最佳实践

1.SpringBoot 应用如何编写

• 引入场景依赖
  • 官方文档
• 查看自动配置了哪些（选做）
  • 自己分析，引入场景对应的自动配置一般都生效了
  • 配置文件中 debug=true 开启自动配置报告。
    • Negative（不生效）
    • Positive（生效）
• 是否需要修改
  • 参照文档修改配置项
    • 官方文档
    • 自己分析。xxxxProperties 绑定了配置文件的哪些。
  • 自定义加入或者替换组件
    • @Bean、@Component…
  • 自定义器 XXXXXCustomizer；

2.Lombok 简化开发

Lombok 用标签方式代替构造器、getter/setter、toString()等鸡肋代码。

spring boot 已经管理 Lombok。引入依赖：

<dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId>
</dependency>

IDEA 中 File->Settings->Plugins，搜索安装 Lombok 插件。

java">@NoArgsConstructor
//@AllArgsConstructor
@Data
@ToString
@EqualsAndHashCode
public class User {private String name;private Integer age;private Pet pet;public User(String name,Integer age){this.name = name;this.age = age;}
}

简化日志开发

java">@Slf4j
@RestController
public class HelloController {@RequestMapping("/hello")public String handle01(@RequestParam("name") String name){log.info("请求进来了....");return "Hello, Spring Boot 2!"+"你好："+name;}
}

3.dev-tools

Spring Boot includes an additional set of tools that can make the application development experience a little more pleasant. The spring-boot-devtools module can be included in any project to provide additional development-time features.——link

Applications that use spring-boot-devtools automatically restart whenever files on the classpath change. This can be a useful feature when working in an IDE, as it gives a very fast feedback loop for code changes. By default, any entry on the classpath that points to a directory is monitored for changes. Note that certain resources, such as static assets and view templates, do not need to restart the application.——link

Triggering a restart

As DevTools monitors classpath resources, the only way to trigger a restart is to update the classpath. The way in which you cause the classpath to be updated depends on the IDE that you are using:

• In Eclipse, saving a modified file causes the classpath to be updated and triggers a restart.
• In IntelliJ IDEA, building the project (Build -> Build Project)(shortcut: Ctrl+F9) has the same effect.

添加依赖：

<dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId><optional>true</optional></dependency>
</dependencies>

在 IDEA 中，项目或者页面修改以后：Ctrl+F9。

4.Spring Initailizr

Spring Initailizr是创建 Spring Boot 工程向导。

在 IDEA 中，菜单栏 New -> Project -> Spring Initailizr。

配置文件

yarm 的用法

同以前的 properties 用法

YAML 是 “YAML Ain’t Markup Language”（YAML 不是一种标记语言）的递归缩写。在开发的这种语言时，YAML 的意思其实是：“Yet Another Markup Language”（仍是一种标记语言）。

非常适合用来做以数据为中心的配置文件。

1.基本语法

• key: value；kv 之间有空格
• 大小写敏感
• 使用缩进表示层级关系
• 缩进不允许使用 tab，只允许空格
• 缩进的空格数不重要，只要相同层级的元素左对齐即可
• '#'表示注释
• 字符串无需加引号，如果要加，单引号’'、双引号""表示字符串内容会被 转义、不转义

2.数据类型

• 字面量：单个的、不可再分的值。date、boolean、string、number、null

k: v

• 对象：键值对的集合。map、hash、set、object

#行内写法：k: {k1:v1,k2:v2,k3:v3}#或k:k1: v1k2: v2k3: v3

• 数组：一组按次序排列的值。array、list、queue

#行内写法：k: [v1,v2,v3]#或者k:- v1- v2- v3

3.实例

java">@Data
public class Person {private String userName;private Boolean boss;private Date birth;private Integer age;private Pet pet;private String[] interests;private List<String> animal;private Map<String, Object> score;private Set<Double> salarys;private Map<String, List<Pet>> allPets;
}@Data
public class Pet {private String name;private Double weight;
}

用 yaml 表示以上对象

person:userName: zhangsanboss: falsebirth: 2019/12/12 20:12:33age: 18pet:name: tomcatweight: 23.4interests: [篮球, 游泳]animal:- jerry- marioscore:english:first: 30second: 40third: 50math: [131, 140, 148]chinese: { first: 128, second: 136 }salarys: [3999, 4999.98, 5999.99]allPets:sick:- { name: tom }- { name: jerry, weight: 47 }health: [{ name: mario, weight: 47 }]

