使用Spring数据JPA进行凝乳操作。在控制器中收到Exception occurred消息。请找到相同的代码。附上堆栈跟踪。
购买课程：
@Entity
@Table(name="purchases")
public class Purchases {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long orderId;
@Temporal(TemporalType.TIMESTAMP)
private Date creation_time;
@Column(name="user_id")
private Long userId;
@Column(name="isbn")
private Long isbn;
@OneToOne(fetch = FetchType.LAZY)
@JoinColumn(name="user_id",insertable=false, updatable=false)
private User user;
@OneToOne(fetch = FetchType.LAZY)
@JoinColumn(name="isbn",insertable=false, updatable=false)
private Books book;
//setters and getters
}
购买存储库 -
@Transactional
public interface PurchasesRepository extends CrudRepository<Purchases, Long>{
List<Purchases> findByUserId(Long userId);
List<Purchases> findByIsbn(Long isbn);
}
购买控制器 -
@RequestMapping(value="/purchase",method=RequestMethod.POST)
public @ResponseBody Purchases purchase(@RequestBody Purchases purchases)throws Exception{
Books book=null;
User user=null;
Purchases purchase=null;
Date creation_date=new Date();
if(purchases.getOrderId()==null){
//check whether book exists in the database
book=booksDAO.findOne(purchases.getIsbn());
user=userDAO.findOne(purchases.getUserId());
if(book==null || user==null){
throw new Exception("Entered book isbn or user id not found !!!");
}
System.out.println(">>>>>>>>>>>> Book and user exists in the databse <<<<<<<<<<<<<<<<");
System.out.println(">>> user.getId()=["+user.getId()+"]>>>>>> book.getIsbn()=["+book.getIsbn());
System.out.println("<<< purchaseDAO.findByUserId(user.getId())="+purchaseDAO.findByUserId(user.getId())+"<<<<<<<purchaseDAO.findByIsbn(book.getIsbn())="+purchaseDAO.findByIsbn(book.getIsbn()));
//check for book already purchase by the customer
if(purchaseDAO.findByUserId(user.getId())!=null){
if(purchaseDAO.findByIsbn(book.getIsbn())==null){
purchase = new Purchases(null,creation_date,purchases.getUserId(),purchases.getIsbn());
purchaseDAO.save(purchase);
purchase.setBook(book);
purchase.setUser(user);
}else{ //checking of the isbn
throw new Exception("Book already purchased !!!");
}
}else{ //checking fo the user existing
purchase = new Purchases(null,creation_date,purchases.getUserId(),purchases.getIsbn());
purchaseDAO.save(purchase);
purchase.setBook(book);
purchase.setUser(user);
}
}else{ //first if checking
throw new Exception(" Order_id already used !!! ");
}
return purchase;
}
购买控制器类 -
@RequestMapping(value="/purchase",method=RequestMethod.POST)
public @ResponseBody Purchases purchase(@RequestBody Purchases purchases)throws Exception{
Books book=null;
User user=null;
Purchases purchase=null;
Date creation_date=new Date();
if(purchases.getOrderId()==null){
//check whether book exists in the database
book=booksDAO.findOne(purchases.getIsbn());
user=userDAO.findOne(purchases.getUserId());
if(book==null || user==null){
throw new Exception("Entered book isbn or user id not found !!!");
}
System.out.println(">>>>>>>>>>>> Book and user exists in the databse <<<<<<<<<<<<<<<<");
System.out.println(">>> user.getId()=["+user.getId()+"]>>>>>> book.getIsbn()=["+book.getIsbn());
System.out.println("<<< purchaseDAO.findByUserId(user.getId())="+purchaseDAO.findByUserId(user.getId())+"<<<<<<<purchaseDAO.findByIsbn(book.getIsbn())="+purchaseDAO.findByIsbn(book.getIsbn()));
//check for book already purchase by the customer
if(purchaseDAO.findByUserId(user.getId())!=null){
if(purchaseDAO.findByIsbn(book.getIsbn())==null){
purchase = new Purchases(null,creation_date,purchases.getUserId(),purchases.getIsbn());
purchaseDAO.save(purchase);
purchase.setBook(book);
purchase.setUser(user);
}else{ //checking of the isbn
throw new Exception("Book already purchased !!!");
}
}else{ //checking fo the user existing
purchase = new Purchases(null,creation_date,purchases.getUserId(),purchases.getIsbn());
purchaseDAO.save(purchase);
purchase.setBook(book);
purchase.setUser(user);
}
}else{ //first if checking
throw new Exception(" Order_id already used !!! ");
}
return purchase;
}
使用spring boot运行应用程序。在第三个system.out行中获取异常。我试图将Purchases类用作Purchases Repository类中的返回类型而不是List，但仍然没有影响。请找到堆栈跟踪。
Hibernate: select user0_.user_id as user_id1_2_0_, user0_.contact as contact2_2_0_, user0_.email as email3_2_0_, user0_.name as name4_2_0_ from user_details user0_ where user0_.user_id=?
>>>>>>>>>>>> Book and user exists in the databse <<<<<<<<<<<<<<<<
>>> user.getId()=[6]>>>>>> book.getIsbn()=[6
Hibernate: select purchases0_.order_id as order_id1_1_, purchases0_.isbn as isbn3_1_, purchases0_.creation_time as creation2_1_, purchases0_.user_id as user_id4_1_ from purchases purchases0_ where purchases0_.user_id=?
Hibernate: select purchases0_.order_id as order_id1_1_, purchases0_.isbn as isbn3_1_, purchases0_.creation_time as creation2_1_, purchases0_.user_id as user_id4_1_ from purchases purchases0_ where purchases0_.isbn=?
<<< purchaseDAO.findByUserId(user.getId())=Exception occurred !!!<<<<<<<purchaseDAO.findByIsbn(book.getIsbn())=Exception occurred !!!
Hibernate: select purchases0_.order_id as order_id1_1_, purchases0_.isbn as isbn3_1_, purchases0_.creation_time as creation2_1_, purchases0_.user_id as user_id4_1_ from purchases purchases0_ where purchases0_.user_id=?
Hibernate: select purchases0_.order_id as order_id1_1_, purchases0_.isbn as isbn3_1_, purchases0_.creation_time as creation2_1_, purchases0_.user_id as user_id4_1_ from purchases purchases0_ where purchases0_.isbn=?
2016-05-05 14:59:47.088 ERROR 12207 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.Exception: Book already purchased !!!] with root cause
答案 0 :(得分：0)
第三个print语句中发生异常，因为purchase模型类是使用toString（）定义的，因为打印异常消息。后来，我想出来并改变并得到了正确的结果。