c?/span>?/span>c?/span>?/span>?/span>的关p?/span>?/span>于理解面?/span>?/span>象具有很重要的作用，以前在面?/span>?/span>?/span>候也l?/span>常被?/span>?/span>q?/span>?/span>问题Q在q?/span>里我׃l?/span>一下?/span>
c?/span>?/span>c?/span>?/span>?/span>存在以下关系:
(1)泛化(Generalization)
(2)?/span>?/span>(Association)
(3)?/span>?/span>(Dependency)
(4)聚合(Aggregation)
UML?/span>?/span>?/span>用代?/span>例子:
1.泛化(Generalization)
[泛化]
表示c?/span>?/span>c?/span>?/span>?/span>?/span>l?/span>承关p，接口与接口之?/span>?/span>l?/span>承关p，?/span>cd接口?/span>实现关系?/span>一般化的关pL从子c?/span>指向?/span>c?/span>的，?/span>l?/span>承或实现的方法相反?/span>
[具体?/span>?/span>]
?/span>c?/span>?/span>cd例＝new ?/span>c?/span>()
[UML?/span>](?/span>1.1)
?/span>1.1 Animalc?/span>?/span>Tigerc?/span>,Dogc?/span>的泛化关p?/span>
[?/span>?/span>?/span>?/span>]
class Animal{}
class Tiger extends Animal{}
public class Test
{
public void test()
{
Animal a=new Tiger();
}
}
2.?/span>?/span>(Dependency)
[?/span>?/span>]
?/span>于两个相?/span>独立?/span>?/span>象，当一?/span>?/span>?/span>负责构造另一?/span>?/span>象的?/span>例，或者依?/span>另一?/span>?/span>象的?/span>务时Q?/span>q?/span>两个?/span>象之?/span>主要?/span>Cؓ?/span>?/span>关系?/span>
[具体?/span>?/span>]
?/span>?/span>关系?/span>?/span>在局?/span>?/span>量，Ҏ的参敎ͼ以及?/span>?/span>?/span>Ҏ?/span>?/span>?/span>
[现实例子]
比如?/span>你要?/span>?/span>?/span>?/span>Q你是不是要借助(也就是依?/span>)?/span>?/span>刀(Screwdriver)来帮助你完成?/span>?/span>?/span>(screw)的工?/span>
[UML?/span>?/span>](?/span>1.2)
?/span>1.2 Personc?/span>?/span>Screwdriverc?/span>的依?/span>关系
[?/span>?/span>?/span>?/span>]
public class Person{
/** ?/span>?/span>?/span> */
public void screw(Screwdriver screwdriver){
screwdriver.screw();
}
}
3.?/span>?/span>(Association)
[?/span>?/span>]
?/span>于两个相?/span>独立?/span>?/span>象，当一?/span>?/span>象的?/span>例与另一?/span>?/span>象的一些特?/span>?/span>例存在固定的对应关系?/span>Q?/span>q?/span>两个?/span>象之间ؓ?/span>?/span>关系?/span>
[具体?/span>?/span>]
?/span>?/span>关系是?/span>?/span>?/span>?/span>量来实现
[现实例子]
比如?/span>?/span>?/span>订单Q每?/span>订单对应特定的客?/span>Q每个客户对?/span>一些特定的订单Q再例如公司?/span>?/span>工，每个公司对应一些特定的?/span>工，每个?/span>?/span>对应一特定的公?/span>
[UML?/span>] (?/span>1.3)
?/span>1.3 公司?/span>?/span>工的?/span>?/span>关系
[?/span>?/span>?/span>?/span>]
public class Company{
private Employee employee;
public Employee getEmployee(){
return employee;
}
public void setEmployee(Employee employee){
this.employee=employee;
}
//公司q作
public void run(){
employee.startWorking();
}
}
(4)聚合Q?/span>AggregationQ?/span>
[聚合]
?/span>?/span>?/span>A被加入到?/span>?/span>B中，?/span>为对?/span>B?/span>l?/span>成部?/span>?/span>Q?/span>?/span>?/span>B?/span>?/span>?/span>A?/span>间ؓ聚集关系?/span>聚合是关?/span>关系的一U，?/span>较强的关?/span>关系Q?/span>的是整体与部分之?/span>的关pR?/span>