自定义类绑定的配置提示

You can easily generate your own configuration metadata file from items annotated with @ConfigurationProperties by using the spring-boot-configuration-processor jar. The jar includes a Java annotation processor which is invoked as your project is compiled.——link

自定义的类和配置文件绑定一般没有提示。若要提示，添加如下依赖：

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-configuration-processor</artifactId><optional>true</optional>
</dependency><!-- 下面插件作用是工程打包时，不将spring-boot-configuration-processor打进包内，让其只在编码的时候有用 -->
<build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId><configuration><excludes><exclude><groupId>org.springframework.boot</groupId><artifactId>spring-boot-configuration-processor</artifactId></exclude></excludes></configuration></plugin></plugins>
</build>

模板

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><!--项目maven坐标--><groupId>com.nianxi</groupId><artifactId>springboot-mybatis-demo</artifactId><version>1.0-SNAPSHOT</version><!--    继承spring-boot-starter-parent--><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>3.1.2</version></parent><!--属性设置--><properties><maven.compiler.source>17</maven.compiler.source><maven.compiler.target>17</maven.compiler.target><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><mysql.version>8.0.33</mysql.version><mybatis-plus.version>3.5.3.1</mybatis-plus.version><lombok.version>1.18.24</lombok.version><devtools.version>3.2.4</devtools.version></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId></dependency><!--devtools--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId><version>${devtools.version}</version></dependency><!-- mysql --><dependency><groupId>com.mysql</groupId><artifactId>mysql-connector-j</artifactId><version>${mysql.version}</version></dependency><!-- mybatis-plus --><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>${mybatis-plus.version}</version></dependency><!-- lombok --><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>${lombok.version}</version></dependency><!--字符串的处理--><dependency><groupId>org.apache.commons</groupId><artifactId>commons-lang3</artifactId></dependency></dependencies><!--添加maven插件，项目的打包工具，打成jar包，否则在打包运行时报错   --><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build>
</project>

application.yml

server:port: 8080spring:profiles:# 设置当前环境,用来区分不同环境的配置active: devmain:# 设置banner模式,用来关闭启动时的图标allow-circular-references: true# 配置Spring boot数据源datasource:driver-class-name: ${star.datasource.driver-class-name}url: ${star.datasource.url}username: ${star.datasource.username}password: ${star.datasource.password}# 配置mybatis-plus
mybatis-plus:configuration:# 配置驼峰命名(实体类属性与数据库字段名称的下划线规则)map-underscore-to-camel-case: true# 日志log-impl: org.apache.ibatis.logging.stdout.StdOutImpl# 实体类别名type-aliases-package: com.nianxi.entity# 全局配置global-config:db-config:# 主键类型id-type: auto# 映射文件位置mapper-locations: classpath:mapper/*Mapper.xml# 日志配置
logging:level: # 日志级别com:nianxi:mapper: debug # mapper包下的日志级别为debugservice: infocontroller: info

application-dev.yml

star:datasource:driver-class-name: com.mysql.cj.jdbc.Driverurl: jdbc:mysql://localhost:3306/springbootDemo?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=Asia/Shanghaiusername: rootpassword: 123456

java_397">common.Result.java

java">package com.nianxi.common;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;@Data
@AllArgsConstructor
@NoArgsConstructor
public class Result<T> {// 状态码 0为成功，1为失败private Integer code;// 返回信息private String msg;// 返回前端的数据private T data;public static <T> Result<T> success() {Result<T> result = new Result<T>();result.code = 1;return result;}public static <T> Result<T> success(T object) {Result<T> result = new Result<T>();result.data = object;result.code = 1;return result;}public static <T> Result<T> error(String msg) {Result<T> result = new Result<T>();result.msg = msg;result.code = 0;return result;}
}

java_439">config.MyBatisPlusConfig.java

java">package com.nianxi.config;import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;@Configuration
public class MyBatisPlusConfig {//分页插件@Beanpublic MybatisPlusInterceptor mybatisPlusInterceptor() {MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();//设置数据库类型mybatisPlusInterceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));return mybatisPlusInterceptor;}//RestTemplate@Beanpublic RestTemplate restTemplate() {return new RestTemplate();}
}