当 LocalDate 为 null 时，Java 8 LocalDate JPA 2.2 坚持到 postgresql Date 失败

Question

我想使用 Java8 DateTime API 中的 LocalDate 和 LocalDateTime， 并且在值为 null 时无法坚持到 postgresql date 和 timestamp。

异常信息:

Internal Exception: org.postgresql.util.PSQLException: ERROR: column "some_date" is of type date but expression is of type character varying
hint: You will need to rewrite or cast the expression.
position: 61
Error Code: 0
Call: INSERT INTO TEST (ID, some_date, some_timestamp) VALUES (?, ?, ?)
bind => [0, null, null]
Query: InsertObjectQuery(mypackage.TestEntity@38c9e0d6)

我对 postgresql 驱动程序和 JPA2.2 的 Maven 依赖项:

<dependency>
        <groupId>org.postgresql</groupId>
        <artifactId>postgresql</artifactId>
        <version>42.2.0</version>
</dependency>
<dependency>
        <groupId>org.eclipse.persistence</groupId>
        <artifactId>org.eclipse.persistence.jpa</artifactId>
        <version>2.7.1</version>
</dependency>
<dependency>
        <groupId>org.eclipse.persistence</groupId>
        <artifactId>javax.persistence</artifactId>
        <version>2.2.0</version>
</dependency>

我在 postgresql10.1 的 test 表(没有 not null 约束):

create table test (id serial, some_date date, some_timestamp timestamp);

我的 TestEntity 类:

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import java.time.LocalDate;
import java.time.LocalDateTime;

@Entity(name="test")
public class TestEntity {

    @Id
    private int id;

    @Column(name="some_date")
    private LocalDate someDate;

    @Column(name="some_timestamp")
    private LocalDateTime someTimestamp;

   //simple getters and setters here.
}

我的测试方法:

public void testMethod() {
    TestEntity testEntity = new TestEntity();
    // IF I set both someDate and someTimestamp via setters,
    //I don't get any exceptions (table data will be added successfully)
    em.getTransaction().begin();
    em.persist(testEntity);
    em.getTransaction().commit(); //this is where the exception occurs.
}

我错过了什么？有什么解决方法吗？

编辑: 几个月后，我意识到这个问题不再发生了。可能是因为我将服务器实现从 Grizzly 切换到了 Payara5.181。 毕竟不需要自定义转换器(即使值为 null)。

Answer 1

这看起来像是 eclipselink 中的错误 https://bugs.eclipse.org/bugs/show_bug.cgi?id=535431 .当 LocalDate 值为 null 时，没有合适的 JDBC 类型映射，默认设置为 VARCHAR，驱动程序抛出异常。

作为解决方法，我们创建了具有所需映射的 PatchedPostgreSQLPlatform，并将其设置为 eclipselink.target-database 属性的值。

public class PatchedPostgreSQLPlatform extends PostgreSQLPlatform {

    /**
     * Extended with java.time.* classes mappings.
     */
    @Override
    public int getJDBCType(Class javaType) {
        if (javaType == ClassConstants.TIME_LDATE) {
            return Types.DATE;
        } else if (javaType == ClassConstants.TIME_LTIME) {
            return Types.TIMESTAMP;
        } else if (javaType == ClassConstants.TIME_LDATETIME) {
            return Types.TIMESTAMP;
        } else if (javaType == ClassConstants.TIME_ODATETIME) {
            return Types.TIMESTAMP;
        } else if (javaType == ClassConstants.TIME_OTIME) {
            return Types.TIMESTAMP;
        } else {
            return super.getJDBCType(javaType);
        }
    }

}