1、局部内部类

比如：

 2、匿名内部类

package com.lwx.inner;

public class AnonymousInnerClass {
    public static void main(String[] args) {
        Outer02 outer02 = new Outer02();
        outer02.m1();

    }
}

class Outer02{
    private int n1 = 20;
    void m1(){
        System.out.println("Outer02 m1()...");

        IA tiger= new IA(){
            @Override
            public void cry() {
                System.out.println("老虎嗷嗷叫...");
            }
        };

        IA dog = new IA() {
            @Override
            public void cry() {
                System.out.println("小狗汪汪叫...");
            }
        };

        tiger.cry();
        dog.cry();

        Animal cat = new Animal() {
            @Override
            void eat() {
                System.out.println("小猫吃鱼。。。");
            }
        };
        cat.eat();

    }

}

interface IA{
    public void cry();
}


abstract class Animal{
    abstract void eat();
}

3、成员内部类

package com.lwx.inner;

/**
 * @author: lwx
 * @date: 2023-03-09
 */
public class MemberInner {
    public static void main(String[] args) {
        Outer03 outer03 = new Outer03();
        Outer03.Inner03 inner03 = outer03.getInner03();
        inner03.say();
        outer03.t1();

    }

}

class Outer03{
    private  int n1 = 10;
    public String name = "张三";
    private void hi(){
        System.out.println("hi()方法");
    }

    public class Inner03{
        private int n1 = 100;
        private int sal = 200;
        public  void say(){
            System.out.println("n1="+n1+" name="+name+" 外部类的n1"+Outer03.this.n1);
            hi();
        }
    }
    public Inner03 getInner03(){
        return new Inner03();
    }

    public void t1(){
        Inner03 inner03 = new Inner03();
        inner03.say();
        System.out.println(inner03.sal);
    }


}

4、静态内部类的使用

package com.lwx.inner;

/**
 * @author: lwx
 * @date: 2023-03-09 15:53
 */
public class StaticInner {
    public static void main(String[] args) {
        Outer04.inner04 inner04 = new Outer04.inner04();
        inner04.say();
        System.out.println("===========");
        Outer04 outer04 = new Outer04();
        Outer04.inner04 inner041 = outer04.getInner04();
        inner041.say();

    }

}

class Outer04{
    private int n1 = 10;
    public static String name = "张三";
    private static void cry(){
        System.out.println("cry()方法...");
    }

    static class inner04{
        private static String name = "我是静态内部类";
        public void say(){
            System.out.println("name="+name+" 外部类的name="+Outer04.name);
            cry();
            Outer04 outer04 = new Outer04();
            System.out.println(outer04.n1);
        }
    }
    public void m1(){
        inner04 inner04 = new inner04();
        inner04.say();
    }
    public inner04 getInner04(){
        return new inner04();
    }


}