一对多注解标识在表示多的集合字段上,多对一的注解标识在一的属性上,你定义的实体类本质是自关联的一对多的类。
按照你描述的需求,使用注解,实例代码如下:
import java.util.ArrayList;
import java.util.List;
public class Organization {
private Integer id;
private String orgnName;
// 父级机构(即上级机构)
private Organization parent;
// 子机构(即所有下级机构)
private List<Organization> children = new ArrayList<Organization>();
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
@Column(nullable = false, unique = true)
public String getOrgnName() {
return orgnName;
}
public void setOrgnName(String name) {
this.orgnName = name;
}
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "parentId")
public Organization getParent() {
return parent;
}
public void setParent(Organization parent) {
this.parent = parent;
}
@OneToMany(targetEntity = Menu.class, cascade = { CascadeType.ALL }, mappedBy = "parentMenu")
@Fetch(FetchMode.SUBSELECT)
@OrderBy("id")
public List<Organization> getChildren() {
return children;
}
public void setChildren(List<Organization> children) {
this.children = children;
}
}