pmacs3/code_examples/HibernateUtil.java

/////////////////////////////////////////////////////////////////////////
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("       ");
        }
    }
}