SpringBoot与MybatisPlus3.X整合之通用枚举(十二)

一 通用枚举

解决了繁琐的配置，让 mybatis 优雅的使用枚举属性！

自3.1.0开始,可配置默认枚举处理类来省略扫描通用枚举配置 默认枚举配置

• 升级说明:

  3.1.0 以下版本改变了原生默认行为,升级时请将默认枚举设置为EnumOrdinalTypeHandler

• 影响用户:

  实体中使用原生枚举

• 其他说明:

  配置枚举包扫描的时候能提前注册使用注解枚举的缓存

• 推荐配置:

  • 使用实现

    IEnum

    接口

    • 推荐配置defaultEnumTypeHandler

  • 使用注解枚举处理

    • 推荐配置typeEnumsPackage

  • 注解枚举处理与

    IEnum

    接口

    • 推荐配置typeEnumsPackage

  • 与原生枚举混用

    • 需配置defaultEnumTypeHandler与 typeEnumsPackage

申明通用枚举属性

方式一： 使用 @EnumValue 注解枚举属性 完整示例

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//标记数据库存的值是code
    private final int code;
    //。。。
}

方式二： 枚举属性，实现 IEnum 接口如下：

public enum AgeEnum implements IEnum<Integer> {
    ONE(1, "一岁"),
    TWO(2, "二岁"),
    THREE(3, "三岁");
 
    private int value;
    private String desc;
 
    @Override
    public Integer getValue() {
        return this.value;
    }
}

实体属性使用枚举类型

public class User{
    /**
     * 名字
     * 数据库字段: name varchar(20)
     */
    private String name;
 
    /**
     * 年龄，IEnum接口的枚举处理
     * 数据库字段：age INT(3)
     */
    private AgeEnum age;
 
    /**
     * 年级，原生枚举（带{@link com.baomidou.mybatisplus.annotation.EnumValue}):
     * 数据库字段：grade INT(2)
     */
    private GradeEnum grade;
}

二 代码

• pom.xml

  <dependencies>
          <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter</artifactId>
          </dependency>
          <dependency>
              <groupId>com.baomidou</groupId>
              <artifactId>mybatis-plus-boot-starter</artifactId>
              <version>3.2.0</version>
          </dependency>
          <dependency>
              <groupId>org.projectlombok</groupId>
              <artifactId>lombok</artifactId>
          </dependency>
          <!-- https://mvnrepository.com/artifact/p6spy/p6spy -->
          <dependency>
              <groupId>p6spy</groupId>
              <artifactId>p6spy</artifactId>
              <version>3.8.0</version>
          </dependency>
          <dependency>
              <groupId>com.h2database</groupId>
              <artifactId>h2</artifactId>
              <scope>runtime</scope>
          </dependency>
  ​
          <dependency>
              <groupId>com.alibaba</groupId>
              <artifactId>fastjson</artifactId>
              <version>1.2.49</version>
              <scope>test</scope>
          </dependency>
          <!-- for testing -->
          <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-test</artifactId>
              <scope>test</scope>
          </dependency>
          <dependency>
              <groupId>com.alibaba</groupId>
              <artifactId>fastjson</artifactId>
              <version>RELEASE</version>
              <scope>compile</scope>
          </dependency>
      </dependencies>

• application.yml

  spring:
    datasource:
      driver-class-name: com.p6spy.engine.spy.P6SpyDriver
      url: jdbc:p6spy:h2:tcp://192.168.180.115:19200/~/mem/test
      username: root
      password: test
  ​
  # MP 配置
  mybatis-plus:
    type-enums-package: com.mp.sampleenum.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

• 配置类

  @Configuration
  @MapperScan("com.mp.sampleenum.mapper")
  public class MybatisPlusConfig {
  ​
  }

• 实体类

  @EqualsAndHashCode(callSuper = true)
  @Data
  @Accessors(chain = true)
  public class User extends BaseEntity {
  ​
      private String name;
  ​
      private String email;
  ​
      /**
       * IEnum接口的枚举处理
       */
      private AgeEnum age;
  ​
      /**
       * 原生枚举： 默认使用枚举值顺序： 0：MALE， 1：FEMALE
       */
  ​
      private GenderEnum gender;
  ​
      /**
       * 原生枚举（带{@link com.baomidou.mybatisplus.annotation.EnumValue}):
       * 数据库的值对应该注解对应的属性
       */
      @JSONField(serialzeFeatures= SerializerFeature.WriteEnumUsingToString)
      private GradeEnum grade;
  ​
  ​
      private UserState userState;
  ​
  }
  ​
  @Data
  @Accessors(chain = true)
  public class BaseEntity {
    private Long id;
  ​
  }

