# DevelopersGuide

**Repository Path**: Clara77/developers-guide

## Basic Information

- **Project Name**: DevelopersGuide
- **Description**: alibaba
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2021-11-29
- **Last Updated**: 2021-11-29

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# 开发手册

## OOP风格

### float

> ​		浮点数之间的等值判断，基本数据类型不能用 == 比较，包装数据类型不能用equals来判断

​	![image-20210811224756895](assets/image-20210811224756895.png)

![image-20210811224818364](assets/image-20210811224818364.png)

#### BigDecimal 

> ​	BigDecimal 的等值比较应该使用compareTo()方法，而不是equals()方法
>
> ​		Note：equals()方法会比较值的精度(1.0 与 1.00 返回结果为fasle)
>
> ​		compareTo 会忽略精度
>
> Note：禁止使用构造方法(double) 的方式把double值转化为BigDecimal对象的
>
> ![image-20210811225826717](assets/image-20210811225826717.png)
>
> 

## 日期规范

​	1.

![image-20210811230717228](assets/image-20210811230717228.png)

2.

![image-20210811230820958](assets/image-20210811230820958.png)

3.

![image-20210811231027804](assets/image-20210811231027804.png)



## 集合处理

​	1.

![image-20210811231359914](assets/image-20210811231359914.png)

> Note：必须重写equals 和 hashcode方法 ！，如果需要使用自定义对象作为map中的key的话

2.

> ​	使用isEmpty() 去判断集合是否为空 而不是 size() == 0

3.

![image-20210811232132957](assets/image-20210811232132957.png)

4.

![image-20210811232621354](assets/image-20210811232621354.png)

5.

![())](assets/image-20210811233709176.png)

6.(※)

![image-20210811234538261](assets/image-20210811234538261.png)

7.

![image-20210811234940000](assets/image-20210811234940000.png)

8.

![image-20210811235710654](assets/image-20210811235710654.png)

9.

![image-20210811235816734](assets/image-20210811235816734.png)

10.

![image-20210812000430236](assets/image-20210812000430236.png)

## 并发控制

​	1.

![image-20210812154606660](assets/image-20210812154606660.png)

2.

![image-20210812154647300](assets/image-20210812154647300.png)

3.

![image-20210812155421230](assets/image-20210812155421230.png)

4.

![image-20210812155535583](assets/image-20210812155535583.png)

5.

![image-20210812155710759](assets/image-20210812155710759.png)

6.

![image-20210812155908938](assets/image-20210812155908938.png)

7.

![image-20210812161428795](assets/image-20210812161428795.png)

8.

![image-20210812162232680](assets/image-20210812162232680.png)

8 - code:

![image-20210812161837113](assets/image-20210812161837113.png)

9.

![image-20210812164317209](assets/image-20210812164317209.png)

10.

![image-20210812164739938](assets/image-20210812164739938.png)

## 前后规约

1.

![image-20210812165145792](assets/image-20210812165145792.png)

2.

![image-20210812165315335](assets/image-20210812165315335.png)

3.

![image-20210812165436756](assets/image-20210812165436756.png)

4.

![image-20210812165624925](assets/image-20210812165624925.png)

## 其他

1.

![image-20210812170449634](assets/image-20210812170449634.png)

2.

![image-20210812170538740](assets/image-20210812170538740.png)

3.

![image-20210812170635293](assets/image-20210812170635293.png)

## 异常日志

1.

![image-20210812170753557](assets/image-20210812170753557.png)

2.

![image-20210812170925680](assets/image-20210812170925680.png)

## 异常处理

1.

![image-20210812171513824](assets/image-20210812171513824.png)

2.

![image-20210812171536701](assets/image-20210812171536701.png)

3.

![image-20210812172515742](assets/image-20210812172515742.png)

## 日志规约

1.

![image-20210812173128019](assets/image-20210812173128019.png)2.

![image-20210812173326776](assets/image-20210812173326776.png)

3.

![image-20210812173539133](assets/image-20210812173539133.png)

4.

![image-20210812173701087](assets/image-20210812173701087.png)

5.

![image-20210812173948589](assets/image-20210812173948589.png)

## 安全规约

![image-20210812175702304](assets/image-20210812175702304.png)

## 数据库规约

1.

![image-20210812181046660](assets/image-20210812181046660.png)

2.

![image-20210812181545037](assets/image-20210812181545037.png)

3.

![image-20210812181659580](assets/image-20210812181659580.png)

4.

![image-20210812181810827](assets/image-20210812181810827.png)

5.

![image-20210812181930863](assets/image-20210812181930863.png)

## sql语句

1.

![image-20210812182047131](assets/image-20210812182047131.png)

2.



# 小点

> 1. 并发
>
>    ![image-20210812154447822](assets/image-20210812154447822.png)
>
> 2. 并发
>
>    ![image-20210812155749252](assets/image-20210812155749252.png)

​