SpringBoot（Lombok + Spring Initailizr + yaml）-编程知识

1.Lombok

1.基本介绍

2.应用实例

1.pom.xml 引入Lombok，使用版本仲裁

    <!--导入springboot父工程--><parent><artifactId>spring-boot-starter-parent</artifactId><groupId>org.springframework.boot</groupId><version>2.5.3</version></parent><dependencies><!--配置maven项目场景启动器，自动导入和web相关的包--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><!--引入Lombok，使用版本仲裁--><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency></dependencies>

2.@Data注解说明

相当于Getter, Setter, RequiredArgsConstructor, ToString, EqualsAndHashCode,Value这些注解的组合
主要记住Getter, Setter,ToString

package lombok;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
* Generates getters for all fields, a useful toString method, and hashCode and equals implementations that check
* all non-transient fields. Will also generate setters for all non-final fields, as well as a constructor.
*

* Equivalent to {@code @Getter @Setter @RequiredArgsConstructor @ToString @EqualsAndHashCode}.
*

* Complete documentation is found at the project lombok features page for @Data.
*
* @see Getter
* @see Setter
* @see RequiredArgsConstructor
* @see ToString
* @see EqualsAndHashCode
* @see lombok.Value
/
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.SOURCE)
public @interface Data {
/*
* If you specify a static constructor name, then the generated constructor will be private, and
* instead a static factory method is created that other classes can use to create instances.
* We suggest the name: “of”, like so:
*
*
*     public @Data(staticConstructor = “of”) class Point { final int x, y; }

* 
*
* Default: No static constructor, instead the normal constructor is public.
*
* @return Name of static ‘constructor’ method to generate (blank = generate a normal constructor).
*/
String staticConstructor() default “”;
}

3.@RequiredArgsConstructor注解说明（不常用）

4.@NoArgsConstructor无参构造器

5.@AllArgsConstructor全参构造器

注意事项：

当使用全参构造器时，默认的无参构造器会消失
如果还想要无参构造器就需要使用无参构造器的注解

6.两种使用Lombok的方式

1.需要Getter, Setter,ToString,无参构造器

@Data

2.需要使用Getter, Setter,ToString,无参构造器,全参构造器

@Data
@AllArgsConstructor
@NoArgsConstructor

3.在IDEA中安装Lombok插件解锁扩展注解

1.安装插件

2.扩展注解：日志输出

1.代码实例

2.会在日志中输出

2.Spring Initailizr（不推荐）

1.基本介绍

2.通过IDEA方式创建

1.新创建一个项目

2.进行配置

3.创建成功

3.通过官网创建

1.进入官网

2.配置完之后选择

3.最后会生成一个.zip文件，解压之后在IDEA中打开即可

4.第一次使用自动配置爆红

3.yaml

1.基本说明

2.yaml基本语法

3.yaml数据类型

1.字面量

2.对象

3.数组

4.yaml应用实例

1.创建一个新的maven项目

2.pom.xml引入依赖并刷新maven

    <!--导入springboot父工程--><parent><artifactId>spring-boot-starter-parent</artifactId><groupId>org.springframework.boot</groupId><version>2.5.3</version></parent><dependencies><!--配置maven项目场景启动器，自动导入和web相关的包--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><!--引入Lombok，使用版本仲裁--><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency></dependencies>

3.编写两个bean

1.Car.java

package com.sun.springboot.bean;import lombok.Data;
import org.springframework.stereotype.Component;/*** @author 孙显圣* @version 1.0*/
@Data //getter，setter，tostring，无参构造
@Component
public class Car {private String name;private Double price;}

2.Monster.java

package com.sun.springboot.bean;import lombok.Data;
import org.springframework.stereotype.Component;import java.util.*;/*** @author 孙显圣* @version 1.0*/
@Data
@Component
public class Monster {private Integer id;private String name;private Integer age;private Boolean isMarried;private Date birth;private Car car;private String[] skill;private List<String> hobby;private Map<String, Object> wife;private Set<Double> salaries;private Map<String, List<Car>> cars;}

4.HiController.java 接受请求

package com.sun.springboot.controller;import com.sun.springboot.bean.Monster;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import javax.annotation.Resource;/*** @author 孙显圣* @version 1.0*/
@RestController
public class HiController {@Resourceprivate Monster monster;@RequestMapping("/monster")public Monster monster() {return monster;}
}

5.主程序Application.java

package com.sun.springboot;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;/*** @author 孙显圣* @version 1.0*/
@SpringBootApplication
public class Application {public static void main(String[] args) {SpringApplication.run(Application.class);}
}

6.运行主程序（目前返回的值是空的）

7.创建yaml文件（后缀也可以是yml） resources/application.yml

monster: #前缀id: 100name: 牛魔王age: 500isMarried: falsebirth: 2000/11/11

8.绑定数据到Monster类

9.解决报错

1.因为使用@Configuration注解导致的问题

2.在pom.xml中添加依赖即可

    <dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-configuration-processor</artifactId><!--防止将该依赖传递到其他模块--><optional>true</optional></dependency>

3.运行主程序

10.完整yml文件

monster: #前缀id: 100name: 牛魔王age: 500isMarried: falsebirth: 2000/11/11#对象类型
#  car: {name: 宝马, price: 1000} #行内格式car:name: 奔驰price: 3000#数组类型
#  skill: [芭蕉扇, 牛魔拳] #行内格式skill:- 牛魔王- 芭蕉扇#list类型
#  hobby: [白骨精, 美人鱼]hobby:- 白骨精- 牛魔王#map类型
#  wife: {no1: 牛魔王, no2: 猪八戒}wife:no1: 白骨精no2: 铁扇公主#set类型
#  salaries: [1, 2, 3]salaries:- 4- 5- 6#map<String, List<Car>>类型cars:car1: [{name: 奔驰, price: 400},{name: 奔驰, price: 400}]car2: [{name: 奔驰, price: 400},{name: 奔驰, price: 400}]#  cars: {car1: [{name: 奔驰, price: 200}, {name: 奔驰, price: 200}],
#          car2: [{name: 奔驰, price: 200}, {name: 奔驰, price: 200}]}