枚举

• 构建1个maven项目，导入依赖

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <version>2.6.1</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-webflux</artifactId>
        <version>2.6.1</version>
    </dependency>
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
        <version>3.4.0</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.27</version>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.18</version>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.assertj</groupId>
        <artifactId>assertj-core</artifactId>
        <version>3.21.0</version>
        <scope>compile</scope>
    </dependency>
</dependencies>

• 编写yml，重点是扫描枚举类的路径

server:
  port: 8080

spring:
  application:
    name: demo01
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=UTF-8
    username: root
    password: 123456
  main:
    allow-circular-references: true
  devtools:
    restart:
      enabled: true

mybatis:
  configuration:
    map-underscore-to-camel-case: true
mybatis-plus:
  type-enums-package: org.example.demo01.enums
  configuration:
    # 3.0.8之前版本问题默认将枚举注册为EnumOrdinalTypeHandler,这是错误的方式,默认是 org.apache.ibatis.type.EnumTypeHandler
    # 如果项目之中实体统一使用IEnum或注解的方式,可配置成 com.baomidou.mybatisplus.extension.handlers.EnumTypeHandler,也可省略上面的type-enums-package配置
    # 配置type-enums-package只对注解方式的枚举处理能提前加载缓存.
    default-enum-type-handler: org.apache.ibatis.type.EnumOrdinalTypeHandler
logging:
  level:
    org:
      example:
        demo01: debug

• 配置类

@Configuration
@MapperScan("org.example.demo01.mapper")
public class MybatisPlusConfig {

}

• 编写枚举类方式1：枚举实现IEnum接口

public enum AgeEnum implements IEnum<Integer> {
  ONE(1, "一岁"),
  TWO(2, "二岁"),
  THREE(3, "三岁");

  private int value;
  private String desc;

  AgeEnum(final int value, final String desc) {
    this.value = value;
    this.desc = desc;
  }

  @Override
  public Integer getValue() {
    return value;
  }
}

• 编写枚举类方式2：使用@EnumValue注解

@Getter
public enum GradeEnum {

    PRIMARY(1, "小学"),
    SECONDORY(2, "中学"),
    HIGH(3, "高中");

    GradeEnum(int code, String descp) {
        this.code = code;
        this.descp = descp;
    }

    @EnumValue
    private final int code;
    private final String descp;

}

• 序列化枚举值为数据库存储值 -> 参考官网

# 如下方式为注解处理
public enum GradeEnum {

    PRIMARY(1, "小学"),  SECONDORY(2, "中学"),  HIGH(3, "高中");

    GradeEnum(int code, String descp) {
        this.code = code;
        this.descp = descp;
    }

    @EnumValue
    @JsonValue	//标记响应json值
    private final int code;
}