Is it good to use inner class in Java?

Inner classes are used to get functionality which can get an object better than method. They can be used in the case when a set of multiple operations are required and chances of reusability are good inside the class and they will not be accessed but methods outside the outer class.

What is a reason to use an inner class?

Compelling reasons for using nested classes include the following: It is a way of logically grouping classes that are only used in one place. It increases encapsulation. It can lead to more readable and maintainable code.

Is inner class thread safe in Java?

5 Answers. In essence, doing public static class X on a nested inner-class is the same as doing public class X in a standard top-level class. There is no meaning to a “class” itself being thread-safe or not thread safe. Therefore, whether or not it is static is irrelevant.

Should nested classes be avoided?

In general we should avoid using inner classes. Use inner class only when an inner class is only relevant in the context of the outer class and/or inner class can be made private so that only outer class can access it.

Is inner class a good practice?

Any additional encapsulation, such as making the entire inner class private , is desirable; but public inner classes are perfectly acceptable. There are many examples in Java, such as AbstractMap.

Why do we need static inner classes in Java?

The Java programming language allows you to define a class within another class. Non-static nested classes (inner classes) have access to other members of the enclosing class, even if they are declared private. Static nested classes do not have access to other members of the enclosing class.

Why is static inner class singleton thread safe?

Here we are assigning within a static initialiser (of SingletonHolder ), which will be seen by any thread accessing it with correct happens-before relationship. There’s nothing really special about the nested class, it just allows the outer class to be used without immediately constructing the singleton object.

When should I use nested class?

There are several reasons for using nested classes, among them:

1. It is a way of logically grouping classes that are only used in one place.
2. It increases encapsulation.
3. Nested classes can lead to more readable and maintainable code.

Should I use nested classes?

There are several reasons for using nested classes, among them: It is a way of logically grouping classes that are only used in one place. It increases encapsulation. Nested classes can lead to more readable and maintainable code.

What is the advantage of static inner class?

The advantage of a static nested class is that it doesn’t need an object of the containing class to work. This can help you to reduce the number of objects your application creates at runtime. It’s called a nested class. All nested classes are implicitly static; if they are not static they are called inner classes.

Should static classes be inner?

An inner class, by default, has an implicit reference to an object of the outer class. If you instantiate an object of this from the code of the outer class, this is all done for you. As a basic rule, if the inner class has no reason to access the outer one, you should make it static by default.

Is static inner class thread safe?

We know static variables are not thread safe.

What is the use of inner class in Java?

Inner classes are a security mechanism in Java. We know a class cannot be associated with the access modifier private, but if we have the class as a member of other class, then the inner class can be made private. And this is also used to access the private members of a class.

How to get private members of an inner class in Java?

Write an inner class in it, return the private members from a method within the inner class, say, getValue(), and finally from another class (from which you want to access the private members) call the getValue() method of the inner class.

Are inner classes really that bad?

Inner classes are frequently used, and something very similar – anonymous classes – are practically indispensable, as they are the closest thing Java has to closures. So if you can’t remember where you heard that inner classes are bad, try to forget about it! They’re not “bad” as such.

What are anonymous inner classes in Java?

An inner class declared without a class name is known as an anonymous inner class. In case of anonymous inner classes, we declare and instantiate them at the same time. Generally, they are used whenever you need to override the method of a class or an interface. The syntax of an anonymous inner class is as follows −.