Hibernate - 无法更新嵌入式集

Question

我无法更新实体中包含的集合.我没有收到任何错误,但是当我尝试使用一组不同的升级实体更新产品时,数据库的内容保持不变.

我有一个Product实体,其中包含一组Upgrade实体.

@Entity
@Table(name="product")
public class Product {
    private Long id;
    private Set<Upgrade> upgrades;

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="id")
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    @ManyToMany(mappedBy = "products",
                targetEntity = Upgrade.class,
                cascade = CascadeType.ALL,
                fetch = FetchType.EAGER)
    public Set<Upgrade> getUpgrades() {
        return upgrades;
    }

    public void setUpgrades(Set<Upgrade> upgrades) {
        this.upgrades = upgrades;
    }
}

@Entity
@Table(name="upgrade")
public class Upgrade {
    private Long id;
    private Set<Product> products;

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="id")
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    @ManyToMany(targetEntity = Product.class,
                cascade = CascadeType.ALL,
                fetch = FetchType.EAGER)
    @JoinTable(name = "upgrade_product",
               joinColumns = @JoinColumn(name = "upgrade_id"),
               inverseJoinColumns = @JoinColumn(name="product_id"))
    public Set<Product> getProducts() {
        return products;
    }

    public void setProducts(Set<Product> products) {
        this.products = products;
    }
}

这链接到以下数据库结构:

CREATE TABLE `product` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=30 DEFAULT CHARSET=latin1;

CREATE TABLE `upgrade` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=778 DEFAULT CHARSET=latin1;

CREATE TABLE `upgrade_product` (
  `upgrade_id` bigint(20) NOT NULL,
  `product_id` bigint(20) NOT NULL,
  PRIMARY KEY (`upgrade_id`,`product_id`),
  KEY `FK169831CC92B40B3C` (`upgrade_id`),
  KEY `FK169831CC6DAEB65C` (`product_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

当我更改Product.upgrades和调用时,sessionFactory.getCurrentSession().update(product)我没有看到这些更改设置.我相信我在这里遗漏了一些东西,但无法弄清楚它是什么.

这是在MySQL 5数据库中.

我正在更新这样的升级集:

    List<Upgrade> upgradeList = getSelectedUpgrades(editProduct.getAllUpgrades());
    if (compareUpgradeLists(new ArrayList<Upgrade>(product.getUpgrade()), upgradeList) == false) {
        product.setUpgrade(new HashSet<Upgrade>(upgradeList));
        isDirty = true;
    }

    if (isDirty) {
        productDao.update(product);
    }

其中getSelectedUprades是:

private List<Upgrade> getSelectedUpgrades (List<EditProductUpgradeDetails> list) {
        List<Upgrade> upgradeList = new ArrayList<Upgrade>();
        // Update the upgrades for this product
        for (EditProductUpgradeDetails upgradeDetails : list) {
            if (upgradeDetails.getSelected()) {
                // Add upgrade to new upgrade list
                Upgrade upgrade = upgradeDao.get(upgradeDetails.getId());
                upgradeList.add(upgrade);
            }
        }
        return upgradeList;
    }

并且EditProductUpgradeDetails是一个表单备份对象,其中包含selected链接到该升级的复选框的字段.

我已经使用调试器来检查创建的Set是否不同,并且产品包含了Set,但是,当我在会话上调用升级方法时,它无法将该更改传播到数据库.

Answer 1

从来没有,真的永远不会用新的/其他集合替换Hibernate Managed Collection.你总是必须使用原始集合并使用add和remove方法!

永远不要做这样的事情: product.setUpgrade(new HashSet<Upgrade>(upgradeList));

你需要做点什么

class Product {
  ...
  private Set<Upgrade> upgrades;
  ...


  public void replaceUpgrades(Set<Upgrade> newUpgrades) {
     this.upgrades.retainAll(newUpgrades);

     HashSet<T> reallyNew = new HashSet<T>(newUpgrades);
     reallyNew.removeAll(this.upgrades);

     this.upgrades.addAll(reallyNew);
  }

}

如果你使用hibernate进行字段注入,那么最好不要在hibernate维护的集合上设置setter.