1 package com.hfut.hibernate; 2  3 import java.util.HashSet; 4 import java.util.Set; 5  6 import javax.persistence.CascadeType; 7 import javax.persistence.Entity; 8 import javax.persistence.FetchType; 9 import javax.persistence.GeneratedValue;10 import javax.persistence.Id;11 import javax.persistence.JoinColumn;12 import javax.persistence.ManyToOne;13 import javax.persistence.OneToMany;14 15 @Entity16 public class Node {    17     private int id;18     private String name;19     private Node parent;20     private Set<Node> children = new HashSet<Node>();21 22     @Id23     @GeneratedValue24     public int getId() {25         return id;26     }27     public void setId(int id) {28         this.id = id;29     }30     public String getName() {31         return name;32     }33     public void setName(String name) {34         this.name = name;35     }36     @ManyToOne(cascade=CascadeType.ALL)37     @JoinColumn(name="nodeId")38     public Node getParent() {39         return parent;40     }41     public void setParent(Node parent) {42         this.parent = parent;43     }44     @OneToMany(mappedBy="parent", cascade=CascadeType.ALL,fetch=FetchType.EAGER)45     public Set<Node> getChildren() {46         return children;47     }48     public void setChildren(Set<Node> children) {49         this.children = children;50     }51 }

 1 <?xml version=‘1.0‘ encoding=‘utf-8‘?> 2 <!DOCTYPE hibernate-configuration PUBLIC 3         "-//Hibernate/Hibernate Configuration DTD 3.0//EN" 4         "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> 5  6 <hibernate-configuration> 7  8     <session-factory> 9 10          11         <property name="connection.driver_class">com.mysql.jdbc.Driver</property>12         <property name="connection.url">jdbc:mysql://localhost/testone</property>13         <property name="connection.username">root</property>14         <property name="connection.password">123456</property>15         <property name="dialect">org.hibernate.dialect.MySQLDialect</property>16        <!--17         <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>18         <property name="connection.url">jdbc:oracle:thin:@localhost:1521:SXT</property>19         <property name="connection.username">scott</property>20         <property name="connection.password">tiger</property>21           <property name="dialect">org.hibernate.dialect.OracleDialect</property>22        -->23 24         <!-- JDBC connection pool (use the built-in) -->25         <property name="connection.pool_size">1</property>26 27         28 29         <!-- Enable Hibernate‘s automatic session context management -->30         <property name="current_session_context_class">thread</property>31 32         <!-- Disable the second-level cache  -->33         <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>34 35         <!-- Echo all executed SQL to stdout -->36         <property name="show_sql">true</property>37         <property name="format_sql">true</property>38 39         <!-- Drop and re-create the database schema on startup40         <property name="hbm2ddl.auto">update</property>41          -->42     <mapping class="com.hfut.hibernate.Node"/>43 44     </session-factory>45 46 </hibernate-configuration>

 1 package com.hfut.hibernate; 2  3 import org.hibernate.Session; 4 import org.hibernate.SessionFactory; 5 import org.hibernate.cfg.AnnotationConfiguration; 6 import org.hibernate.tool.hbm2ddl.SchemaExport; 7 import org.junit.AfterClass; 8 import org.junit.BeforeClass; 9 import org.junit.Test;10 11 import com.hfut.hibernate.TreeNode;12 13 public class TreeNodeTest {14     15     private static SessionFactory sessionFactory;16     17     @BeforeClass18     public static void beforeClass() {19         new SchemaExport(new AnnotationConfiguration().configure()).create(false, true);20         sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();21     }22     23     @AfterClass24     public static void afterClass() {25         sessionFactory.close();26     }27 28     public void testSave() {29         Session session = sessionFactory.openSession();30         TreeNode node0 = new TreeNode();31         node0.setName("父亲");32         TreeNode node1 = new TreeNode();33         node1.setName("大儿子");34         TreeNode node2 = new TreeNode();35         node2.setName("小儿子");36         TreeNode node3 = new TreeNode();37         node3.setName("大儿子的大儿子");38         TreeNode node4 = new TreeNode();39         node4.setName("大儿子的小儿子");40         TreeNode node5 = new TreeNode();41         node5.setName("小儿子的大儿子");42         TreeNode node6 = new TreeNode();43         node6.setName("小儿子的小儿子");44         45         node0.getChildren().add(node1);46         node0.getChildren().add(node2);47         node1.getChildren().add(node3);48         node1.getChildren().add(node4);49         node1.setParent(node0);50         node2.getChildren().add(node5);51         node2.getChildren().add(node6);52         node2.setParent(node0);53         node3.setParent(node1);54         node4.setParent(node1);55         node5.setParent(node2);56         node6.setParent(node2);57         58         session.beginTransaction();59         session.save(node0);60         session.getTransaction().commit();61         session.close();62     }63     @Test64     public void testLoad() {65         testSave();66         Session session = sessionFactory.openSession();67         session.beginTransaction();68         TreeNode node = (TreeNode)session.load(TreeNode.class, 1);69         print(node,0);70         session.getTransaction().commit();71         session.close();72     }73 74     private void print(TreeNode node,int level) {75         String preStr = "";76         for(int i=0;i<level;i++){77             preStr +="----";78         }79         System.out.println(preStr+node.getName());80         for(TreeNode children:node.getChildren()){81             print(children,level+1);82         }    83     }84 }