package org.jscsi.target.connection.phase;

 import java.io.IOException;

 import java.security.DigestException;

 import javax.naming.OperationNotSupportedException;

 import org.jscsi.exception.InternetSCSIException;

 import org.jscsi.parser.ProtocolDataUnit;

 import org.jscsi.target.connection.Connection;

 import org.jscsi.target.settings.SettingsException;

 /**

  * Instances of this class represent a connection's phase (see {@link Connection} for a description of the relationship

  * between stages, phases, connections, and sessions).

  * <p>

  * To start a phase, one of the <i>execute</i> methods must be called, which one is sub-class-specific.

  * 

  * @author Andreas Ergenzinger, University of Konstanz

  */

 public abstract class TargetPhase {

     /**

      * The connection this phase is a part of.

      */

     protected Connection connection;

     /**

      * The abstract constructor.

      * 

      * @param connection the connection is phase is a part of

      */

     public TargetPhase (Connection connection) {

         this.connection = connection;

     }

     /**

      * Throws an {@link OperationNotSupportedException} unless overwritten.

      * 

      * @param pdu the first PDU to be processes as part of the phase

      * @return <code>true</code> if and only if the phase was completed successfully

      * @throws OperationNotSupportedException if the method is not overwritten

      * @throws IOException if an I/O error occurs

      * @throws InterruptedException if the current Thread is interrupted

      * @throws InternetSCSIException if a iSCSI protocol violation is detected

      * @throws DigestException if a PDU digest error is detected

      * @throws SettingsException if the target tries to access a parameter that has not been declared or negotiated and

      *             that has no default value

      */

     public boolean execute (ProtocolDataUnit pdu) throws OperationNotSupportedException , IOException , InterruptedException , InternetSCSIException , DigestException , SettingsException {

         throw new OperationNotSupportedException();

     }

     /**

      * Throws an {@link OperationNotSupportedException} unless overwritten.

      * 

      * @return <code>true</code> if and only if the phase was completed successfully

      * @throws OperationNotSupportedException if the method is not overwritten

      * @throws IOException if an I/O error occurs

      * @throws InterruptedException if the current Thread is interrupted

      * @throws InternetSCSIException if a iSCSI protocol violation is detected

      * @throws DigestException if a PDU digest error is detected

      * @throws SettingsException if the target tries to access a parameter that has not been declared or negotiated and

      *             that has no default value

      * @throws InitiatorLoginRequestException

      */

     public boolean execute () throws OperationNotSupportedException , InternetSCSIException , DigestException , IOException , InterruptedException , SettingsException {

         throw new OperationNotSupportedException();

     }

     /**

      * Getting the related connection

      * 

      * @return the connection

      */

     public Connection getTargetConnection () {

         return connection;

     }

 }