hibernate 树状映射

package com.bjsxt.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")
    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;
    }
}

 

 

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();
    }
}