MLLPSocketCache.java

/*!
 * This program is free software; you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
 * Foundation.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
 * or from the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * Copyright (c) 2002-2013 Pentaho Corporation..  All rights reserved.
 */

package org.pentaho.di.trans.steps.hl7input.common;

import java.net.ServerSocket;
import java.util.HashMap;
import java.util.Map;

import org.pentaho.di.core.exception.KettleException;
import org.pentaho.di.job.Job;
import org.pentaho.di.job.JobAdapter;

import ca.uhn.hl7v2.protocol.StreamSource;
import ca.uhn.hl7v2.protocol.impl.MLLPTransport;
import ca.uhn.hl7v2.protocol.impl.ServerSocketStreamSource;

public class MLLPSocketCache {

  private static MLLPSocketCache cache;

  private Map<String, MLLPSocketCacheEntry> map;

  public static MLLPSocketCache getInstance() {
    if ( cache == null ) {
      cache = new MLLPSocketCache();
    }
    return cache;
  }

  public MLLPSocketCache() {
    map = new HashMap<String, MLLPSocketCacheEntry>();
  }

  public MLLPSocketCacheEntry getServerSocketStreamSource( String server, int port ) throws Exception {
    final String key = createKey( server, port );
    MLLPSocketCacheEntry s = map.get( key );
    if ( s != null ) {
      return s;
    }

    // Open the socket for this server/port combination.
    //
    ServerSocket serverSocket = new ServerSocket( port );
    StreamSource streamSource = new ServerSocketStreamSource( serverSocket, server );
    MLLPTransport transport = new MLLPTransport( streamSource );
    transport.connect();

    final MLLPSocketCacheEntry entry = new MLLPSocketCacheEntry( serverSocket, streamSource, transport );
    entry.setJobListener( new JobAdapter() {

      @Override
      public void jobFinished( Job job ) throws KettleException {
        KettleException exception = null;
        try {
          entry.getTransport().disconnect();
        } catch ( Exception e ) {
          exception = new KettleException( e );
        }
        try {
          entry.getStreamSource().disconnect();
        } catch ( Exception e ) {
          exception = new KettleException( e );
        }
        try {
          entry.getServerSocket().close();
        } catch ( Exception e ) {
          exception = new KettleException( e );
        }

        map.remove( key );

        if ( exception != null ) {
          throw exception;
        }
      }
    } );
    // Store a copy in our map to make sure that only the first return value contains the job listener.
    //
    map.put( key, new MLLPSocketCacheEntry( serverSocket, streamSource, transport ) );

    return entry;
  }

  private String createKey( String server, int port ) {
    return server + ":" + port;
  }
}