Question

我想创建和删除 ProductPrice 之一，更新工作正常，但其他人提供异常

产品类别

public class Product extends GenericEntity {
    @OneToMany(fetch=FetchType.EAGER, mappedBy = "product", targetEntity = ProductPrice.class, cascade = {CascadeType.ALL}, orphanRemoval=true)
    @Fetch(FetchMode.SUBSELECT)    
    @Cache(usage = CacheConcurrencyStrategy.READ_WRITE, region="ncStandardElements")
    private List<ProductPrice> productPrices = new ArrayList<ProductPrice>();

    @OneToMany(fetch=FetchType.EAGER, mappedBy = "product", targetEntity = ProductPrice.class)
    @Fetch(FetchMode.SUBSELECT)    
    @MapKeyJoinColumn(name="CURRENCY_ID")
    @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE, region="ncStandardElements")
    private Map<Currency, ProductPrice> productPriceMap = new HashMap<Currency, ProductPrice>();
}

PRODUCTPRICE CLASS

public class ProductPrice extends GenericEntitySimple {

    @ManyToOne(targetEntity = Product.class, optional=false)
    @JoinColumn(name = "PRODUCT_ID", referencedColumnName = "ID")
    private Product product;
}




public void removeProductPrice(ProductPrice price){
    Product p = price.getProduct();
    //Map<Currency, ProductPrice> productPriceMap = p.getProductPriceMap();
    //productPriceMap.remove(price);

    List<ProductPrice> prices = p.getProductPrices();
    prices.remove(price);
    p.setProductPrices(prices);
    productDao.merge(p);
}

如果在同一会话中创建了价格，则删除操作成功，但是，如果它在当前会话之前创建，则会抛出此错误：

Jun 13, 2013 3:26:29 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet appServlet threw exception
org.hibernate.ObjectNotFoundException: No row with the given identifier exists: [com.netasoft.commerce.framework.catalog.model.ProductPrice#220]
    at org.hibernate.impl.SessionFactoryImpl$2.handleEntityNotFound(SessionFactoryImpl.java:435)
    at org.hibernate.event.def.DefaultLoadEventListener.load(DefaultLoadEventListener.java:233)
    at org.hibernate.event.def.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:285)
    at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:152)
    at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:1090)

我没有完全得到MapKeyJoinColumn，我找不到有关这种情况的文档。我认为Map列出缓存会导致此错误。任何准备充分的文档建议也会得到批准。

Answer 1

我假设在调用removeProductPrice()之前你打开一个会话并开始一个交易。

在removeProductPrice()方法中，通过执行get（）将productPrice对象加载到持久性上下文。像，

ProductPrice price = productPriceDao.get(price.getPriceId());

// Then your logic to delete.

我怀疑传递给ProductPrice方法的removeProductPrice()对象不存在于会话的持久化上下文中。

是否可以发布完整的堆栈跟踪，显示导致异常的确切行。

Answer 2

我找到的最后一个解决方案是;

真正的问题是同一个对象是在两个不同的列表缓存中。因此，当您更改其中一个时，它会根据您选择的FetchType方法导致错误。

如果您将FetchTypes定义为 FetchType.Eager ， FetchType.SUBSELECT 和 CacheConcurrencyStrategy.READ_WRITE ，则可以通过更改两个对象来轻松实现缓存的一面！即你要删除其中一个价格，你应该从productPriceMap＆amp; productPrices也是。然后merge product;它已经完成了！

    @OneToMany(fetch=FetchType.EAGER, mappedBy = "product", targetEntity = ProductPrice.class, cascade = {CascadeType.ALL}, orphanRemoval=true)
    @Fetch(FetchMode.SUBSELECT)    
    @Cache(usage = CacheConcurrencyStrategy.READ_WRITE, region="ncStandardElements")
    private List<ProductPrice> productPrices = new ArrayList<ProductPrice>();

    @OneToMany(fetch=FetchType.EAGER, mappedBy = "product", targetEntity = ProductPrice.class)
    @Fetch(FetchMode.SUBSELECT)    
    @MapKeyJoinColumn(name="CURRENCY_ID")
    @Cache(usage = CacheConcurrencyStrategy.READ_WRITE, region="ncStandardElements")
    private Map<Currency, ProductPrice> productPriceMap = new HashMap<Currency, ProductPrice>();

CRUD ON SERVICE

public void removeProductPrice(ProductPrice price){
    Product p = price.getProduct();
    Map<Currency, ProductPrice> productPriceMap = p.getProductPriceMap();
    productPriceMap.remove(price);

    List<ProductPrice> prices = p.getProductPrices();
    prices.remove(price);
    p.setProductPrices(prices);

    p.removeProductPriceMap(price);

    productDao.merge(p);
}

public void saveProductPrice(ProductPrice price, boolean isNew){
    Product p = price.getProduct();
    List<ProductPrice> prices = p.getProductPrices();
    if(isNew ){
        prices.add(price);
    }
    else{
        int i = 0;
        for (ProductPrice tp: prices){
            if (tp.getId() == price.getId()){
                prices.set(i, price);
                break;
            }
            i++;
        }
    }

    p.setProductPrices(prices);
    productDao.merge(p);
}

Java Hibernate JPA删除OneToMany Relation和MapKeyJoinColumn关系对象

2 个答案: