jtsessionfacadeejb.java

来自「Java Pattern Oriented Framework (Jt) 是为了」· Java 代码 · 共 403 行

package Jt.ejb;

import javax.ejb.*;
import java.util.*;
import Jt.*;


/**
 * Jt implementation of the J2EE Session Facade pattern.
 * Provides an EJB interface to the Jt API. This bean is invoked by 
 * JtEJBAdapter and JtBusinessDelegate. By using JtEJBAdapter, J2EE 
 * clients are able to transparently manipulate remote Jt objects. 
 *
 * @ejb:bean type="Stateful"
 *     name="JtSessionFacade"
 *     jndi-name="JtSessionFacade"
 *     display-name="Jt Session Facade"
 */

public class JtSessionFacadeEJB implements SessionBean {

    private static final long serialVersionUID = 1L;
    private Hashtable sessionTable  = new Hashtable ();
    private JtFactory factory;


    // Implement the methods in the SessionBean interface


    public void ejbActivate()  {  
    }

    public void ejbRemove() {

    }

    public void ejbPassivate() {

    }

    /**
     * Sets the session context.
     *
     * @param ctx  session context
     */

    public void setSessionContext(SessionContext ctx) 
    throws javax.ejb.EJBException, java.rmi.RemoteException 
    {
    }



    public void ejbCreate () {

    }


    private String calculateSessionID (Object shadow) {

        String sessionID;


        // The following should provide an unique session ID.
        // It is highly unlikely that two clients will have the same sessionid 
        // If needed, A stronger mechanism may be used
        // This method is being deprecated.

        for (;;) {
            sessionID = "JtSESSION" + shadow + (new Date()).getTime();  

            if (sessionTable.get (sessionID) == null)
                break;

        }

        return (sessionID);  

    }

    /**
     * Creates an independent session. Each client session is able to manipulate 
     * Jt objects without interfering with each other. Each session is assigned an 
     * unique session ID. This method is being deprecated.
     * 
     *
     * @ejb.interface-method
     */


    public Object createSession ()
    throws JtException  
    {

        JtObject shadow;
        Object session;


        shadow = new JtObject ();
        session = calculateSessionID (shadow);
        sessionTable.put (session, shadow);

        shadow.handleTrace ("JtSessionFacadeEJB.createSession:session:" + session);
        return (session);
    }


    /**
     * Removes a session (being deprecated)
     *
     * @ejb.interface-method
     */


    public void removeSession (Object session)
    throws JtException  
    {
        JtObject shadow;

        if (session == null)
            throw new JtException ("JtSessionFacadeEJB.removeSession:invalid session:" + session);


        shadow = (JtObject) sessionTable.get (session);

        if (shadow == null) {
            throw new JtException ("JtSessionFacadeEJB.removeSession:invalid session:" + session);
        }

        shadow.handleTrace ("JtSessionFacadeEJB.removeSession:session:" + session);
        sessionTable.remove (session);
    }

    /**
     * Creates a Jt object within the specified session
     *
     * @ejb.interface-method
     */


    public Object createObject (Object session, Object class_name, Object obj_id)
    throws JtException  
    {
        JtFactory shadow;
        Object output;
        Exception ex;

/*
        if (session == null)
            throw new JtException ("JtSessionFacadeEJB.createObject:invalid session:" + session);

        shadow = (JtObject) sessionTable.get (session);

        if (shadow == null) {
            throw new JtException ("JtSessionFacadeEJB.createObject:invalid session:" + session);
        }
*/
        
        if (factory == null) {
            factory = new JtFactory ();
            //factory.setLogging (true);
            //factory.setLogLevel(JtObject.JtMIN_LOG_LEVEL);
        }
        shadow = factory;
        
        //shadow.handleTrace ("JtSessionFacadeEJB.createObject:session:" + session);

        shadow.setObjException (null);

        output = shadow.createObject (class_name, obj_id);

        // Check for exceptions

        ex = (Exception) shadow.getObjException ();

        if (ex != null)
            throw new JtException (ex.getMessage ());

        if (output == null)
            return (null);
        return (output.toString());
    }

    /**
     * 	Removes an object
     *
     * @ejb.interface-method
     */

    public void removeObject (Object session, Object obj_id) 
    throws JtException  
    {

        JtFactory shadow;
        Exception ex;
/*
        if (session == null)
            throw new JtException ("JtSessionFacadeEJB.removeObject:invalid session:" + session); 

        shadow = (JtObject) sessionTable.get (session);

        if (shadow == null) {
            throw new JtException ("JtSessionFacadeEJB.removeObject:invalid session:" + session); 
        }

        shadow.handleTrace ("JtSessionFacadeEJB.removeObject:session:" + session);
*/        
        
        if (factory == null)
            factory = new JtFactory ();
        
        shadow = factory;

        shadow.setObjException (null);
        shadow.removeObject (obj_id);

        // Check for exceptions

        ex = (Exception) shadow.getObjException ();

        if (ex != null)
            throw new JtException (ex.getMessage ());
    }


    /**
     * Sends a message to an object
     *
     * @ejb.interface-method
     */ 


    public Object sendMessage (Object session, Object obj_id, Object msg_id) 
    throws JtException  

    {
        JtFactory shadow;
        Object output;
        Exception ex;


/*
        if (session == null)
            throw new JtException ("JtSessionFacadeEJB.sendMessage:invalid session:" + session);

        shadow = (JtObject) sessionTable.get (session);

        if (shadow == null) 
            throw new JtException ("JtSessionFacadeEJB.sendMessage:invalid session:" + session);
*/
        
        if (factory == null)
            factory = new JtFactory ();
        
        shadow = factory;       
        shadow.handleTrace ("JtSessionFacadeEJB.sendMessage:this:" + this);
        //shadow.handleTrace ("JtSessionFacadeEJB.sendMessage:session:" + session); 


        shadow.setObjException (null);
        output = shadow.sendMessage (obj_id, msg_id);

        // Check for exceptions

        ex = (Exception) shadow.getValue (obj_id, "objException");

        if (ex != null) {
            //shadow.handleException(ex);
            throw new JtException (ex.getMessage ());
        }
        ex = (Exception) shadow.getObjException ();

        if (ex != null) {
          //shadow.handleException(ex);            
          throw new JtException (ex.getMessage ());
        }  

        return (output);
    }


    /**
     * Gets the value of an attribute
     *
     * @ejb.interface-method
     */

    public Object getValue (Object session, Object obj_id, Object att) 
    throws JtException  
    {

        JtFactory shadow;
        Object output;
        Exception ex;


/*
        if (session == null)
            throw new JtException ("JtSessionFacadeEJB.getValue:invalid session:" + session);

        shadow = (JtObject) sessionTable.get (session);

        if (shadow == null)
            throw new JtException ("JtSessionFacadeEJB.getValue:invalid session:" + session);

        shadow.handleTrace ("JtSessionFacadeEJB.getValue:session:" + session);
*/        
        
        if (factory == null)
            factory = new JtFactory ();
        
        shadow = factory;    

        shadow.setObjException (null);

        output = shadow.getValue (obj_id, att);

        ex = (Exception) shadow.getObjException ();

        if (ex != null)
            throw new JtException (ex.getMessage ());


        return (output);
    }


    /**
     * Sets the value of an attribute
     * 
     * @ejb.interface-method
     */


    public void setValue (Object session, Object obj_id, Object att, Object value)
    throws JtException
    {

        JtFactory shadow;
        Exception ex;
/*
        if (session == null)
            throw new JtException ("JtSessionFacadeEJB.setValue:invalid session:" + session);

        shadow = (JtObject) sessionTable.get (session);

        if (shadow == null)
            throw new JtException ("JtSessionFacadeEJB.setValue:invalid session:" + session);
        
        shadow.handleTrace ("JtSessionFacadeEJB.setValue:session:" + session);
*/        
        
        if (factory == null)
            factory = new JtFactory ();
        
        shadow = factory;    

        shadow.setObjException (null);
        shadow.setValue (obj_id, att, value);

        ex = (Exception) shadow.getObjException ();

        if (ex != null)
            throw new JtException (ex.getMessage ());

    }  

    /**
     * Defines the log file (debugging purposes only)
     * @ejb.interface-method
     */

    public void setLogFile(Object session, String newLogFile) 
    throws JtException

    {

        JtObject shadow;


        if (session == null)
            throw new JtException ("JtSessionFacadeEJB.setLogFile:invalid session:" + session);

        shadow = (JtObject) sessionTable.get (session);

        if (shadow == null) {
            shadow = new JtObject ();

            sessionTable.put (session, shadow);
        }

        //shadow.handleTrace ("JtEJB.setLogFile:session:" + session);
        shadow.setLogFile (newLogFile);

    }


}