting next to me who designed an interface like this: public interface IEventGetter { public List<FooType> getFooList(String fooName, Date start, Date end) ...
0
votes
3answers
288 views

Why do APIs generally consist of interfaces? [duplicate]

I am starting out in Java API design and in reading existing code bases, I have found that most APIs consist of interfaces only with their implementations bundled in a different package. Having read ...
0
votes
2answers
140 views

Java best practice Interface - subclasses and constants

In the case where a couple of classes implements an interface, and those classes have a couple of constants in common (but no functions), were should I put this constant ? I've had this problem a ...
0
votes
2answers
143 views

Is using interfaces on internal code a good idea? [duplicate]

I'm working on a set of automated tests that we use internally at work. Lately, we've been designing classes that implement interfaces in addition to inheritance. As I understand it, interfaces in ...
7
votes
2answers
268 views

How to hide AOP implementation dependency without breaking encapsulation?

I have the concept of a SlowLoading thing: public interface SlowLoading { boolean hasLoaded(); } I also have a component MyComponent: public interface myComponent{ void doSomething(); } My ...
1
vote
3answers
138 views

Empty superclass for Collection of derived classes

Basically, what I would like to obtain is a way to iterate through ONE list, and call methods specific to the interface the objects in the collection implement. In my Java project, it would result in ...
0
votes
1answer
94 views

Can a Java interface declaration enforce parameter properties?

As far as I know, declaring an interface is like so: public interface Roots_Squares { public double square_root( double value ); } Now... how do you enforce value to have non-negative values? ...
45
votes
10answers
5k views

Is better Show() + Hide() or SetVisible(bool visible)?

What is better and why? (From interface-design point of view) : a) To have two Show() and Hide() functions b) To have one SetVisible(bool visible) function EDIT: For example some object have ...
6
votes
3answers
3k views

Why were default and static methods added to interfaces in Java 8 when we already had abstract classes?

In Java 8, interfaces can contain implemented methods, static methods, and the so-called "default" methods (which the implementing classes do not need to override). In my (probably naive) view, there ...
0
votes
0answers
49 views

Use Objective-C protocols like Java interfaces [duplicate]

I'm a Java developer moving to Objective-C. So far in Objective-C I've seen protocols used extensively to implement the delegate pattern, but I haven't seen then to add a layer of abstraction in the ...
25
votes
2answers
2k views

What is the name of the following (anti) pattern? What are its advantages and disadvantages?

Over the last few months, I stumbled a few times over the following technique / pattern. However, I can't seem to find a specific name, nor am I a 100% sure about all its advantages and disadvantages. ...
-3
votes
3answers
496 views

Programming to interface in Java [duplicate]

What is the real use of interfaces in Java? What is meant by programming to interfaces? I heard these things several times but I don't know what it is and why it is used.
1
vote
4answers
544 views

Explanation of the definition of interface inheritance as described in GoF book

I am reading the first chapter of the Gof book. Section 1.6 discusses about class vs interface inheritance: Class versus Interface Inheritance It's important to understand the difference between ...
3
votes
2answers
675 views

Collection interfaces in C#, coming from Java

In Java, I'm used to declaring collections using the most-abstract interface possible and then constructing them using the concrete implementation that makes sense at the time. It usually looks ...
1
vote
1answer
130 views

How do you distinguish your public API interfaces from the interfaces you use for testing/mocking?

Mocking frameworks are useful for creating mock objects that isolate the code under test from its surrounding software environment. Some mocking frameworks cannot mock non-virtual methods, so they ...
31
votes
4answers
3k views

What did Rich Hickey mean when he said, “All that specificity [of interfaces/classes/types] kills your reuse!”

In Rich Hickey's thought-provoking goto conference keynote "The Value of Values" at 29 minutes he's talking about the overhead of a language like Java and makes a statement like, "All those interfaces ...
1
vote
5answers
755 views

The need for adding an interface to every class [duplicate]

My coworker and I are arguing very hard about this topic. He's thinking that every single class should have an Interface that the class implements (also Single-Implementations). He uses this design ...
4
votes
2answers
219 views

Should I make package private my DAO interfaces?

I have several DAO classes that implement an interface. In the other hand, I have Service classes that use those DAO implementations. So far all the DAO interfaces are public and I was thinking if ...
5
votes
1answer
246 views

Why aren't there Dimension and Point interfaces?

