vpptransactionwrapper.java

这是一个用java和xml编写的流媒体服务器管理软件

/*
 * ====================================================================
 * The Vovida Software License, Version 1.0
 * 
 * Copyright (c) 2000 Vovida Networks, Inc.  All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in
 * the documentation and/or other materials provided with the
 * distribution.
 * 
 * 3. The names "VOCAL", "Vovida Open Communication Application Library",
 * and "Vovida Open Communication Application Library (VOCAL)" must
 * not be used to endorse or promote products derived from this
 * software without prior written permission. For written
 * permission, please contact [e-mail].
 * 
 * 4. Products derived from this software may not be called "VOCAL", nor
 * may "VOCAL" appear in their name, without prior written
 * permission of Vovida Networks, Inc.
 * 
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND
 * NON-INFRINGEMENT ARE DISCLAIMED.  IN NO EVENT SHALL VOVIDA
 * NETWORKS, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT DAMAGES
 * IN EXCESS OF $1,000, NOR FOR ANY INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 * 
 * ====================================================================
 * 
 * This software consists of voluntary contributions made by Vovida
 * Networks, Inc. and many individuals on behalf of Vovida Networks,
 * Inc.  For more information on Vovida Networks, Inc., please see
 * <http://www.vovida.org/>.
 * 
 */
package vocal.comm;

import java.io.IOException;
import java.io.FileNotFoundException;
import java.io.BufferedReader;
import java.io.StringReader;

import java.net.ConnectException;

import javax.swing.*;

/**
 * This class provides GUI-friendly versions of the public methods of
 * VPPTransaction, catching exceptions they throw and displaying
 * them in dialog boxes.
 */
public class VPPTransactionWrapper
{
  VPPTransaction wrappee;

  public VPPTransactionWrapper(String server, int port) throws VPPException
  {

    // will throw a VPPLowLevelException if it cannot connect
    // properly to the server
    wrappee = new VPPTransaction(server, port);
  }

  /**
   * Requests authorization from the server.
   * Authorization must be granted before the server will
   * honor other requests from this connection.
   * @param username login id
   * @param password password to authenticate for this login id
   * @return true if authentication granted
   */
   public int authenticate(String username, String password)
     throws VPPException
   {
     return wrappee.doAuth(username, password);
   }

  /**
   * Sends a GET request to the server. <p>
   * @param group string giving the path to the file to get.
   * @param filename name of the file, must include extension
   * @return a string containing the respone
   * throws VPPNoSuchFileException on error (which may not be an error
   * if this is being used to check for the existence of the file) or
   * some other VPP error (such as malformed header). Be sure to check
   * that the error is a NoSuchFileException if you are using this to
   * check for the existence of a file
   */
  public String doGet(String group, String filename) throws VPPException
  {
    String stringToReturn = "";

    stringToReturn = wrappee.doGet(group, filename);

    return stringToReturn;
  }


  /**
   * Sends a request to delete an item from the server. <p>
   * 
   */
  public void doDel(String group, String item) throws VPPException
  {
    wrappee.doDel(group, item);
  }


  /**
   * Perform the "PUT" operation.
   * @param group the destination of the data
   * @param filename name of the file holding the data. Must include
   * extension.
   * @param entityToPut the data to PUT.
   * @exception VPPException on failure
   */
  public void doPut(String group, String filename, 
                    String entityToPut) throws VPPException
  {
    wrappee.doPut(group, filename, entityToPut);
  }

  public void doSubPut(String group, String filename, 
          String entityToPut) throws VPPException
  {
	  wrappee.doSubPut(group, filename, entityToPut);
  }
  /**
   * Perform the "PUT" operation.
   * @param group the destination of the data
   * @param filename name of the file holding the data. Must include
   * extension.
   * @param entityToPut the data to PUT.
   * @param destination flag to determine if one should put to the
   * server or to a file. The options are WRITE_TO_FILE or WRITE_TO_PSERVER
   * @exception VPPException on failure
   */
  public void doPut(String group, String filename, String entityToPut, 
                    int destination) throws VPPException
  {
    wrappee.doPut(group, filename, entityToPut, destination);
  }