• 枚举

  @Getter
  public enum AgeEnum implements IEnum<Integer> {
    ONE(1, "一岁"),
    TWO(2, "二岁"),
    THREE(3, "三岁");
  ​
    private final int value;
    private final String desc;
  ​
    AgeEnum(final int value, final String desc) {
      this.value = value;
      this.desc = desc;
    }
  ​
    @Override
    public Integer getValue() {
      return value;
    }
  }
  ​
  ​
  public enum GenderEnum {
      MALE,
      FEMALE;
  }
  ​
  @Getter
  //@JSONType(serializeEnumAsJavaBean = true)
  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;
      @EnumValue
      private final String descp;
  ​
  }
  ​
  ​
  @Getter
  public enum UserState implements IBaseEnum<Integer> {
  ​
      ACTIVE(1, "A"),
      INACTIVE(2, "I");
  ​
      private final int state;
      private final String descp;
  ​
      UserState(int state, String descp) {
          this.state = state;
          this.descp = descp;
  ​
      }
  ​
      @Override
      public Integer getValue() {
          return state;
      }
  ​
      @Override
      public String getDescription() {
          return descp;
      }
  }
  ​
  public interface IBaseEnum<T extends Serializable> extends IEnum<T>{
  ​
      String getDescription();
  }

  注：推荐加注解的方式，GradeEnum这个枚举想要插入String类型，用Fastjson进行序列化。

• 测试类

  @SpringBootTest
  class SampleEnumApplicationTests {
  ​
      @Resource
      private UserMapper mapper;
  ​
      @Test
      public void insert() {
          User user = new User();
          user.setName("K神");
          user.setAge(AgeEnum.ONE);
          user.setGrade(GradeEnum.HIGH);
          user.setGender(GenderEnum.MALE);
          user.setEmail("abc@mp.com");
          user.setUserState(UserState.ACTIVE);
          Assert.assertTrue(mapper.insert(user) > 0);
          // 成功直接拿会写的 ID
          System.err.println("\n插入成功 ID 为：" + user.getId());
  ​
          List<User> list = mapper.selectList(null);
          for (User u : list) {
              System.out.println(u);
              Assert.assertNotNull("age should not be null", u.getAge());
              if (u.getId().equals(user.getId())) {
                  Assert.assertNotNull("gender should not be null", u.getGender());
                  Assert.assertNotNull("grade should not be null", u.getGrade());
  ​
              }
          }
      }
  ​
      @Test
      public void delete() {
          Assert.assertTrue(mapper.delete(new QueryWrapper<User>()
                  .lambda().eq(User::getAge, AgeEnum.TWO)) > 0);
      }
  ​
      @Test
      public void update() {
          Assert.assertTrue(mapper.update(new User().setAge(AgeEnum.TWO),
                  new QueryWrapper<User>().eq("age", AgeEnum.THREE)) > 0);
      }
  ​
      @Test
      public void select() {
          User user = mapper.selectOne(new QueryWrapper<User>().lambda().eq(User::getId, 2));
          Assert.assertEquals("Jack", user.getName());
          Assert.assertTrue(AgeEnum.THREE == user.getAge());
  ​
          //#1500 github: verified ok. Not a bug
          List<User> userList = mapper.selectList(new QueryWrapper<User>().lambda().eq(User::getUserState, UserState.ACTIVE));
          Assert.assertEquals(3, userList.size());
          Optional<User> userOptional = userList.stream()
                  .filter(x -> x.getId() == 1)
                  .findFirst();
          userOptional.ifPresent(user1 -> Assert.assertTrue(user1.getUserState() == UserState.ACTIVE));
      }
  ​
  }

• 测试结果

   Consume Time：0 ms 2019-10-31 14:42:38
   Execute SQL：INSERT INTO user ( id, gender, user_state, grade, name, age, email ) VALUES ( 1189794788921081858, 0, 1, '高中', 'K神', 1, 'abc@mp.com' )
  ​
  ​
  插入成功 ID 为：1189794788921081858
   Consume Time：6 ms 2019-10-31 14:42:38
   Execute SQL：SELECT id,gender,user_state,grade,name,age,email FROM user
  ​