(四)springboot 数据枚举类型的处理(从前端到后台数据库)

2024-07-17 16:08| 来源: 网络整理| 查看: 265

枚举

枚举是一个被命名的整型常数的集合，用于声明一组带标识符的常数。枚举在曰常生活中很常见，例如一个人的性别只能是“男”或者“女”，一周的星期只能是 7 天中的一个等。类似这种当一个变量有几种固定可能的取值时，就可以将它定义为枚举类型。

项目案例(直接上代码,做记录参考) 目录结构截图

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BaseEnum 枚举基类接口 package com.example.demo.enums.base; public interface BaseEnum { /** * 根据枚举值和type获取枚举 */ public static T getEnum(Class type, int code) { T[] objs = type.getEnumConstants(); for (T em : objs) { if (em.getCode().equals(code)) { return em; } } return null; } /** * 获取枚举值 * * @return */ Integer getCode(); /** * 获取枚举文本 * * @return */ String getLabel(); } 自定义枚举(以性别为例(女,男,保密)) package com.example.demo.enums; import com.example.demo.enums.base.BaseEnum; public enum SexEnumType implements BaseEnum { WOMEN(0, "女"), MEN(1, "男"), ENCRY(2, "保密"); private Integer code;//枚举值 private String leble;//枚举文本 SexEnumType(Integer code, String leble) { this.code = code; this.leble = leble; } @Override public Integer getCode() { return code; } @Override public String getLabel() { return leble; } } 实体类 package com.example.demo.model.entity; import com.baomidou.mybatisplus.annotation.*; import com.example.demo.enums.EducationType; import com.example.demo.enums.SexEnumType; import com.example.demo.model.baseModel.BaseEntity; import io.swagger.annotations.ApiModel; import io.swagger.annotations.ApiModelProperty; import lombok.Getter; import lombok.Setter; /** *

* *

* * @author gaozhen * @since 2022-12-03 */ @Getter @Setter @TableName("eprk_sm_user") @ApiModel(value = "SmUser对象", description = "") public class SmUser extends BaseEntity { private static final long serialVersionUID = 1L; @ApiModelProperty("用户名称") @TableField("user_name") private String userName; @ApiModelProperty("用户编码") @TableField("user_code") private String userCode; @ApiModelProperty("用户登录密码") @TableField("user_password") private String userPassword; @ApiModelProperty("年龄") @TableField("age") private Integer age; @ApiModelProperty("学历(0小学,1初中,2高中,3大专,4本科,5研究生,6保密)") @TableField("education") private EducationType education; @ApiModelProperty("性别(0:女,1:男,2:保密)") @TableField("sex") private SexEnumType sex; @ApiModelProperty("邮箱地址") @TableField("email") private String email; @ApiModelProperty("手机号") @TableField("phone") private String phone; @ApiModelProperty("地址") @TableField("address") private String address; @ApiModelProperty("备注") @TableField("memo") private String memo; }

注意实体类里的性别字段 ,案例中"学历"也是个枚举.

序列化BaseEnum接口序列化相关代码 package com.example.demo.enums.base; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.databind.JsonSerializer; import com.fasterxml.jackson.databind.SerializerProvider; import java.io.IOException; /** * BaseEnum 序列化 */ public class BaseEnumSerializer extends JsonSerializer { @Override public void serialize(BaseEnum value, JsonGenerator gen, SerializerProvider serializers) throws IOException { gen.writeNumber(value.getCode()); gen.writeStringField(gen.getOutputContext().getCurrentName() + "Text", value.getLabel()); } } 反序列化相关代码 package com.example.demo.enums.base; import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.DeserializationContext; import com.fasterxml.jackson.databind.JsonDeserializer; import com.fasterxml.jackson.databind.JsonNode; import lombok.extern.slf4j.Slf4j; import net.bytebuddy.implementation.bytecode.Throw; import org.apache.commons.lang3.StringUtils; import org.springframework.beans.BeanUtils; import java.io.IOException; /** * BaseEnum反序列化 */ @Slf4j public class BaseEnumDeserializer extends JsonDeserializer { @Override public Enum deserialize(JsonParser p, DeserializationContext ctxt) throws IOException { JsonNode node = p.getCodec().readTree(p); String currentName = p.currentName(); Object currentValue = p.getCurrentValue(); Class findPropertyType = null; findPropertyType = BeanUtils.findPropertyType(currentName, currentValue.getClass()); if (findPropertyType == null) { log.info("在" + currentValue.getClass() + "实体类中找不到" + currentName + "字段"); return null; } String asText = null; asText = node.asText(); if (StringUtils.isBlank(asText) || (StringUtils.isNotBlank(asText) && asText.equals("0"))) { return null; } if (BaseEnum.class.isAssignableFrom(findPropertyType)) { BaseEnum valueOf = null; if (StringUtils.isNotBlank(asText)) { valueOf = BaseEnum.getEnum(findPropertyType, Integer.parseInt(asText)); } if (valueOf != null) { return (Enum) valueOf; } } return Enum.valueOf(findPropertyType, asText); } } 加载相关序列化到bean package com.example.demo.enums.base; import org.springframework.boot.autoconfigure.jackson.Jackson2ObjectMapperBuilderCustomizer; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import java.util.TimeZone; /** * 加载baseEnum 构建bean定义，初始化Spring容器。 */ @Configuration public class EnumBeanConfig { @Bean public Jackson2ObjectMapperBuilderCustomizer jacksonObjectMapperCustomization() { BaseEnumSerializer baseEnumSerializer = new BaseEnumSerializer(); BaseEnumDeserializer baseEnumDeserializer = new BaseEnumDeserializer(); return jacksonObjectMapperBuilder -> jacksonObjectMapperBuilder.timeZone(TimeZone.getDefault()). serializerByType(BaseEnum.class, baseEnumSerializer). deserializerByType(Enum.class, baseEnumDeserializer); } } 表单BaseEnum枚举转换并加载到bean中 package com.example.demo.enums.base; import org.springframework.core.convert.converter.Converter; import org.springframework.core.convert.converter.ConverterFactory; /** * 表单BaseEnum枚举转换 */ public class BaseEnumConverterFactory implements ConverterFactory { @Override public Converter getConverter(Class targetType) { return new BaseEnumConverter(targetType); } public class BaseEnumConverter implements Converter { private Class type; public BaseEnumConverter(Class type) { this.type = type; } @Override public BaseEnum convert(String source) { return BaseEnum.getEnum(type, Integer.parseInt((java.lang.String) source)); } } } 加载到bean package com.example.demo.enums.base; import org.springframework.context.annotation.Configuration; import org.springframework.format.FormatterRegistry; import org.springframework.web.servlet.config.annotation.WebMvcConfigurer; @Configuration public class WebMvcConfigImpl implements WebMvcConfigurer { @Override public void addFormatters(FormatterRegistry registry) { registry.addConverterFactory(new BaseEnumConverterFactory()); } } 测试案例数据库中存的数据

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