Java/Hibernate/Map List

Hibernate Collection Mapping List

   <source lang="java">

///////////////////////////////////////////////////////////////////////// <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE hibernate-mapping

   PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN" 
   "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">

<hibernate-mapping>

   <class name="Group" table="grouptable">
        <id name="id" unsaved-value="0">
           <generator class="increment"/>
       </id>
       
       <list name="stories" cascade="all">
           <key column="parent_id"/>
           <index column="idx"/>
           <one-to-many class="Story"/>
       </list>
       <property name="name" type="string"/>
   </class>
   <class name="Story" 
        table="story">
        <id name="id" unsaved-value="0">
           <generator class="increment"/>
       </id>
         <property name="info"/>
   </class>

</hibernate-mapping>

///////////////////////////////////////////////////////////////////////// import java.util.*; public class Group {

 private int id;
 private String name;
 private List stories;
 public Group(){
 }
 public Group(String name) {
   this.name = name;
 }
 public void setId(int i) {
   id = i;
 }
 public int getId() {
   return id;
 }
 public void setName(String n) {
   name = n;
 }
 public String getName() {
   return name;
 }
 public void setStories(List l) {
   stories = l;
 }
 public List getStories() {
   return stories;
 }

}

///////////////////////////////////////////////////////////////////////// <?xml version="1.0" encoding="utf-8"?> <!DOCTYPE hibernate-configuration PUBLIC

   "-//Hibernate/Hibernate Configuration DTD//EN"
   "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

   <session-factory>
       
       <property name="connection.driver_class">org.hsqldb.jdbcDriver</property>
       <property name="connection.url">jdbc:hsqldb:data/tutorial</property>
       <property name="connection.username">sa</property>
       <property name="connection.password"></property>
       
       <property name="connection.pool_size">1</property>
       
       <property name="dialect">org.hibernate.dialect.HSQLDialect</property>
       
       <property name="show_sql">true</property>
       
       <mapping resource="Group.hbm.xml"/>
   </session-factory>

</hibernate-configuration>

///////////////////////////////////////////////////////////////////////// import java.sql.Connection; import java.sql.DriverManager; import java.sql.Statement; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import org.hibernate.HibernateException; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; public class HibernateUtil {

   public static final SessionFactory sessionFactory;
   static {
       try {
           // Create the SessionFactory from hibernate.cfg.xml
           sessionFactory = new Configuration().configure().buildSessionFactory();
       } catch (Throwable ex) {
           // Make sure you log the exception, as it might be swallowed
           System.err.println("Initial SessionFactory creation failed." + ex);
           throw new ExceptionInInitializerError(ex);
       }
   }
   public static final ThreadLocal session = new ThreadLocal();
   public static Session currentSession() throws HibernateException {
       Session s = (Session) session.get();
       // Open a new Session, if this thread has none yet
       if (s == null) {
           s = sessionFactory.openSession();
           // Store it in the ThreadLocal variable
           session.set(s);
       }
       return s;
   }
   public static void closeSession() throws HibernateException {
       Session s = (Session) session.get();
       if (s != null)
           s.close();
       session.set(null);
   }
   
   static Connection conn; 
   static Statement st;
 public static void setup(String sql) {
   try {
     // Step 1: Load the JDBC driver.
     Class.forName("org.hsqldb.jdbcDriver");
     System.out.println("Driver Loaded.");
     // Step 2: Establish the connection to the database.
     String url = "jdbc:hsqldb:data/tutorial";
     conn = DriverManager.getConnection(url, "sa", "");
     System.out.println("Got Connection.");
     st = conn.createStatement();
     st.executeUpdate(sql);
   } catch (Exception e) {
     System.err.println("Got an exception! ");
     e.printStackTrace();
     System.exit(0);
   }
 }
 public static void checkData(String sql) {
   try {
     HibernateUtil.outputResultSet(st
         .executeQuery(sql));

// conn.close();

   } catch (Exception e) {
     e.printStackTrace();
   }
 }
   public static void outputResultSet(ResultSet rs) throws Exception{
   ResultSetMetaData metadata = rs.getMetaData();
   int numcols = metadata.getColumnCount();
   String[] labels = new String[numcols]; 
   int[] colwidths = new int[numcols];
   int[] colpos = new int[numcols];
   int linewidth;
     for (int i = 0; i < numcols; i++) {
       labels[i] = metadata.getColumnLabel(i + 1); // get its label
       System.out.print(labels[i]+"  ");
   }
     System.out.println("------------------------");
   while (rs.next()) {
       for (int i = 0; i < numcols; i++) {
       Object value = rs.getObject(i + 1);
       if(value == null){
           System.out.print("       ");
       }else{
           System.out.print(value.toString().trim()+"   ");
       }
       
     }
       System.out.println("       ");
   }
   }

} /////////////////////////////////////////////////////////////////////////

log4j.rootCategory=WARN, console log4j.appender.console=org.apache.log4j.ConsoleAppender log4j.appender.console.layout=org.apache.log4j.PatternLayout log4j.appender.console.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n log4j.appender.stdout.Target=System.out

///////////////////////////////////////////////////////////////////////// import java.io.Serializable; import java.util.*; import org.hibernate.*; import org.hibernate.cfg.*; import org.hibernate.criterion.*; import org.hibernate.event.*; import org.hibernate.event.def.*; public class Main {

  public static void main(String[] args) throws Exception {
     HibernateUtil.setup("create table grouptable (id int,name varchar);");    
     HibernateUtil.setup("create table story (id int,info varchar,idx int,parent_id int);");    
     Session session = HibernateUtil.currentSession();
     Group sp = new Group("Group Name");
    
     ArrayList list = new ArrayList();
     list.add(new Story("Story Name 1"));
     list.add(new Story("Story Name 2"));
     sp.setStories(list);
     Transaction transaction = null;
     try {
          transaction = session.beginTransaction();
          session.save(sp);
          transaction.rumit();
     } catch (Exception e) { 
          if (transaction != null) {
            transaction.rollback();
            throw e;
          }
     }  finally { 
          session.close();
     }
     HibernateUtil.checkData("select * from grouptable");
     HibernateUtil.checkData("select * from story");      
  }

}

///////////////////////////////////////////////////////////////////////// import java.util.*; public class Story {

 private int id;
 private String info;
 public Story(){
 }
 public Story(String info) {
   this.info = info;
 }
 public void setId(int i) {
   id = i;
 }
 public int getId() {
   return id;
 }
 public void setInfo(String n) {
   info = n;
 }
 public String getInfo() {
   return info;
 }

}

      </source>