Elastic实战：彻底解决spring-data-elasticsearch日期、时间类型数据读取报错问题
0. 引言
在使用spring-data-elasticsearch读取es中时间类型的数据时出现了日期转换报错，不少初学者会在这里困惑很久，所以今天我们专门来解读该问题的几种解决方案。
1. 问题分析
该问题的报错形式一般是：
Failed to convert from type [java.lang.String] to type [java.util.Date] for value '2022-03-15T14:31:55+08:00'; nested exception is java.lang.IllegalArgumentException"
当然时间类型的表现形式不一定是我这里的2022-03-15T14:31:55+08:00，可能多种多样，但解决办法都是一致的。
该问题的原因很简单，就是es中存储的时间格式是该种类型的，使用java client去获取时，无法直接转换为时间类型
2. 问题解决
这里演示的环境版本是如下所示。如果在实操时发现部分代码不可用，注意检查版本
spring-data-elasticsearch3.2.12.RELEASE
2.1 es mapping与实体类中声明相同的时间格式
第一种方案，是我们应该在实体类和索引mapping创建前就做好的，将es mapping中的时间字段的格式与实体类中保持统一
1、es mapping中设置时间格式，如果有多种格式中间用||隔开
PUT date_custom { "mappings": { "properties": { "create_time": { "type": "date", "format": "yyyy-MM-dd HH:mm:ss || yyyy-MM-dd'T'HH:mm:ss'+08:00' || strict_date_optional_time || epoch_millis" } } } }
2、实体类中同样声明该时间格式
@Data @Document(indexName = "date_custom",shards = 1, replicas = 0) public class DateTest implements Serializable { @Field(type = FieldType.Date, name = "create_time",format = {}, pattern = "yyyy-MM-dd HH:mm:ss || yyyy-MM-dd'T'HH:mm:ss'+08:00' || strict_date_optional_time || epoch_millis") private Date createTime; // 旧版本 // @Field(type = FieldType.Date, name = "create_time",format = DateFormat.custom, pattern = "yyyy-MM-dd HH:mm:ss || yyyy-MM-dd'T'HH:mm:ss'+08:00' || strict_date_optional_time || epoch_millis") // private Date createTime; }
es自带的时间格式，可以在官方文档中找到
2.2 配置日期格式转换器
1、ElasticsearchRestTemplate的构造方法中提供了一个构造方法，可以传入指定的EntityMapper
@Bean public ElasticsearchRestTemplate elasticsearchRestTemplate(RestHighLevelClient elasticsearchClient,EntityMapper entityMapper){ return new ElasticsearchRestTemplate(elasticsearchClient,entityMapper); }
2、EntityMapper有两个实现类，其中ElasticsearchEntityMapper实现类提供了一个自定义转换器的方法setConversions
@Bean @Override public EntityMapper entityMapper() { ElasticsearchEntityMapper entityMapper = new ElasticsearchEntityMapper(elasticsearchMappingContext(), new DefaultConversionService()); entityMapper.setConversions(elasticsearchCustomConversions()); return entityMapper; }
3、通过该方法我们可以将我们自定义的转换器StringToDateConverter传入进去
@Override public ElasticsearchCustomConversions elasticsearchCustomConversions(){ List<Converter<?,?>> converterList = Lists.newArrayList(StringToDateConverter.INSTANT); return new ElasticsearchCustomConversions(converterList); }
4、完整代码
import com.google.common.collect.Lists; import org.elasticsearch.client.RestHighLevelClient; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.core.convert.support.DefaultConversionService; import org.springframework.core.convert.converter.Converter; import org.springframework.data.elasticsearch.client.ClientConfiguration; import org.springframework.data.elasticsearch.client.RestClients; import org.springframework.data.elasticsearch.config.AbstractElasticsearchConfiguration; import org.springframework.data.elasticsearch.core.ElasticsearchEntityMapper; import org.springframework.data.elasticsearch.core.ElasticsearchRestTemplate; import org.springframework.data.elasticsearch.core.EntityMapper; import org.springframework.data.elasticsearch.core.convert.ElasticsearchCustomConversions; import org.springframework.data.elasticsearch.repository.config.EnableElasticsearchRepositories; import org.springframework.http.HttpHeaders; import org.springframework.lang.NonNull; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Date; import java.util.List; @Configuration @EnableElasticsearchRepositories(basePackages = "com.example.datedemo") public class ElasticRestClientConfig extends AbstractElasticsearchConfiguration { @Value("${spring.elasticsearch.rest.uris}") private String url; @Value("${spring.elasticsearch.rest.username}") private String username; @Value("${spring.elasticsearch.rest.password}") private String password; @Override @Bean public RestHighLevelClient elasticsearchClient() { url = url.replace("http://",""); HttpHeaders headers = new HttpHeaders(); headers.setBasicAuth(username,password); final ClientConfiguration clientConfiguration = ClientConfiguration.builder() .connectedTo(url) .withDefaultHeaders(headers) .build(); return RestClients.create(clientConfiguration).rest(); } @Bean public ElasticsearchRestTemplate elasticsearchRestTemplate(RestHighLevelClient elasticsearchClient,EntityMapper entityMapper){ return new ElasticsearchRestTemplate(elasticsearchClient,entityMapper); } /** * 指定EntityMapper为ElasticsearchEntityMapper * 解决es mapper映射实体类问题 * @return */ @Bean @Override public EntityMapper entityMapper() { ElasticsearchEntityMapper entityMapper = new ElasticsearchEntityMapper(elasticsearchMappingContext(), new DefaultConversionService()); entityMapper.setConversions(elasticsearchCustomConversions()); return entityMapper; } /** * 指定日期转换器，解决日期转换错误问题 * @return */ @Override public ElasticsearchCustomConversions elasticsearchCustomConversions(){ List<Converter<?,?>> converterList = Lists.newArrayList(StringToDateConverter.INSTANT); return new ElasticsearchCustomConversions(converterList); } /** * 字符串转换日期 */ private enum StringToDateConverter implements Converter<String, java.util.Date> { /** * 转换器实例 */ INSTANT; @Override public Date convert(@NonNull String source) { try { return new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'+08:00'").parse(source); } catch (ParseException e) { e.printStackTrace(); } return null; } } }
2.3 @DateTimeFormat注解声明格式（不生效）
首先说明一下这种方式并不生效，这里单独说明是为了列举出来，让大家避免走弯路。
该种方法的原理是通过在注解中声明自定义格式来实现格式转换，但实际上这并不起作用，因为spring-data-elasticsearch会忽略@DateTimeFormat注解
@JsonFormat(pattern="yyyy-MM-dd HH:mm:ss",timezone = "GMT+8") //返回时间类型 @DateTimeFormat(pattern="yyyy-MM-dd HH:mm:ss") //接收时间类型 private Date startTime;
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1、my es mapping
PUT test001 { "mappings": { "properties": { "order_count": { "type": "long" }, "pay_amount_sum": { "type": "double" }, "shop_id": { "type": "long" }, "statistic_time": { "type": "date", "format": "yyyy-MM-dd HH:mm:ss || strict_date_optional_time || epoch_millis" } } } }
2、my java model code
@JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8") @Field(value = "create_time", type = FieldType.Date, format = DateFormat.epoch_millis) private Date createTime;
3、my exception
Unable to convert value '2022-05-23 14:49:24' to java.util.Date for property 'createTime'
4、my change
@JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8") @Field(value = "create_time", type = FieldType.Date, format = {}, pattern = "yyyy-MM-dd HH:mm:ss || strict_date_optional_time || epoch_millis") private Date createTime;
