How to create a generic class in Java?
In Java, you can create a generic class by declaring one or more type parameters within angle brackets (<>) when defining the class. These type parameters act as placeholders for actual types that are provided when using the generic. Generics allow you to create classes that can work with any data type in a type-safe manner.

Table of Contents
Explanation
1. Type Parameters
When defining a generic class, you specify one or more type parameters within angle brackets (<>). These type parameters represent the types that the generic will operate on. You can use any valid Java identifier as a type parameter.
2. Type-Safe Operations
Generic classes enable you to perform type-safe operations on different data types without the need for explicit type casting. The compiler ensures that only the specified types are used with the class, thereby preventing type-related errors at compile time.
3. Code Reusability
Generic promote code reusability by allowing you to write classes that can work with any data type. This eliminates the need for writing duplicate code for each specific type and increases the flexibility and versatility of your codebase.
java
// Generic class definition with a single type parameter T
public class Box<T> {
private T value;
// Constructor to initialize the value of type T
public Box(T value) {
this.value = value;
}
// Getter method to retrieve the value of type T
public T getValue() {
return value;
}
// Setter method to set the value of type T
public void setValue(T value) {
this.value = value;
}
// Method to print the details of the box
public void printDetails() {
System.out.println("Box contains: " + value);
}
// Example of a generic method in a generic class
public <U> void performOperation(U input) {
// Perform some operation using the input
System.out.println("Performed operation with input: " + input);
}
}
In this example, Box is a generic class with a single type parameter T. The class contains a private member variable value of type T, along with getter and setter methods to access and modify the value. The class also includes a generic method performOperation() that demonstrates how generic methods can be defined within a generic class. This Box class can be instantiated with any data type, allowing it to hold and operate on values of different types in a type-safe manner.