今天学了Java的aggregation,自己总结一下就是:aggregation是association里的一个特殊的分类。aggregation里的关系只能是单向的,而association单向和双向均可。举个例子吧:比如有两个类是Student和Address,在特定情境下,每一个student的对象一定包含了一个Address的对象,而每一个address可以只含有街道名称或是门牌号,不一定...
// Java program to illustrate the// concept of Associationimportjava.io.*;// class bankclassBank{privateString name;// bank nameBank(String name){this.name=name;}publicStringgetBankName(){returnthis.name;}}// employee classclassEmployee{privateString name;// employee nameEmployee(String name)...
Association Association is relation between two separate classes which establishes through their Objects. Association can be one-to-one, one-to-many, many-to-one, many-to-many. In Object-Oriented programming, an Object communicates to other Object to use functionality and services provided by that...
1. Association Association is the most lenient relationship. The association refers to relationships whoseparticipant objects have independent lifecycles and there is no ownership between the objects. Let’s take an example of aTeacherandStudent. A single student can be associated with multiple teacher...
Aggregationin Javais a relationship between two classes that is best described as a "has-a" and "whole/part" relationship. It is a more specialized version of theassociation relationship. The aggregate class contains a reference to another class and is said to have ownership of that class. Ea...
UML的6中关系类图模型以及Java代码实现——EA建模 在UML中共有6种关系: 依赖(Dependency) 继承(泛化)(Generalization) 实现(Realization) 组合(Composition) 聚合(Aggregation) 关联(Association) 强弱关系:泛化(继承) = 实现 > 组合 > 聚合 > 关联 > 依赖 UML6种关系的模型与实现: 1.泛化(继承)关系 (1)泛化...
Example:A Student and a Faculty are having an association. Aggregation Aggregation is a special case of association. A directional association between objects. When an object ‘has-a’ another object, then you have got an aggregation between them. Direction between them specified which object contai...
Association is the representation of the solid line with arrows, there are two key, navigability and multiplicity, navigability is the arrow, refers to the other class, said shall be responsible for the maintenance of association relationship, in this class of data member is refers to the class...
Java 内存模型的组成和各部分的作用 1、先了解一下堆(heap)和栈(stack) 堆和栈都是存在于内存中的两块不同区域,他们都是用于存放数据,不同之处只是在于特性不一样。 1)栈 存取速度比堆要快,仅次于直接位于CPU中的寄存器。但缺点是,存在栈中的数据大小与生存期必须是确定的,缺乏灵活性。另外,栈数据可以...
聚合(aggregation)是一种特殊的关联(association),组合(composition)是一种特殊的聚合。 关联是平级的,无整体与部分的关系,如朋友关系。 聚合... Matrixin 0 911 <123>