[具体?/span>?/span>]
与关?/span>关系一?/span>Q聚合关pM是?/span>q实?/span>?/span>量来实现q样关系的。关?/span>关系和聚合关pL?/span>法上是没?/span>法区分的Q从语义上才能更好的区分两者的?/span>?/span>?/span>
[?/span>?/span>与聚合的?/span>?/span>]
(1)?/span>?/span>关系所涉及的两?/span>?/span>象是?/span>在同一?/span>?/span>ơ上的。比如h和自?/span>?/span>是一U关?/span>关系Q而不是聚合关p，?/span>?/span>Z是由自行车组成的?/span>
聚合关系涉及的两?/span>?/span>?/span>?/span>于不q等?/span>?/span>ơ上Q一个代表整体，一个代表部分。比?/span>电脑和它?/span>?/span>C器?/span>键盘、主板以及内存就是聚集关p，?/span>?/span>L?/span>电脑?/span>l?/span>成部分?/span>
(2)?/span>于具有聚集关p（其?/span>?/span>聚集关系Q的两个?/span>象，整体?/span>象会?/span>U?/span>它的l?/span>?/span>?/span>象的生命周期。部?/span>c?/span>?/span>?/span>象不?/span>?/span>独存在，它的生命周期?/span>?/span>于整?/span>c?/span>?/span>?/span>象的生命周期Q当整体消失Q部分也随之消失。比?/span>?/span>三的电脑?/span>?/span>了，那么电脑的所?/span>l?/span>件也不存在了Q除?/span>?/span>三事先把一?/span>电脑?/span>l?/span>Ӟ比如?/span>?/span>和内存）拆了下来?/span>
[UML?/span>](?/span>1.4)
?/span>1.3 电脑?/span>l?/span>件的聚合关系
[?/span>?/span>?/span>?/span>]
public class Computer{
private CPU cpu;
public CPU getCPU(){
return cpu;
}
public void setCPU(CPU cpu){
this.cpu=cpu;
}
//开?/span>电脑
public void start(){
//cpuq作
cpu.run();
}
}
////////////////////////////////////////////
我想?/span>?/span>?/span>(Dependency)和关?/span>(Association)做一?/span>?/span>充。不正之?/span>?/span>?/span>指出?/span>
[?/span>?/span>]
?/span>于两个相?/span>独立?/span>?/span>象，当一?/span>?/span>?/span>负责构造另一?/span>?/span>象的?/span>例，或者依?/span>另一?/span>?/span>象的?/span>务时Q?/span>q?/span>两个?/span>象之?/span>主要?/span>Cؓ?/span>?/span>关系?/span>
[具体?/span>?/span>]
?/span>?/span>关系?/span>?/span>在局?/span>?/span>量，Ҏ的参敎ͼ以及?/span>?/span>?/span>?/span>法的?/span>?/span> //除了q?/span>三种外我?/span>q应?/span>包括一?/span>?/span>?/span>?/span>量来实现Q就像关?/span>关系和聚合关pM?/span>法上?/span>?/span>区分一?/span>。依?/span>和关?/span>在某些方面也?/span>?/span>?/span>?/span>法上d分?/span>
[现实例子]
比如?/span>你要?/span>?/span>?/span>?/span>Q你是不是要借助(也就是依?/span>)?/span>?/span>刀(Screwdriver)来帮助你完成?/span>?/span>?/span>(screw)的工?/span>
[?/span>?/span>?/span>?/span>]
java ?/span>?/span>
public class Person {
private ScrewService screwService;
public ScrewService getScrewService() {
return screwService;
}
public void setScrewService(ScrewService screwService) {
this.screwService = screwService;
}
public void screw(){
screwService.screw();
}
}
我不知道假如是以上代?/span>情况seagar x?/span>们归入那U关?/span>。以我的x是?/span>?/span>仍然属于?/span>?/span>关系Q因为现在我是?/span>spring来把ScrewServiceImpl注入 screwService的。而且它也W合当一?/span>?/span>?/span>负责构造另一?/span>?/span>象的?/span>例，或者依?/span>另一?/span>?/span>象的?/span>?/span>?/span>q?/span>个定?/span>。所以我想以上情冉|?/span>归ؓ?/span>?/span>关系会比?/span>合适一炏V?/span>
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