JAVA——内部类

在Java中写一个内部类必须在前面加上修饰符 static，不然会报错

例如，在JAVA中：

public class Main { private class NEXT{ int x,y,c; }; public static void main(){ NEXT next = new NEXT(); } }会报错： 

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

但是将 private class NEXT 改为 private static class NEXT 就可以了。