No enclosing instance of type XXX is accessible.

一个类LambdaChapter3 中有另一个类Artist (外部类和内部类), 如果使用new 的方式创建内部类的对象,会报错:No enclosing instance of type LambdaChapter3 is accessible.
报错信息:

No enclosing instance of type LambdaChapter3 is accessible. Must qualify the allocation with an enclosing instance of type LambdaChapter3 (e.g. x.new A() where x is an instance of LambdaChapter3 ).

原因:
内部类是动态的（无static关键字修饰），而main方法是静态的，普通的内部类对象隐含地保存了一个引用，指向创建它的外围类对象，所以要在static方法（类加载时已经初始化）调用内部类的必须先创建外部类。

解决方法:
创建内部类对象应该:
方法1:外部类对象.内部类对象 (保证外部类对象先于内部类对象出现)

DanymicTest test = new StaticCallDynamic().new DanymicTest();

其中StaticCallDynamic为外部类，DanymicTest为内部动态类；
方法2:
如果将内部类修改为静态类，可以在main中直接创建内部类实例。

//外部类LambdaChapter3 
public class LambdaChapter3 {

    public static void main(String[] args) {
        ArrayList allArtists  = new ArrayList();
        //Artist artist = new LambdaChapter3().new Artist("zhangsan", "London");
        Artist artist = new Artist("zhangsan", "London");
        allArtists.add(artist);
        artistNationnal_java8(allArtists);
    }

    //内部类 Artist
    class  Artist {
        private String name;
        private String city;


        public Artist(String name, String city) {
            super();
            this.name = name;
            this.city = city;
        }


        public String getName() {
            return name;
        }


        public void setName(String name) {
            this.name = name;
        }


        public String getCity() {
            return city;
        }


        public void setCity(String city) {
            this.city = city;
        }


        public boolean isFrom(String string) {
            return string.equals("London");
        }


        public void setIsFrom(String isFrom) {
            this.city = isFrom;
        }

    }

}