Hibernate的树状结构设计

Org类：

package com.qimiguang.hibernate;

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;

@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(cascade=CascadeType.ALL, mappedBy="parent", fetch=FetchType.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;
 }
}

 

 

HibernateTreeTest：

package com.bjsxt.hibernate;

import java.util.Map;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;

public class HibernateTreeTest {
 private static SessionFactory sessionFactory;
 
 @BeforeClass
 public static void beforeClass() {
  new SchemaExport(new AnnotationConfiguration().configure()).create(false, true);
  sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();
 }
 @AfterClass
 public static void afterClass() {
  sessionFactory.close();
 }
 
 @Test
 public void testSave() {
  Org o = new Org();
  o.setName("总公司");
  Org o1 = new Org();
  o1.setName("分公司1");
  Org o2 = new Org();
  o2.setName("分公司2");
  Org o11 = new Org();
  o11.setName("分公司1下部门1");
  Org o12 = new Org();
  o12.setName("分公司1下部门2");
  
  o.getChildren().add(o1);
  o.getChildren().add(o2);
  o1.getChildren().add(o11);
  o1.getChildren().add(o12);
  o11.setParent(o1);
  o12.setParent(o1);
  o1.setParent(o);
  o2.setParent(o);
    
  
  Session session = sessionFactory.openSession();
  session.beginTransaction();
  session.save(o);
 
  session.getTransaction().commit();
  session.close();
 }
 
 @Test
 public void testLoad() {
  testSave();
  Session session = sessionFactory.openSession();
  session.beginTransaction();
  Org o = (Org)session.load(Org.class, 1);
  print(o, 0);
  session.getTransaction().commit();
  session.close();
  
 }
 
 private void print(Org o, int level) {
      String preStr = "";
      for(int i=0; i<level; i++) {
           preStr += "----";
      }
     System.out.println(preStr + o.getName());
     for(Org child : o.getChildren()) {
          print(child, level+1);
     }
 }

 @Test
 public void testSchemaExport() {
  new SchemaExport(new AnnotationConfiguration().configure()).create(false, true);
 }
 
 
 public static void main(String[] args) {
  beforeClass();
 }
}