Java--hibernate树状映射

1.假设此对象为（组织结构）
package hibernate002test.copy;

import java.util.HashSet;
import java.util.Set;

import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
/**

• 树状映射
• @author Lenovo

*/
@Entity
public class Org {
private int id;
private String name;
private Set<Org> children = new HashSet<Org>();
private Org parent;

@Id
@GeneratedValue
public int getId() {
	return id;
}

public void setId(int id) {
	this.id = id;
}

public String getName() {
	return name;
}

public void setName(String name) {
	this.name = name;
}


@OneToMany(mappedBy = "parent",cascade=CascadeType.ALL,fetch=FetchType.EAGER)//父类与子类相互关联，当树小时可用EAGER
public Set<Org> getChildren() {
	return children;
}

public void setChildren(Set<Org> children) {
	this.children = children;
}

@ManyToOne
@JoinColumn(name="parent_id")
public Org getParent() {
	return parent;
}

public void setParent(Org parent) {
	this.parent = parent;
}

}