UML之十字圆圈连线箭头符号“包含”C…

　　在UML的类图里，这个一头带个十字圆圈（注意，不是带叉的圆圈）与连线组成的形式，表示内嵌。在实际编程代码中表示嵌在内部的类，通常用来表示突然在内部需要一个匿名类（如new Thread()或者new Runnable()的情况）。

　　英文介绍如下（摘自 http://www.holub.com/goodies/uml/）： Nesting, Inner Class.. Identifies nesting (containment) relationships in all diagrams. In a class diagram: an "inner" class whose definition is nested within the "outer" class definition. Typically puts the inner class in the name space of the outer class, but may have additional properties.

　　下面举个例子：

本图所对应的Java代码为：

public class SimpleClass {         private Integer num = 3;         private Boolean isGood;         public Boolean isGoodEnough(Integer goodrange) {             return null;         }         public Integer getNum() {             return null;         }         public class InnerClass {             private Integer coolNum;             public Integer getCoolNum() {                 return null;             }         }     }

对应的C++代码：

#ifndef SIMPLECLASS_H_H #define SIMPLECLASS_H_H class SimpleClass{ public:              class InnerClass{              public:                           Integer getCoolNum( );              private:                           Integer coolNum;              };              Integer getNum( );              Boolean isGoodEnough( Integer goodrange ); private:              Boolean isGood;              Integer num; }; #endif

#include "SimpleClass.h" Integer SimpleClass::InnerClass::getCoolNum( ){ } Boolean SimpleClass::isGoodEnough( Integer goodrange ){ } Integer SimpleClass::getNum( ){ }