内部类，静态内部类（不常用）

package com.javatest20170224.InnerClass;

//定义一个外部类
class Outter{
    String name = "outtername";
    public void test(){
        System.out.println(this.new Inner().age);
    }
    //定义一个内部类
    class Inner {
        String name = "Innername";
        int age= 17;
        void inner(){
            String name = "localname";
            
            System.out.println("inner 方法");
            
            System.out.println(name);
            System.out.println(this.name);
            System.out.println(Outter.this.name);//内部类方法调用外部成员变量。
        }
    }
}
public class InerClassDemo {
    public static void main(String[] args) {
        Outter outter = new Outter();
        System.out.println(outter);//com.javatest20170224.InnerClass.Outter@15db9742
        Outter.Inner  in = outter.new Inner();
        System.out.println(in);//com.javatest20170224.InnerClass.Outter$Inner@15db9742
        
        in.inner();//inner 方法
        outter.test();//17
        
    }
}

静态内部类使用

package com.javatest20170224.InnerClass;
class Outter2{
    String name ="outterName";
    static String name2 = "outtername2";
            public void test(){
        System.out.println("Outtertest");
    }
    static class Inner{
        String name = "InnnerName";
        static int age =19;
        void innerTest(){
            String name = "InnerTestname";
            System.out.println(name);
            System.out.println(this.name);
            //静态内部类可以直接访问外部静态成员。
            System.out.println(name2);
            //静态内部类通过外部类对象访问外部非静态成员。
            System.out.println(new Outter2().name);
            new Outter2().test();
        }
    }
}
public class StaticInnerClass {
    public static void main(String[] args) {
        Outter2 outter2 = new Outter2();
        Outter2.Inner in =new Outter2.Inner();
        in.innerTest();
        //测试类可以直接通过完整的类名调用静态内部类的静态成员，
        System.out.println(Outter2.Inner.age);//19
    }
}