I mean something along the lines of: public interface Dimensioned { int getWidth(); int getHeight(); } and public interface Positioned { int getX(); int getY(); } There are a ...
8
votes
3answers
2k views

Should I implement an interface directly or have the superclass do it?

Is there a difference between public class A extends AbstractB implements C {...} versus... public class A extends AbstractB {...} AbstractB implements C {...} I understand that in both cases, ...
5
votes
2answers
675 views

How to create contracts in python

I am currently learning Python (from Java) and have a question on contracts. Example: an application defines an interface that all plugins must implement and then the main application can call it. ...
0
votes
0answers
136 views

Where are the Interface information stored?

I would like to know whether the information in an interface such as the variables which are final and the methods which are abstract and static would all live in method area ??? And what would be ...
6
votes
5answers
422 views

Everything has an Interface [duplicate]

Possible Duplicate: Do I need to use an interface when only one class will ever implement it? I am taking over a project where every single real class is implementing an Interface. The ...
1
vote
2answers
1k views

Java - What methods to put in an interface and what to keep out

I'm designing a file handler interface: public interface FileHandler { public void openFileHandler(String fileName); public void closeFileHandler(); public String readLine(); public ...
2
votes
1answer
538 views

Why this code create object as interface?

In am reading Spring in Action (3rd edition) and here a snippet from it: ApplicationContext ctx=new ClassPathXmlApplicationContext("springidol.xml"); Performer ...
13
votes
4answers
900 views

Is there a different usage rationale for abstract classes/interfaces in C++ and Java

According to Herb Sutter one should prefer abstract interfaces (all pure virtual functions) to abstract classes in C++ to decouple the implementation as far as possible. While I personally find this ...
8
votes
9answers
1k views

What OO Design to use ( is there a Design Pattern )?

I have two objects that represent a 'Bar/Club' ( a place where you drink/socialise). In one scenario I need the bar name, address, distance, slogon In another scenario I need the bar name, address, ...
37
votes
6answers
7k views

What is the point of having every service class have an interface? [duplicate]

At the company I work at, every service class has a corresponding interface. Is this necessarily? Most of these interfaces are only used by a single class and we are not creating any sort of public ...
1
vote
6answers
407 views

Interfaces: profit of using

First of all, my ubiquitous language is PHP, and I'm thinking about learning Java. So let me split my question on two closely related parts. Here goes the first part. Say I have a domain-model ...
1
vote
4answers
2k views

Teaching java interfaces to absolute beginners: What is a good example? [duplicate]

Possible Duplicate: Explaining interfaces to beginning programmers? I searched on stackoverflow and here for a good example to teach java interfaces in a beginners class. I found the ...
9
votes
4answers
7k views

Who extends interfaces? And why?

AFAIK, my class extends parent classes and implements interfaces. But I run across a situation, where I can't use implements SomeInterface. It is the declaration of a generic types. For example: ...
12
votes
8answers
5k views

What is the point of an interface? [duplicate]

Possible Duplicate: When to use abstract classes instead of interfaces and extension methods in C#? What other reasons are there to write interfaces rather than abstract classes? This ...
1
vote
2answers
2k views

What other reasons are there to write interfaces rather than abstract classes? [duplicate]

Possible Duplicate: When to use abstract classes instead of interfaces and extension methods in C#? When I read and looked at codes using Abstract classes, I was able to justify it because ...
10
votes
3answers
726 views

How do existential types differ from interfaces?

Given the existential type T = ∃X.{op₁:X, op₂:X→boolean} and this generic Java interface: interface T<X> { X op₁(); boolean op₂(X something); } What are the fundamental differences ...
-5
votes
4answers
2k views

What is Interface in Java programming language? [duplicate]

Last week my lecturer was teaching us about interfaces in Java. However, I failed to understand her explanation that well. Does anyone have a good description, or explanation of Java interfaces, and ...
5
votes
2answers
3k views

What is the proper way to implement the OnClickListener interface for many buttons

My Android Activity contains multiple buttons that all need an OnClickListener. I've seen lots of different ways of doing this such as:: Implementing the interface in activity class Creating a ...
9
votes
5answers
1k views

Modified Strategy Design Pattern

I've started looking into Design Patterns recently, and one thing I'm coding would suit the Strategy pattern perfectly, except for one small difference. Essentially, some (but not all) of my ...