  /**
   * A more generic request method which returns the response wrapped in a
   * BufferedReader instead of a string.
   * @param type string which specifies the type of request to perform (Eg,
   * GET, DELETE.
   * @param arg1 first argument to the request type (Eg, group)
   * @param arg2 second argument to the request type (Eg, filename)
   * If the user sends a GET they may get VPPNoSuchFileException,
   * else, they may get VPPPermissionException. As always, may throw
   * other VPP errors for error conditions. IOException can be thrown
   * if there is a problem with the BufferedReader
   */
  public BufferedReader request(String type, String arg1, 
          String arg2) throws VPPException
  {
    BufferedReader response = null;

    response = wrappee.request(type, arg1, arg2);

    return response;
  }

  /**
   * A request that will be sent through exactly as is.
   * @return the response as a String
   */
  public String request(String type, String requestString) throws VPPException
  {
    String response = null;

    response = wrappee.sendRequest(type, requestString, "");

    return response;
  }


  public String requestString(String type, String arg1, 
          String arg2) throws VPPException
  {
    String response = null;

    response = wrappee.requestString(type, arg1, arg1);

    return response;
  }


  /**
   * Displays a dialog which shows the text of an exception.
   */
  public static void showException(Exception exception, String message)
  {

    StringBuffer explanation = new StringBuffer(message);

    explanation.append("\n\n");

    if (exception instanceof VPPException)
    {
      explanation.append("There was a problem communicating with" 
                         + "the pServer.\n\nThe Output was:\n\n");
    }
    else if (exception instanceof IOException)
    {
      explanation.append("There was an input/output problem.\n\n" 
                         + "Please try your operation again.\n\n" 
                         + "Here is the exception thrown:\n\n");
    }

    explanation.append(exception.getMessage());

    JFrame frame = new JFrame();

    JOptionPane.showMessageDialog(frame, explanation.toString(), "Error", 
            JOptionPane.ERROR_MESSAGE);
  }


  /**
   * Displays a dialog which shows the text of an exception, but handles
   * the various VPP cases more specifically.
   */
  public static void showVPPException(VPPException exception, String message)
  {

    StringBuffer explanation = new StringBuffer(message);

    explanation.append("\n\n");

    if (exception instanceof VPPLowLevelException)
    {
      explanation.append("A low level failure occured while " 
                         + "communicating with the pServer.\n\n" 
                         + "The exception thrown was: \n\n");
    }
    else if (exception instanceof VPPMalformedMsgException)
    {
      explanation.append("The transaction failed due to " 
                         + "malformed messages being passed\n" 
                         + "between the client and server.\n\n" 
                         + "The problem reported was was: \n\n");
    }
    else if (exception instanceof VPPNoConnException)
    {
      explanation.append("The transaction failed because " 
                         + "the GUI is not connected to the server." + "\n\n" 
                         + "The problem reported was was: \n\n");
    }
    else if (exception instanceof VPPNoSuchFileException)
    {
      explanation.append("The transaction failed because " 
                         + "the requested file could not be found " 
                         + "or read.\n\n" 
                         + "The problem reported was was: \n\n");
    }
    else if (exception instanceof VPPAuthException)
    {
      explanation.append("The transaction failed because " 
                         + "permission was denied. Even if the\n" 
                         + "write shows on the server, it likely " 
                         + "did not make it to the server.\n\n" 
                         + "The problem reported was was: \n\n");
    }
    else if (exception instanceof VPPPermissionException)
    {
      explanation.append("Authorization Failed\n\n");
    }

    explanation.append(exception.getMessage());

    JFrame frame = new JFrame();

    JOptionPane.showMessageDialog(frame, explanation.toString(), "Error", 
            JOptionPane.ERROR_MESSAGE);
  }



  /**
   * Close the streams and socket for the underlying VPPTransaction
   * once you are finished using the connection.
   * Can throw a low level exception.
   */
  public void close() throws VPPException
  {
    wrappee.close();
  }

}