Static Classes in Java
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In this article, we are going to study what is a static class in Java and how we can create it. Later, we will discuss some implementation considerations and benefits of using a static class.
Before starting our tutorial on the static class, we first want to briefly remind you that "What is static?", Static is a keyword that can be used with class, variable, method, and block to create static members. Static members belong to the class instead of a specific instance, this means if you make a member static, .you can access it without an object.
A static member can be:
- static variables,
- static methods,
- static block or static initialization block, and,
- static class
Static classes are basically a way of grouping classes together in Java. Java doesn't allow you to create top-level static classes; only nested (inner) classes. For this reason, a static class is also known as a static inner class or static nested class. Let's have a look at how to define a static class in java. Let's have a look at how to define a static class in Java.
Points to be considered while writing a static class
- It can only be a nested or inner class only.
- It can have any access modifier (private, protected, public, or default) like any other static member.
- It can only access the static members of its enclosing class.
- It cannot access the non-static members of its enclosing class directly. It can interact with the non-static member only through the object of its enclosing class only.
Benefits of Static class in java
- We can define the related or helper classes inside the class by making it static.
- It can access the private member of the enclosing class through the object reference.
- It provides a nice namespace for the nested class.
- If the enclosing class gets updated, we are able to update the static class as well at the same location.
- Classloader loads the static class in JVM only at the time of the first usage, not when its enclosing class gets loaded.
In this article, we have studied what is a static class in java, how to create it and its benefits. We have created a User with UserValidator class to provide the facility to check whether it is a valid user or not. It is good to have helper classes as a static class inside the enclosing class.
Published at DZone with permission of Shubham Bansal. See the original article here.
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