SpringBoot（Lombok + Spring Initailizr + yaml）

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 {
    @Resource
    private 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: 100
  name: 牛魔王
  age: 500
  isMarried: false
  birth: 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: 100
  name: 牛魔王
  age: 500
  isMarried: false
  birth: 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}]}