异常：Associations marked as mappedBy must not define database mappings like @JoinTable or @JoinColumn
hibernate升级到3.5版本或者更新的版本时出现这样的异常，举个例子：
private List<User> user;
@OneToMany(fetch = FetchType.LAZY, mappedBy = "dept")
@JoinColumn(name = "dept_id")
public List<User> getUser() {
return user;
}
public void setUser(List<User> user) {
this.user = user;
}
在3.5版本之后@JoinColumn与mappingBy是互斥的，而在更早版本的hibernate是允许这两个互相存在。所以升级到hibernate3.5之后，mappBy="dept",就应该去掉，正确的写法如下：
private List<User> user;
@OneToMany(fetch = FetchType.LAZY)
@JoinColumn(name = "dept_id")
public List<User> getUser() {
return user;
}
public void setUser(List<User> user) {
this.user = user;
}