Question

我想在addTrasction方法中插入一个具有多个产品的事务，如下所示，事务和产品类之间存在一对多的关系，但是出现此错误非法尝试将集合与两个打开的会话相关联

这是hibernate cofigurtion

  File path2Config= new File("./src/com/config/hibernate.cfg.xml"); 
  SessionFactory sessionfactory=new       
  Configuration().configure(path2Config).buildSessionFactory();
  Session session=sessionfactory.openSession();

保存产品方法

public Product save(Product product){
session.beginTransaction();
session.save(product);
session.getTransaction().commit();
return product;
 }

保存交易方法

public Transaction save(Transaction transaction){
   session.beginTransaction();
session.save(transaction);
session.getTransaction().commit();
return transaction;
 }

addTransaction方法

public void addTrasction(Product product){
    Transaction transaction=new Transaction();

    for(Cart c:list){
        product=new Product();
        product.setProductName(c.getProductName());
        product.setProductPrize(c.getPrize());
        product.setQuantity(c.getQuantity());
        product.setTransaction(transaction);
       product=productDao.save(product);
    }
    Date transactionDate=new Date();
    transaction.setTransactionDate(transactionDate);
    transactionDao.save(transaction);
     }

交易类

  @Entity
  @Table(name="transaction")
  public class Transaction {
@Id
@GenericGenerator(name="autoGen" ,strategy="increment")
@GeneratedValue(generator="autoGen")
@Column(name="transactionId")
private long transactionId;
@Column(name="transactionDate")
private Date transactionDate;
@Column(name="cost")
private double cost;
@OneToMany(mappedBy="transaction")
private List<Product> products=new ArrayList<Product>();

public Transaction()
{   
}
public long getTransactionId() {
    return transactionId;
}
public void setTransactionId(long transactionId) {
    this.transactionId = transactionId;
}
public Date getTransactionDate() {
    return transactionDate;
}
public void setTransactionDate(Date transactionDate) {
    this.transactionDate = transactionDate;
}
public double getCost() {
    return cost;
}
public void setCost(double cost) {
    this.cost = cost;
}
public List<Product> getProducts() {
    return products;
}
public void setProducts(List<Product> products) {
    this.products = products;
}

    }

产品类

  @Entity
  @Table(name="Product")
    public class Product {
@Id
@GenericGenerator(name="autoGen" ,strategy="increment")
@GeneratedValue(generator="autoGen")
@Column(name="productId")
private long productId;
@Column(name="productName")
private String productName;
@Column(name="productPrize")
private double productPrize;
@Column(name="quantity")
private int quantity;
@JoinColumn(name = "transactionId")
   @ManyToOne(cascade = CascadeType.ALL)
Transaction transaction;
public long getProductId() {
    return productId;
}
public void setProductId(long productId) {
    this.productId = productId;
}
public String getProductName() {
    return productName;
}
public void setProductName(String productName) {
    this.productName = productName;
}
public double getProductPrize() {
    return productPrize;
}
public void setProductPrize(double productPrize) {
    this.productPrize = productPrize;
}
public int getQuantity() {
    return quantity;
}
public void setQuantity(int quantity) {
    this.quantity = quantity;
}
public Transaction getTransaction() {
    return transaction;
}
public void setTransaction(Transaction transaction) {
    this.transaction = transaction;
}


   }

Answer 1

将addTrasction方法替换为

public void addTrasction(Product product){
    Transaction transaction=new Transaction();

    for(Cart c:list){
        product=new Product();
        product.setProductName(c.getProductName());
        product.setProductPrize(c.getPrize());
        product.setQuantity(c.getQuantity());
        product.setTransaction(transaction);
       transaction.getProducts().add(product);//here is the change
    }
    Date transactionDate=new Date();
    transaction.setTransactionDate(transactionDate);
    transactionDao.save(transaction);
   }

这样，hibernate将在事务表中执行一个插入，并在产品表中使用正确的FK执行多个插入。

Answer 2

最后我解决了它

将sessionfactory.getCurrentSession更改为sessionfactory.openSession并将addTrasction方法更改为

public void addTrasction(Product product){
    Transaction transaction=new Transaction();
    Date transactionDate=new Date();
    transaction.setTransactionDate(transactionDate);
    for(Cart c:list){
        product=new Product();
        product.setProductName(c.getProductName());
        product.setProductPrize(c.getPrize());
        product.setQuantity(c.getQuantity());
        product.setTransaction(transaction);
        product=productDao.save(product);
    }
    list.clear();

}

非法尝试将集合与两个打开的会话相关联

2 个答案: