Java/Hibernate/Object Version
Record Object Version
<source lang="java">
///////////////////////////////////////////////////////////////////////// import java.io.Serializable; import java.util.*; import java.sql.*; 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 vmodule(id int,version int,name varchar,owner varchar);"); Session session = HibernateUtil.currentSession(); VersionModule mod = new VersionModule(); mod.setId(1); mod.setOwner("J"); mod.setName("M1"); System.out.println(mod.getVersion()); session.save(mod); session.flush(); HibernateUtil.closeSession();
session = HibernateUtil.currentSession(); mod.setOwner("J2"); session.saveOrUpdate(mod); session.flush(); System.out.println(mod.getVersion()); session.close(); HibernateUtil.checkData("select * from vmodule"); }
}
/////////////////////////////////////////////////////////////////////////
<?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="VersionModule" table="vmodule"> <id name="id" type="int"> <generator class="increment"/> </id> <version name="version" column="version" type="integer" unsaved-value="undefined"/> <property name="name"/> <property name="owner"/> </class>
</hibernate-mapping>
/////////////////////////////////////////////////////////////////////////
public class VersionModule {
public int id; private String name; private String owner; private int version; public void setId(int i) { id = i; } public int getId() { return id; } public void setName(String s) { name = s; } public String getName() { return name; } public void setOwner(String s) { owner = s; } public String getOwner() { return owner; } public void setVersion(int i) { version = i; } public int getVersion() { return version; }
}
/////////////////////////////////////////////////////////////////////////
<?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="VersionModule.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(" "); } }
}
/////////////////////////////////////////////////////////////////////////
</source>