Can we call class with setter and getter as Java Bean? [duplicate] - java

This question already has answers here:
What is a JavaBean exactly?
(23 answers)
Closed 6 years ago.
In bean standards, it is mentioned that it must implement serializable.
But in general developers say to create beans which means simple setter/getter.
Is bean correct terminology or any other terminology for class with setter and getter methods?

I think it's just called a class that follows Object Oriented Programming (OOP) principles when you use getters and setters and make the fields private.
http://codebetter.com/raymondlewallen/2005/07/19/4-major-principles-of-object-oriented-programming/

Related

How can you access a private method with dependency injection in a Spring app? [duplicate]

This question already has answers here:
Any way to Invoke a private method?
(6 answers)
Closed 3 years ago.
Using the #Autowired annotation, I've managed to succesfully call the methods i needed from another class, however not all of them, since some methods are private.
Is it possible to call them without making them public? How?
You cannot do that. Dependency injection is just a trick, that takes handling of interfaces and implementations from developer. Framework is doing that for you. The resulting object has same properties as if it was created using new keyword.

Concept of encapsulation [duplicate]

This question already has answers here:
Simple way to understand Encapsulation and Abstraction
(16 answers)
Java Encapsulation Concept not clear
(12 answers)
Closed 4 years ago.
Concept of encapsulation:If we can change the value of private variable indirectly(through setters and getters), then how is the private variable secured, how is it hidden?Could someone please explain in detail..
You're correct. If a field is exposed via getters and setters, it is not encapsulated. It's annoying how many people don't understand this so it's not surprising that you're confused.
Check out this answer. Essentially, using the keyword private we are able to prevent outside use of the fields in a class, for example. It hides the data in a class associated with that private keyword.

why to use interface if there is only abstract methods [duplicate]

This question already has answers here:
Do/can abstract classes replace interfaces? [duplicate]
(11 answers)
what is the actual use of interface in java? [duplicate]
(6 answers)
Closed 7 years ago.
In java there is interface which having only abstract method means method declration only and those methods are implement in class that implement interface so why to use interface which has only declaration .This question is asked in interview.
Interfaces are used for only declaration of methods because it can achieve multiple behavior. It is the class's responsibility to implement the interfaces and define their methods as they desire.
Interfaces allow same methods to be implemented in different manner by implementing classes, which allows you to achieve behavioral facility.
For understanding sake, you can consider interfaces exist so you can achieve behavioral approach for your application, and class exist to achieve characteristic approach.

Why is the System class declared as "final" in Java? [duplicate]

This question already has answers here:
Java -- private constructor vs final and more
(3 answers)
Closed 7 years ago.
As per my understanding, a class is declared as final to prevent it from being extended/inherited. So I see there can be security and probably some performance gains in this regard.
But is there a very specific design decision behind this? Say for eg: to realize some kind of design pattern? I did go around a similar thread here! but the answer was not really what I was looking for
Singleton Pattern:
-Private Constructor
-Only static methods
-No need to have more than one object of this class or an object at all
-No need to extend this fundamental class

About Java Bean [duplicate]

This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
What is a Java Bean exactly?
This is a simple question about Java Bean, there is some restriction in the type of classe? For example, a bean can be a abstract class ?
Thanks
A JavaBean class is a class which respects a number of conventions. But depending on the usage of the class, some conventions are or aren't important. In the strict sense, a JavaBean class
must have a public no-arg constructor allowing to instantiate it
must have properties available through getters and setters
must be serializable
So, in the strict sense, a JavaBean class may not be abstract. But an abstract class can be the superclass of a JavaBean class.

Categories