我有一个一对多的类别-产品关系:
public class **Category**{
@Version
private Integer version;
@OneToMany(mappedBy = "category", cascade = {CascadeType.ALL})
//@OptimisticLock(excluded = true)
private List<Product> products
....
}
和多对一方面:
public class **Product**{
@Version
private Integer version;
@ManyToOne
@JoinColumn(name = "category_id")
@ForeignKey(name = "fk_category_product")
//@OptimisticLock(excluded = true)
private Category category
....
}
我想防止丢失修改,所以我如上所述定义了一个版本机制(并发控制)。
但是当我想保存我的父实体(类别)时,出现以下错误:
无法执行语句;SQL [n/a];约束 [约翰.SYS_C0090239];嵌套异常是 org.hibernate.exception.ConstraintViolationException: 不能 执行语句
这是我的行动、服务和道层:
行动
public String save() throws Exception {
try {
categoryManager.saveCategory(category);
}catch (CategoryExistException e){
List<Object> args = new ArrayList<Object>();
args.add(category.getCategoryName());//categoryName is UNIQUE
addActionError(getText("errors.existing.category", args));
return INPUT;
}
}
经理
@Override
public Category saveCategory(Category category) throws CategoryExistException{
if (category.getVersion()==null)
{
// if new category, lowercase categoryId
category.setCategoryName(category.getCategoryName().toLowerCase());
}
try {
return categoryDao.saveCategory(category);
} catch (final Exception e) {
e.printStackTrace();
log.warn(e.getMessage());
throw new CategoryExistException("Category '" + category.getCategoryName() + "' already exists!");
}
}
道
@Override
public Category saveCategory(Category category){
if (log.isDebugEnabled()) {
log.debug("category's id: " + category.getCategoryId());
}
getSession().saveOrUpdate(category);
//getSession().merge(category);
// necessary to throw a DataIntegrityViolation and catch it in CategoryManger
getSession().flush();
return category;
}
您的问题与乐观锁定无关。由于 SQL JOHN.SYS_C0090239
约束,你会得到一个ConstraintViolationException
。