Question

我有一个Spring数据实体（使用JPA w / Hibernate和MySQL）定义如下：

@Entity
@Table(name = "dataset")
public class Dataset {

    @Id
    @GenericGenerator(name = "generator", strategy = "increment")
    @GeneratedValue(generator = "generator")
    private Long id;
    @Column(name = "name", nullable = false)
    private String name;
    @Column(name = "guid", nullable = false)
    private String guid;
    @Column(name = "size", nullable = false)
    private Long size;
    @Column(name = "create_time", nullable = false)
    private Date createTime;
    @OneToOne(optional = false)
    @JoinColumn(name = "created_by")
    private User createdBy;
    @Column(name = "active", nullable = false)
    private boolean active;
    @Column(name = "orig_source", nullable = false)
    private String origSource;
    @Column(name = "orig_source_type", nullable = false)
    private String origSourceType;
    @Column(name = "orig_source_org", nullable = false)
    private String origSourceOrg;
    @Column(name = "uri", nullable = false)
    private String uri;
    @Column(name = "mimetype", nullable = false)
    private String mimetype;
    @Column(name = "registration_state", nullable = false)
    private int registrationState;
    @OneToMany(fetch = FetchType.EAGER, cascade = {CascadeType.ALL})
    @JoinColumn(name = "dataset_id")
    @JsonManagedReference
    private List<DatasetFile> datasetFiles;

我有这个实体的以下存储库：

public interface DatasetRepo extends JpaRepository<Dataset, Long> {

    @Query("SELECT CASE WHEN COUNT(p) > 0 THEN 'true' ELSE 'false' END FROM Dataset p WHERE p.uri = ?1 and p.registrationState>0")
    public Boolean existsByURI(String location);

    @Query("SELECT a FROM Dataset a LEFT JOIN FETCH a.datasetFiles c where a.registrationState>0")
    public List<Dataset> getAll(Pageable pageable);

    @Query("SELECT a FROM Dataset a LEFT JOIN FETCH a.datasetFiles c WHERE a.registrationState>0")
    public List<Dataset> findAll();

    @Query("SELECT a FROM Dataset a LEFT JOIN FETCH a.datasetFiles c where a.guid= ?1")
    public Dataset findByGuid(String guid);
}

现在 - 在一个控制器中，我正在获取一个数据集，更新其中一个属性，我希望将属性更改刷新到DB，但它永远不会。

@RequestMapping(value = "/storeDataset", method = RequestMethod.GET)
    public @ResponseBody
    WebServiceReturn storeDataset(
            @RequestParam(value = "dsGUID", required = true) String datasetGUID,
            @RequestParam(value = "stType", required = true) String stType) {
        WebServiceReturn wsr = null;
        logger.info("stType: '" + stType + "'");
        if (!stType.equals("MongoDB") && !stType.equals("Hive") && !stType.equals("HDFS")) {
            wsr = getFatalWebServiceReturn("Invalid Storage type '" + stType + "'");
        } else if (stType.equals("MongoDB")) {
            /* Here is where I'm reading entity from Repository */
            Dataset dataset = datasetRepo.findByGuid(datasetGUID);
            if (dataset != null) {
                MongoLoader mongoLoader = new MongoLoader();
                boolean success = mongoLoader.loadMongoDB(dataset);
                logger.info("Success: " + success);
                if (success) {
                    /* Here is where I update entity attribute value, this is never flushed to DB */
                    dataset.setRegistrationState(1);
                }
                wsr = getWebServiceReturn(success ? 0 : -1, "Successfully loaded dataset files into " + stType + " storage", "Failed to load dataset files into " + stType + " storage");
            }

        }
        return wsr;
    }

谢谢

Answer 1

您需要使用@Transactional注释请求映射的方法。

为什么呢？如果要修改内存中的对象，然后在数据库中透明地更新，则需要在活动事务中执行此操作。

请勿忘记您正在使用JPA（spring-data正在使用JPA），如果您希望您的实体位于managed state，则需要有效交易

请参阅：

http://www.objectdb.com/java/jpa/persistence/update

透明更新从中检索实体对象数据库（无论哪种方式）都可以简单地在内存中修改来自活跃交易：
Employee employee = em.find(Employee.class, 1);

em.getTransaction().begin();
employee.setNickname("Joe the Plumber");
em.getTransaction().commit();

Spring数据JPA实体更改未被持久化

1 个答案: