jtopenlite.com.ibm.jtopenlite.PortMapper Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of jt400 Show documentation
The Open Source version of the IBM Toolbox for Java
There is a newer version: 20.0.8
///////////////////////////////////////////////////////////////////////////////
//
// JTOpenLite
//
// Filename:  PortMapper.java
//
// The source code contained herein is licensed under the IBM Public License
// Version 1.0, which has been approved by the Open Source Initiative.
// Copyright (C) 2011-2012 International Business Machines Corporation and
// others.  All rights reserved.
//
///////////////////////////////////////////////////////////////////////////////

package com.ibm.jtopenlite;

import java.io.*;
import java.net.*;

/**
 * Connects to the System i Port Mapper host server (QSYSWRK/QZSOMAPD daemon job) listening on TCP port 449.
**/
public class PortMapper
{
  /**
   * Constant representing the System i Signon Host Server.
  **/
  public static final String SIGNON_SERVICE = "as-signon";

  /**
   * Constant representing the System i Remote Command Host Server.
  **/
  public static final String COMMAND_SERVICE = "as-rmtcmd";

  /**
   * Constant representing the System i DDM/DRDA Host Server.
  **/
  public static final String DDM_SERVICE = "drda"; //"as-ddm";

  /**
   * Constant representing the System i File Host Server.
  **/
  public static final String FILE_SERVICE = "as-file";

  /**
   * Constant representing the System i Database Host Server.
  **/
  public static final String DATABASE_SERVICE = "as-database";

  private PortMapper()
  {
  }

  /**
   * Issues a request to the Port Mapper host server on the specified system
   * to determine the TCP/IP port the specified service is listening on.
  **/
  public static int getPort(String system, String service) throws IOException
  {
    Socket portMapper = new Socket(system, 449);
    InputStream in = portMapper.getInputStream();
    OutputStream out = portMapper.getOutputStream();
    try
    {
      // Port mapper request.
      byte[] serviceName = service.getBytes("ISO_8859-1");
      out.write(serviceName);
      out.flush();

      // Unused variable
      // int portNum = -1;

      int i = in.read();
      if (i == 0x002B)
      {
        // unused variable
        // int num = 0;
        int b1 = in.read();
        if (b1 < 0) throw new EOFException();
        int b2 = in.read();
        if (b2 < 0) throw new EOFException();
        int b3 = in.read();
        if (b3 < 0) throw new EOFException();
        int b4 = in.read();
        if (b4 < 0) throw new EOFException();
        return ((b1 & 0x00FF) << 24) |
               ((b2 & 0x00FF) << 16) |
               ((b3 & 0x00FF) << 8) |
               (b4 & 0x00FF);
      }
      else
      {
        throw new IOException("Bad result from port mapper: "+i);
      }
    }
    finally
    {
      // The port mapper host server only handles one request per socket, apparently.
      in.close();
      out.close();
      portMapper.close();
    }
  }
}