[英]How to persist LocalDate with JPA?
我想将没有时间的日期存储到我的数据库中。 所以,我选择使用LocalDate
类型。
如本文所述,我使用 JPA 转换器将LocalDate
转换为Date
。
但是,当我想保留我的实体(使用 POST 和 PUT 请求)时,我遇到了一些麻烦。
错误
2019-02-23 11:26:30.254 WARN 2720 --- [-auto-1-exec-10] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Expected array or string.; nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Expected array or string.
at [Source: (PushbackInputStream); line: 1, column: 104] (through reference chain: ...entity.MyObject["startdate"])]
org.springframework.http.converter.HttpMessageConversionException: Type definition error: [simple type, class org.springframework.http.ResponseEntity]; nested exception is com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of `org.springframework.http.ResponseEntity` (no Creators, like default construct, exist): cannot deserialize from Object value (no delegate- or property-based Creator)
at [Source: (PushbackInputStream); line: 1, column: 2]
代码
转换器
package ...entity;
import javax.persistence.AttributeConverter;
import javax.persistence.Converter;
import java.time.LocalDate;
import java.sql.Date;
@Converter(autoApply = true)
public class LocalDateAttributeConverter implements AttributeConverter<LocalDate, Date> {
@Override
public Date convertToDatabaseColumn(LocalDate locDate) {
return (locDate == null ? null : Date.valueOf(locDate));
}
@Override
public LocalDate convertToEntityAttribute(Date sqlDate) {
return (sqlDate == null ? null : sqlDate.toLocalDate());
}
}
实体
package ...entity;
import org.hibernate.annotations.ColumnDefault;
import javax.persistence.*;
import java.time.LocalDate;
import java.util.HashSet;
import java.util.Set;
@Entity
public class MyObject {
@Id
private String id;
private LocalDate startdate;
private LocalDate enddate;
public MyObject() {}
public MyObject(LocalDate enddate) {
this.startdate = LocalDate.now();
this.enddate = enddate;
}
...
}
“主要的”
private DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");
MyObject myobject = new MyObject(LocalDate.parse("2019-03-01", formatter));
感谢帮助。
编辑 1:打印 MyObject
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
HttpEntity<String> entity = new HttpEntity<>(this.toJsonString(myObject), headers);
System.out.println(entity.toString());
// <{"id":"ba6649e4-6e65-4f54-8f1a-f8fc7143b05a","startdate":{"year":2019,"month":"FEBRUARY","dayOfMonth":23,"dayOfWeek":"SATURDAY","era":"CE","dayOfYear":54,"leapYear":false,"monthValue":2,"chronology":{"id":"ISO","calendarType":"iso8601"}},"enddate":{"year":2019,"month":"MARCH","dayOfMonth":1,"dayOfWeek":"FRIDAY","era":"CE","dayOfYear":60,"leapYear":false,"monthValue":3,"chronology":{"id":"ISO","calendarType":"iso8601"}}},[Content-Type:"application/json"]>
使用 JPA 2.2,您不再需要使用转换器,它添加了对以下 java.time 类型映射的支持:
java.time.LocalDate
java.time.LocalTime
java.time.LocalDateTime
java.time.OffsetTime
java.time.OffsetDateTime
@Column(columnDefinition = "DATE")
private LocalDate date;
@Column(columnDefinition = "TIMESTAMP")
private LocalDateTime dateTime;
@Column(columnDefinition = "TIME")
private LocalTime localTime;
Hibernate 5 支持 java 8,因此您可以将其添加到 pom.xml:
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-java8</artifactId>
<version>5.1.0.Final</version>
</dependency>
这为您提供了开箱即用的LocalDate
和LocalDateTime
映射。
JPA 2.2增加了对映射Java 8日期/时间API,像支持LocalDate
, LocalTime
, LocalDateTime
, OffsetDateTime
或OffsetTime
。
因此,让我们假设我们有以下实体:
@Entity(name = "UserAccount")
@Table(name = "user_account")
public class UserAccount {
@Id
private Long id;
@Column(name = "first_name", length = 50)
private String firstName;
@Column(name = "last_name", length = 50)
private String lastName;
@Column(name = "subscribed_on")
private LocalDate subscribedOn;
//Getters and setters omitted for brevity
}
请注意, subscribedOn
属性是一个LocalDate
Java 对象。
持久化UserAccount
:
UserAccount user = new UserAccount()
.setId(1L)
.setFirstName("Vlad")
.setLastName("Mihalcea")
.setSubscribedOn(
LocalDate.of(
2013, 9, 29
)
);
entityManager.persist(user);
Hibernate 生成正确的 SQL INSERT 语句:
INSERT INTO user_account (
first_name,
last_name,
subscribed_on,
id
)
VALUES (
'Vlad',
'Mihalcea',
'2013-09-29',
1
)
在获取UserAccount
实体时,我们可以看到从数据库中正确获取了LocalDate
:
UserAccount userAccount = entityManager.find(
UserAccount.class, 1L
);
assertEquals(
LocalDate.of(
2013, 9, 29
),
userAccount.getSubscribedOn()
);
我认为您可以编写自己的转换器,请检查答案: Spring Data JPA - 从字符串转换日期和/或时间时转换失败
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.