Encapsulation in Java Classes: Hiding Internal Details, Exposing Only Necessary Interfaces

This article introduces the core of Java encapsulation: hiding internal class details and only exposing necessary interfaces to ensure data security and logical rationality. Encapsulation is implemented through access modifiers: using `private` to hide attributes (such as a student's `name` and `age`), which cannot be directly modified from outside; exposing interfaces through `public` methods (such as `setName` and `setAge`), with logical validation added within the methods (e.g., age cannot be negative). By comparing a wrong example (directly exposing attributes leading to illegal modifications) with a correct implementation (private attributes + validated methods), encapsulation can prevent data chaos (e.g., maintaining age within a reasonable range), achieve modularization (separation of internal and external), and enhance maintainability (internal logic changes do not affect the outside). Encapsulation is a foundation of Java's object-oriented programming. By hiding details and exposing secure interfaces, it ensures code robustness and is a key factor in writing high-quality code.

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Encapsulation in C++: Hiding Attributes and Exposing Interfaces

This article focuses on C++ encapsulation, with the core principle being "hiding internal details while exposing necessary interfaces." Encapsulation is a key principle in object-oriented programming, similar to how a mobile phone can be used without understanding its internal structure. In C++, access modifiers achieve this: `private` hides a class's internal properties (default), accessible only by the class itself; `public` exposes external interfaces for external calls. The necessity of encapsulation lies in preventing data chaos. For example, if a student class directly exposes attributes like age and scores, they might be set to negative values or out-of-range values. Encapsulation addresses this by using `private` members combined with `public` interfaces, where validation logic (e.g., age must be positive) is embedded in the interfaces to ensure data security. The core benefits of encapsulation are threefold: first, data security by preventing arbitrary external modification; second, centralized logic through unified validation rules in interfaces; third, reduced coupling, as external code only needs to focus on interface calls without understanding internal implementations. In summary, encapsulation serves as a "shield" in C++ class design. By hiding details and exposing interfaces, it ensures data security while making the code modular and easy to maintain.

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Implementing MySQL Database Master-Slave Replication

This document provides a detailed introduction to how to configure Master-Slave Replication in MySQL database, accompanied by configuration steps and simple test cases. The key points summarized are as follows: ### Configuration Steps #### 1. Select servers as master and slave - Choose one MySQL server as the master and another as the slave. #### 2. Setup on the master server - First, add the following configurations to the master's `/etc/my.cnf` or `my.ini` configuration file:

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