How is multiple inheritance implemented in Java?

Java does not support multiple inheritance, meaning a class cannot directly inherit from multiple parent classes. This is a restriction in Java’s design to ensure clarity and maintainability of the code.

However, Java provides the concept of interfaces, which can achieve similar functionality to multiple inheritance. Interfaces are a type of agreement that defines a set of method specifications without implementation.

A class can implement multiple interfaces to gain the functionality of each. By implementing different interfaces, a class can have different behaviors and achieve different functionalities.

For example, let’s say there are two interfaces, A and B:

public interface A {
    public void methodA();
}

public interface B {
    public void methodB();
}

A class can implement both of these interfaces.

public class MyClass implements A, B {
    public void methodA() {
        // 实现A接口的方法
    }

    public void methodB() {
        // 实现B接口的方法
    }
}

By implementing the interface, the MyClass class can utilize the methods defined in interfaces A and B.

It is important to note that interfaces only define the specifications of methods, not their implementations. Classes that implement interfaces must implement the methods according to the interface specifications themselves. This can avoid conflicts and complexity that come with multiple inheritance.