DetachedCriteria 关联查询?报错

有如下两个实体类:

A.java

public class A{

	private User user;

	@OneToOne(fetch = FetchType.EAGER)
	@JoinColumn(name = "user_id")
	public User getUser() {
		return user;
	}

	public void setUser(User user) {
		this.user= user;
	}

}

public class User{
	private Integer id;
	private String name;

	getter and setter...
}

怎么用DetachedCriteria 查询A.java中user.name = "a"的数据??

dc.add(Restrictions.like("user.name", "a"));

这样查询要报错:

org.hibernate.QueryException: could not resolve property: user.name of: com.thon.entity.health.Task
at