LocalDateTime的JPA AttributeConverter

Question

我正在密切關注這些帖子（https://www.thoughts-on-java.org/persist-localdate-localdatetime-jpa/,https://github.com/lbtc-xxx/jpa21converter）以實現從JPA 2.1 sql.Timestamp到LocalDateTime的轉換器，反之亦然。

但是，它看起來像我的轉檯不起作用。它似乎從來沒有被稱爲sysout不打印任何東西。

這是我的轉換器：

import java.sql.Timestamp; 
import java.time.LocalDateTime; 

import javax.persistence.AttributeConverter; 
import javax.persistence.Converter; 

@Converter(autoApply = true) 
public class LocalDateTimeConverter implements AttributeConverter<LocalDateTime, Timestamp>{ 

    @Override 
    public Timestamp convertToDatabaseColumn(LocalDateTime localDateTime) { 
     System.out.println("CONVERTER TIMESTAMPS: " + localDateTime); 
     return (localDateTime == null ? null : Timestamp.valueOf(localDateTime)); 
    } 

    @Override 
    public LocalDateTime convertToEntityAttribute(Timestamp timestamp) { 
     System.out.println("CONVERTER TIMESTAMPS: " + timestamp); 
     return (timestamp == null ? null : timestamp.toLocalDateTime()); 
    } 

} 

這是實體類

@Entity 
@Table(name = "survey") 
public class Question { 
    @Id 
    @GeneratedValue(strategy = Generationtype.AUTO) 
    private Integer id; 
    ... 
    @JsonSerialize(using = LocalDateTimeSerializer.class) 
    @JsonDeserialize(using = LocalDateTimeDeserializer.class) 
    /*I also tried here: @Convert(converter = LocalDateTimeConverter.class))*/ 
    private LocalDateTime createdAt; 
    ... 
} 

這是我在5月DAO類方法：

TypedQuery<Question> query = em.createQuery("SELECT q FROM Question q", Question.class); 
query.getResultList().forEach(question -> { 
    LOGGER.info("{}|{}|{}", question.getId(), question.getDescription(), question.getCreatedAt()); 
}); 

return query.getResultList(); 

這會打印出：

1|hello|null 
2|hi|null 
3|howdy|null 

預先感謝您。

Answer 1

我現在工作。我刪除

短暫

從

private transient LocalDateTime createdAt; 

因爲類實現Serializable，這就是爲什麼我把它放在第一SonarLint是需要它。