CS-Notes/notes/面向对象思想.md

<!-- GFM-TOC -->
* [S.O.L.I.D](#solid)
    * [1. ??????????](#1-??????????)
    * [2. ?????????](#2-?????????)
    * [3. ?????<3F>I???](#3-?????<3F>I???)
    * [4. ?????????](#4-?????????)
    * [5. ???????????](#5-???????????)
* [???????<3F><>????](#???????<3F><>????)
    * [1. ???](#1-???)
    * [2. ???](#2-???)
    * [3. ???](#3-???)
* [UML](#uml)
    * [1. ???](#1-???)
    * [2. ????](#2-????)
* [?<3F><>?????](#?<3F><>?????)
<!-- GFM-TOC -->

# S.O.L.I.D

S.O.L.I.D???????????????(OOD&OOP)?<3F><>?????????????(Programming Priciple)?????????<3F><>??

|??<3F><>    |??    |???????|
| -- | -- | -- |
|SRP|    The Single Responsibility Principle    |??????????|
|OCP|    The Open Closed Principle            | ?????????|
|LSP|    The Liskov Substitution Principle    |?????<3F>I???|
|ISP|    The Interface Segregation Principle    |?????????|
|DIP|    The Dependency Inversion Principle    |???????????|


## 1. ??????????

???????????????????????????????????<3F><>?????????????????????????<3F><>????????????<3F><>?????????????<3F><>????????????????

## 2. ?????????

?????????????????????????????????????????????????????????????

## 3. ?????<3F>I???

????????????????????<3F>I?<3F><>??????????????????????? is-a ?????

## 4. ?????????

?????????????????<3F><>???????????????<3F><>??????????????????????????????<3F><>?

## 5. ???????????

1.  ?????<3F><>?????????????<3F><>?????????????????
2.  ????????????????????????????????

# ???????<3F><>????

???????<3F><>???????????????????????

## 1. ???

???<3F><>??????????????????????????????????????<3F>q?????????????????<3F><>??????????????????????????????????????????????????????<3F><>????????????????????????????????????????????????????????????????????????????????

?????????????

1. ??????????????????

2. ????????????????????

3. ??????????<3F><>??????????

4. ????????????????

???? Person ???? name??gender??age ???????????????? get() ?????????? Person ????? name ????? gender ????????????? age ????????? age ???????? work() ??????<3F><>?

??? gender ??????? int ??????????<3F>՛<EFBFBD>????????????????????????????????????????????????????????????????????????????????<3F><>?

```java
public class Person {
    private String name;
    private int gender;
    private int age;

    public String getName() {
        return name;
    }

    public String getGender() {
        return gender == 0 ? "man" : "woman";
    }

    public void work() {
        if(18 <= age && age <= 50) {
            System.out.println(name + " is working very hard!");
        } else {
            System.out.println(name + " can't work!");
        }
    }
}
```

## 2. ???

???????? **is-a** ????????? Cat ?? Animal ??????? is-a ???????????? Cat ????? Animal???????? Animal ?? private ????????????

Cat ??????? Animal ????????????????? Animal ???? Cat ?????????????????????? **???????**??

??????????????<3F>I??????????????????????<3F>I?<3F><>??????????????????????? is-a ?????

```java
Animal animal = new Cat();
```

## 3. ???

???????????????????????????????????????????????????????????????<3F><>???????????????????????????????????????

???????????????1. ??<3F><>?2. ???????????3. ????????

?????????<3F><>???????Instrument????????????Wind ?? Percussion????????????? play() ???????????? main() ???????????? Instrument ?????? Wind ?? Percussion ?????? Instrument ??????? play() ????????????????????????????? play() ???????????? Instrument ????????

```java
public class Instrument {
    public void play() {
        System.out.println("Instument is playing...");
    }
}

public class Wind extends Instrument {
    public void play() {
        System.out.println("Wind is playing...");
    }
}

public class Percussion extends Instrument {
    public void play() {
        System.out.println("Percussion is playing...");
    }
}

public class Music {
    public static void main(String[] args){
        List<Instrument> instruments = new ArrayList<>();
        instruments.add(new Wind());
        instruments.add(new Percussion());
        for(Instrument instrument : instruments){
            instrument.play();
        }
    }
}

```



# UML

## 1. ???

**1.1 ??????**

????????????: ??????generalize????????realize????????? is-a ?????

?? ???????(generalization)

????????<3F><>??

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/29badd92-109f-4f29-abb9-9857f5973928.png)

?? ?????(realize)

?????????????<3F><>??

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/4b16e1d3-3a60-472c-9756-2f31b1c48abe.png)

**1.2 ????????**

?? ?????(aggregation)

??????????????????????????????????????????<3F>I????????????????????<3F><>?? B ?? A ????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/34259bb8-ca3a-4872-8771-9e946782d9c3.png)


?? ?????(composition)

??????????????????????????????????<3F>I??????????????????????<3F>M??????????????????????????????????????????????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/7dda050d-ac35-4f47-9f51-18f18ed6fa9a.png)

**1.3 ?????**

?? ???????(association)

???????????????<3F><>????????????????????????<3F><>??????????????????????????????????? 1 ?? 1????? 1?????????????????????????????????<3F><>???????????????????<3F><>?????<3F><>??????????????????????????<3F><>??????????????????????????<3F><>??????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/4ccd294c-d6b2-421b-839e-d88336ff5fb7.png)

?? ???????(dependency)

???????????????, ??????????????<3F><>??????????????????????????????????????????????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/47ca2614-509f-476e-98fc-50ec9f9d43c0.png)


## 2. ????

**2.1 ????**

??????????????????????????????????????????????????????????????????????????????????????????????????????????????

**2.2 ?????????**

????????????<3F><>???????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/80c5aff8-fc46-4810-aeaa-215b5c60a003.png)

????????????????????????????????????

```java
publc class ???? {
   public void ??();
}

publc class  ???? {
  public void  ??????();
  public void  ???????();
  private void ?ڈ???();
}

public class ???? {
    public void  ?????G??();
}

public class ??? {
   public void  ??????????();
}

public class ??? {
   public void  ???????();
}
```

**2.3 ???????????????**

?????????????????????????

?????????????????????????????????????

**2.4 ?????????????**

????????????????????????????????????

**2.5 ?????????**

?? ????

????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/25b8adad-2ef6-4f30-9012-c306b4e49897.png)

????????????????????

1. ?????????????????????

2. ????????????????????????????????????????????????

?? ??????

???????????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/b7b0eac6-e7ea-4fb6-8bfb-95fec6f235e2.png)

?? ???

?????????????????????????????

?????4???????

1\. ????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/a13b62da-0fa8-4224-a615-4cadacc08871.png)

2\. ????????????????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/33821037-dc40-4266-901c-e5b38e618426.png)

3\. ?????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/dec6c6cc-1b5f-44ed-b8fd-464fcf849dac.png)

4\. ??????????????

?? ????

???????????????????????????????????????

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/6ab5de9b-1c1e-4118-b2c3-fb6c7ed7de6f.png)


# ?<3F><>?????

- Java ??????

- [???????????SOLID???](http://www.cnblogs.com/shanyou/archive/2009/09/21/1570716.html)

- [????UML?????????](http://design-patterns.readthedocs.io/zh_CN/latest/read_uml.html#generalization)

- [UML??<3F><>???????????????sequence diagram](http://www.cnblogs.com/wolf-sun/p/UML-Sequence-diagram.html)

- [?????????????????------???????<3F><>????](http://blog.csdn.net/jianyuerensheng/article/details/51602015)