How to use the Records class to create immutable data objects in Java 14
Introduction:
In the software development process, data objects are very important. In order to ensure data security and consistency, data objects usually need to be designed to be immutable. In Java, we can use Records class to create immutable data objects. This article will introduce how to use the Records class to create immutable data objects in Java 14 and provide corresponding code examples.
record
plus the class name and attributes. For example, the following is an example of a simple Person class: record Person(String name, int age) {}
The above code defines a Records class named Person, which has two attributes, name and age. The Records class is immutable, so we cannot modify the objects after they are created.
Person person = new Person("Alice", 25);
We can also access the properties of the Records class like the properties of a normal class:
String name = person.name(); int age = person.age();
It is worth noting that the Records class A toString()
method is automatically generated, so we can directly call the toString()
method to obtain the string representation of the object:
System.out.println(person); // 输出:Person[name=Alice, age=25]
4.1 Simplicity: Compared with the traditional class definition method, the Records class is more concise, eliminating the need for tedious code writing.
4.2 Immutability: The properties in the Records class are final and cannot be modified after they are created, ensuring the immutability of the data object.
4.3 Automatically generated methods: The Records class automatically generates some commonly used methods for us, such as equals, hashCode and toString, etc. We do not need to write these methods manually.
4.4 Easy to read and write: The Records class is clearly defined, and the properties can be obtained through simple access methods, making the code easy to understand and maintain.
5.1 Properties must be final: Properties in the Records class must be declared final , which is to ensure the immutability of data objects.
5.2 The constructor cannot be explicitly defined: The constructor of the Records class is implicitly generated, so we cannot explicitly define the constructor.
5.3 Cannot inherit other classes: The Records class cannot inherit other classes, but it can implement interfaces.
5.4 Access modifiers cannot be used on properties: Properties in the Records class are public by default, and other access modifiers cannot be used.
record
keyword and declare the properties, and the rest of the work is automatically generated by the Records class. Using the Records class can improve the readability and maintainability of your code. However, we also need to pay attention to some restrictions of the Records class, such as properties must be final, constructors cannot be explicitly defined, etc. I hope this article can help you understand and use the Records class in Java 14. The above is the detailed content of How to use Records class in Java 14 to create immutable data objects. For more information, please follow other related articles on the PHP Chinese website!