What Are the Differences Between Public Interfaces and Published Interfaces in Java?

What are the differences between public interfaces and published interfaces in Java?

In Java, the terms 'public interfaces' and 'published interfaces' refer to two distinct concepts regarding interface accessibility and visibility in application development. Understanding these concepts is crucial for designing effective APIs and ensuring proper encapsulation of functionality.

public interface Vehicle { // Publicly accessible interface methods  void start();  void stop();}

// Usage in another class
public class Car implements Vehicle { 
  public void start() { System.out.println("Car starting"); }  
  public void stop() { System.out.println("Car stopping"); }}

Causes

• Public interfaces are explicitly defined in Java code with the 'public' access modifier, indicating that they can be accessed from any other class or package.
• Published interfaces, on the other hand, refer to interfaces that are intended for public use but may not be explicitly defined as 'public' in every context, as they could be part of a library or framework that users depend on.

Solutions

• When defining interfaces in Java, utilize the 'public' keyword to ensure the interface is accessible wherever required.
• For published interfaces, ensure that documentation clearly states the intended use and versioning to inform users of any changes.

Mistake: Using package-private interfaces when public accessibility is needed.

Solution: Always assess the needs of your application and use 'public' for interfaces intended for external use.

Mistake: Failing to document changes in published interfaces, leading to confusion.

Solution: Maintain clear versioning and changelogs to inform users of any modifications.