/*

  * Copyright 2007 the original author or authors.

  * 

  * Licensed under the Apache License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  * 

  *      http://www.apache.org/licenses/LICENSE-2.0

  * 

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.mockftpserver.stub.command;

 import org.mockftpserver.core.MockFtpServerException;

 import org.mockftpserver.core.command.Command;

 import org.mockftpserver.core.command.CommandHandler;

 import org.mockftpserver.core.command.InvocationRecord;

 import org.mockftpserver.core.session.Session;

 import org.mockftpserver.core.util.Assert;

 import org.mockftpserver.core.util.AssertFailedException;

 import java.io.IOException;

 import java.io.InputStream;

 /**

  * CommandHandler for the RETR command. Returns the contents of the specified file on the

  * data connection, along with two replies on the control connection: a reply code of 150 and

  * another of 226.

  * <p/>

  * The <code>file</code> property specifies the pathname for the file whose contents should

  * be returned from this command. The file path is relative to the CLASSPATH (using the

  * ClassLoader for this class).

  * <p/>

  * An exception is thrown if the <code>file</code> property has not been set or if the specified

  * file does not exist or cannot be read.

  * <p/>

  * Each invocation record stored by this CommandHandler includes the following data element key/values:

  * <ul>

  * <li>{@link #PATHNAME_KEY} ("pathname") - the pathname of the file submitted on the invocation (the first command parameter)

  * </ul>

  *

  * @author Chris Mair

  * @version $Revision: 194 $ - $Date: 2008-12-07 08:53:58 -0500 (Sun, 07 Dec 2008) $

  */

 public class FileRetrCommandHandler extends AbstractStubDataCommandHandler implements CommandHandler {

     public static final String PATHNAME_KEY = "pathname";

     static final int BUFFER_SIZE = 512;     // package-private for testing

     private String file;

     /**

      * Create new uninitialized instance

      */

     public FileRetrCommandHandler() {

     }

     /**

      * Create new instance using the specified file pathname

      *

      * @param file - the path to the file

      * @throws AssertFailedException - if the file is null

      */

     public FileRetrCommandHandler(String file) {

         setFile(file);

     }

     /**

      * @see org.mockftpserver.stub.command.AbstractStubDataCommandHandler#beforeProcessData(org.mockftpserver.core.command.Command, org.mockftpserver.core.session.Session, org.mockftpserver.core.command.InvocationRecord)

      */

     protected void beforeProcessData(Command command, Session session, InvocationRecord invocationRecord) throws Exception {

         Assert.notNull(file, "file");

         invocationRecord.set(PATHNAME_KEY, command.getRequiredParameter(0));

     }

     /**

      * @see org.mockftpserver.stub.command.AbstractStubDataCommandHandler#processData(org.mockftpserver.core.command.Command, org.mockftpserver.core.session.Session, org.mockftpserver.core.command.InvocationRecord)

      */

     protected void processData(Command command, Session session, InvocationRecord invocationRecord) {

         InputStream inputStream = getClass().getClassLoader().getResourceAsStream(file);

         Assert.notNull(inputStream, "InputStream for [" + file + "]");

         byte[] buffer = new byte[BUFFER_SIZE];

         try {

             int numBytes;

             while ((numBytes = inputStream.read(buffer)) != -1) {

                 LOG.trace("Sending " + numBytes + " bytes...");

                 session.sendData(buffer, numBytes);

             }

         }

         catch (IOException e) {

             throw new MockFtpServerException(e);

         }

     }

     /**

      * Set the path of the file whose contents should be returned when this command is

      * invoked. The path is relative to the CLASSPATH.

      *

      * @param file - the path to the file

      * @throws AssertFailedException - if the file is null

      */

     public void setFile(String file) {

         Assert.notNull(file, "file");

         this.file = file;

     }

 }