如何使用JPA持久化LocalDate?

j2cgzkjk  于 2023-10-20  发布在  Spring
关注(0)|答案(5)|浏览(173)

我想在数据库中存储没有时间的日期。所以,我选择使用LocalDate类型。
如本文所述:How to persist LocalDate and LocalDateTime with JPA 2.1,我使用JPA转换器将LocalDate转换为Date
然而,当我想持久化实体(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]
    • 验证码**
  • 转换 *
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"*
private DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");
MyObject myobject = new MyObject(LocalDate.parse("2019-03-01", formatter));

谢谢你的帮助

    • 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"]>
ogq8wdun

ogq8wdun1#

在JPA 2.2中,您不再需要使用转换器,它增加了对以下java.time类型Map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;
ds97pgxw

ds97pgxw2#

JPA 2.2支持LocalDate,因此不需要转换器。
Hibernate从5.3版本开始也支持它。
看看这篇文章:What’s new in JPA 2.2 – Java 8 Date and Time Types了解更多详情。

webghufk

webghufk3#

JPA 2.2增加了对MapJava 8日期/时间API的支持,如LocalDateLocalTimeLocalDateTimeOffsetDateTimeOffsetTime
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
}

注意,subscribedOn属性是一个LocalDate Java对象。
当持久化UserAccount时:

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LocalDate是从数据库中正确获取的:

UserAccount userAccount = entityManager.find(
    UserAccount.class, 1L
);

assertEquals(
    LocalDate.of(
        2013, 9, 29
    ),
    userAccount.getSubscribedOn()
);
w9apscun

w9apscun4#

Hibernate 5支持java 8,所以你可以把它添加到你的pom.xml中:

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-java8</artifactId>
    <version>5.1.0.Final</version>
</dependency>

这为您提供了LocalDateLocalDateTime的Map。

相关问题