调用dao后,实体属性没有改变。findByID(id)

这里的问题是,为什么在调用实体的一些setter后不保存实体属性。通常,在更改托管实体的属性时,它应该传播到数据库。

看看这个例子:

@Service
public class SystemServiceImpl implements SystemService {

@Autowired
private SystemDao systemDao;


@Override
@Transactional
public System replace(Long systemID) {

    // External system to replace
    System system = systemDao.findByID(systemID);
    if (null != system) {
        system.setName("Test"); // Calling findByID again shows that this call did not have any effect.
    }
    return system;
}

}

-

@Entity
@Table(name = "db.system")
public class System {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long systemID;

private String name;

@OneToMany(mappedBy = "system", fetch = FetchType.LAZY)
@JsonIgnore
private List<Customer> customers = new ArrayList<Customer>();

public Long getSystemID() {
    return systemID;
}

public void setSystemID(Long systemID) {
    this.systemID = systemID;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public List<Customer> getCustomers() {
    return customers;
}

public void setCustomers(List<Customer> customers) {
    this.customers = customers;
}
}

如果我叫systemDao。在系统后合并。然后将其保存到数据库。我觉得我不应该调用merge,因为它应该是一个托管实体。

我试着用带有@Transactional和不带@Transactional的replace方法,两者都产生了相同的结果。

有什么想法吗?