一 通用枚舉
解決了繁瑣的配置，讓 mybatis 優雅的使用枚舉屬性！
自
3.1.0開始,可配置默認枚舉處理類來省略掃描通用枚舉配置 默認枚舉配置
升級說明:
3.1.0以下版本改變了原生默認行為,升級時請將默認枚舉設置為EnumOrdinalTypeHandler
實體中使用原生枚舉
其他說明:
配置枚舉包掃描的時候能提前注冊使用注解枚舉的緩存
推薦配置:
使用實現
IEnum接口
推薦配置
defaultEnumTypeHandler使用注解枚舉處理
推薦配置
typeEnumsPackage注解枚舉處理與
IEnum接口
推薦配置
typeEnumsPackage與原生枚舉混用
需配置
defaultEnumTypeHandler與typeEnumsPackage
申明通用枚舉屬性
方式一： 使用 @EnumValue 注解枚舉屬性 完整示例
public enum GradeEnum { PRIMARY(1, "小學"), SECONDORY(2, "中學"), HIGH(3, "高中"); GradeEnum(int code, String descp) { this.code = code; this.descp = descp; } @EnumValue//標記數據庫存的值是code private final int code; //。。。 }
方式二： 枚舉屬性，實現 IEnum 接口如下：
public enum AgeEnum implements IEnum<Integer> { ONE(1, "一歲"), TWO(2, "二歲"), THREE(3, "三歲"); private int value; private String desc; @Override public Integer getValue() { return this.value; } }
實體屬性使用枚舉類型
public class User{ /** * 名字 * 數據庫字段: name varchar(20) */ private String name; /** * 年齡，IEnum接口的枚舉處理 * 數據庫字段：age INT(3) */ private AgeEnum age; /** * 年級，原生枚舉（帶{@link com.baomidou.mybatisplus.annotation.EnumValue}): * 數據庫字段：grade INT(2) */ private GradeEnum grade; }
二 代碼
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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之前版本問題默認將枚舉注冊為EnumOrdinalTypeHandler,這是錯誤的方式,默認是 org.apache.ibatis.type.EnumTypeHandler # 如果項目之中實體統一使用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只對注解方式的枚舉處理能提前加載緩存. default-enum-type-handler: org.apache.ibatis.type.EnumOrdinalTypeHandler
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配置類
@Configuration @MapperScan("com.mp.sampleenum.mapper") public class MybatisPlusConfig { }
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實體類
@EqualsAndHashCode(callSuper = true) @Data @Accessors(chain = true) public class User extends BaseEntity { private String name; private String email; /** * IEnum接口的枚舉處理 */ private AgeEnum age; /** * 原生枚舉： 默認使用枚舉值順序： 0：MALE， 1：FEMALE */ private GenderEnum gender; /** * 原生枚舉（帶{@link com.baomidou.mybatisplus.annotation.EnumValue}): * 數據庫的值對應該注解對應的屬性 */ @JSONField(serialzeFeatures= SerializerFeature.WriteEnumUsingToString) private GradeEnum grade; private UserState userState; } @Data @Accessors(chain = true) public class BaseEntity { private Long id; }
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枚舉
@Getter public enum AgeEnum implements IEnum<Integer> { ONE(1, "一歲"), TWO(2, "二歲"), THREE(3, "三歲"); 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, "小學"), SECONDORY(2, "中學"), 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：推薦加注解的方式，GradeEnum這個枚舉想要插入String類型，用Fastjson進行序列化。
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測試類
@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); // 成功直接拿會寫的 ID System.err.println("\n插入成功 ID 為：" + 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)); } }