Home Java javaTutorial Why Does Java Prohibit Calling a Superclass's Superclass Method (super.super.method())?

Why Does Java Prohibit Calling a Superclass's Superclass Method (super.super.method())?

Dec 31, 2024 pm 01:25 PM

Why Does Java Prohibit Calling a Superclass's Superclass Method (super.super.method())?

Calling Super's Super Method in Java: Why is it Prohibited?

Despite the ease with which one might circumvent certain scenarios by accessing the parent's parent's method directly using super.super.method(), Java forbids such invocation. This article explores the reasons behind this restriction and discusses whether analogous mechanisms exist in other languages.

Encapsulation Violation

The primary reason Java disallows super.super.method() is to uphold encapsulation. This principle prevents the bypass of a parent class's behavior by accessing its superclass directly. While bypassing one's own class's behavior may occasionally be necessary, such as from within the same method, it should not be possible for the subclasses to bypass the behavior of their parents.

Example: Maintaining Class Invariants

Consider a hierarchy of classes: Items, RedItems, and BigRedItems. Items represents a collection of items, RedItems a collection of red items, and BigRedItems a collection of big red items. To maintain the integrity of each class:

public class Items {
    public void add(Item item) { ... }
}

public class RedItems extends Items {
    @Override
    public void add(Item item) {
        if (!item.isRed()) {
            throw new NotRedItemException();
        }
        super.add(item);
    }
}

public class BigRedItems extends RedItems {
    @Override
    public void add(Item item) {
        if (!item.isBig()) {
            throw new NotBigItemException();
        }
        super.add(item);
    }
}
Copy after login

This ensures that RedItems contains only red items and BigRedItems contains only big red items.

Breaking the Encapsulation Contract

If super.super.add() were permitted:

public class NaughtyItems extends RedItems {
    @Override
    public void add(Item item) {
        // Add any item to NaughtyItems, ignoring the rule in RedItems
        super.super.add(item);
    }
}
Copy after login

NaughtyItems could bypass the invariant in RedItems, adding items indiscriminately, rendering the encapsulation of RedItems meaningless.

Conclusion

The prohibition of super.super.method() in Java is an important safeguard that prevents encapsulation violation, maintaining the integrity and consistency of class hierarchies. While it may prevent certain convenient scenarios, it ensures the robustness and reliability of Java codebases.

The above is the detailed content of Why Does Java Prohibit Calling a Superclass's Superclass Method (super.super.method())?. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Is the company's security software causing the application to fail to run? How to troubleshoot and solve it? Is the company's security software causing the application to fail to run? How to troubleshoot and solve it? Apr 19, 2025 pm 04:51 PM

Troubleshooting and solutions to the company's security software that causes some applications to not function properly. Many companies will deploy security software in order to ensure internal network security. ...

How to simplify field mapping issues in system docking using MapStruct? How to simplify field mapping issues in system docking using MapStruct? Apr 19, 2025 pm 06:21 PM

Field mapping processing in system docking often encounters a difficult problem when performing system docking: how to effectively map the interface fields of system A...

How to elegantly obtain entity class variable names to build database query conditions? How to elegantly obtain entity class variable names to build database query conditions? Apr 19, 2025 pm 11:42 PM

When using MyBatis-Plus or other ORM frameworks for database operations, it is often necessary to construct query conditions based on the attribute name of the entity class. If you manually every time...

How does IntelliJ IDEA identify the port number of a Spring Boot project without outputting a log? How does IntelliJ IDEA identify the port number of a Spring Boot project without outputting a log? Apr 19, 2025 pm 11:45 PM

Start Spring using IntelliJIDEAUltimate version...

How do I convert names to numbers to implement sorting and maintain consistency in groups? How do I convert names to numbers to implement sorting and maintain consistency in groups? Apr 19, 2025 pm 11:30 PM

Solutions to convert names to numbers to implement sorting In many application scenarios, users may need to sort in groups, especially in one...

How to safely convert Java objects to arrays? How to safely convert Java objects to arrays? Apr 19, 2025 pm 11:33 PM

Conversion of Java Objects and Arrays: In-depth discussion of the risks and correct methods of cast type conversion Many Java beginners will encounter the conversion of an object into an array...

E-commerce platform SKU and SPU database design: How to take into account both user-defined attributes and attributeless products? E-commerce platform SKU and SPU database design: How to take into account both user-defined attributes and attributeless products? Apr 19, 2025 pm 11:27 PM

Detailed explanation of the design of SKU and SPU tables on e-commerce platforms This article will discuss the database design issues of SKU and SPU in e-commerce platforms, especially how to deal with user-defined sales...

How to elegantly get entity class variable name building query conditions when using TKMyBatis for database query? How to elegantly get entity class variable name building query conditions when using TKMyBatis for database query? Apr 19, 2025 pm 09:51 PM

When using TKMyBatis for database queries, how to gracefully get entity class variable names to build query conditions is a common problem. This article will pin...

See all articles