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("
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
​

     

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原文地址：https://www.cnblogs.com/dalianpai/p/11771269.html