Differences between Java records and classes

Java records and classes serve different purposes and have distinct characteristics. Here are the key differences between Java records and classes:

Java Records:

  • Introduced in Java 14 as a preview feature and became a standard feature in Java 16.
  • Designed specifically for modeling immutable data.
  • Provide a concise syntax to declare classes with a fixed set of properties (components).
  • Automatically generate implementations for constructors, accessors (getters), equals(), hashCode(), and toString() methods based on the defined components.
  • Records are implicitly final and cannot be extended.
  • Records cannot define additional methods or have static fields.
  • Records support private fields and constructors, but they are generally used for immutable objects.
  • Records can be nested within other classes.
  • Records can implement interfaces and inherit from other classes.
  • Records can define their own instance methods and static methods.
  • Records are suitable for use cases where data immutability and automatic generation of common methods are desired, such as DTOs, data models, or simple data containers.

Java Classes:

  • The traditional and most common way of defining custom types in Java.
  • Provide full control over the class structure and behavior.
  • Require manual implementation of constructors, accessors, equals(), hashCode(), and toString() methods.
  • Classes can be extended and serve as base classes for inheritance.
  • Classes can define additional methods and have static fields.
  • Classes can have mutable fields and mutable behavior.
  • Classes can be nested within other classes.
  • Classes can implement interfaces and inherit from other classes.
  • Classes offer more flexibility and are suitable for complex business logic, object-oriented design patterns, or scenarios where custom behavior and mutability are required.

In summary, Java records are specifically designed for modeling immutable data and provide a concise syntax with automatic generation of common methods. They are suitable for scenarios where data immutability and simplicity are desired. On the other hand, Java classes offer full control over the class structure, behavior, and mutability, making them suitable for a wide range of use cases, including complex business logic and object-oriented design patterns.