splitterline.java

结构非常清晰的SIP协议栈

/*
 * Copyright (C) 2005 Luca Veltri - University of Parma - Italy
 * 
 * This source code is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This source code 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this source code; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 * 
 * Author(s):
 * Luca Veltri ([e-mail])
 */

package local.media;


import java.io.*;
import java.util.Hashtable;
import java.util.Enumeration;


/** SplitterLine is a simple splitter with one input line (the SplitterLine itself)
  * and N output lines (OutputStreams). 
  * <p/>
  * Each output line has an identifier (Object) used as key when adding or
  * removing the line. 
  */
public class SplitterLine extends OutputStream
{
   /** SplitterLine identifier. */
   Object splitter_id;

   /** The output lines (as Hashtable of Object->OutputStream). */
   Hashtable output_lines;
 
   
   /** Creates a new SplitterLine. */
   public SplitterLine(Object splitter_id)
   {  this.splitter_id=splitter_id;
      output_lines=new Hashtable();
   }

   /** Creates a new SplitterLine. */
   public SplitterLine(Object splitter_id, Hashtable output_lines)
   {  this.splitter_id=splitter_id;
      this.output_lines=output_lines;
   }


   /** Adds a new line. */
   public void addLine(Object id, OutputStream os)
   {  //System.err.println("SL: add: "+id+" "+os);
      output_lines.put(id,os);
   }

   /** Removes a line. */
   public void removeLine(Object id)
   {  //System.err.println("SL: remove: "+id);
      output_lines.remove(id);
   }


   /** Closes this output stream and releases any system resources associated with this stream. */
   public void close() throws IOException
   {  for (Enumeration e=output_lines.elements(); e.hasMoreElements(); )
      {  ((OutputStream)e.nextElement()).close();
      }
      output_lines=null;
   }
   
   /** Flushes this output stream and forces any buffered output bytes to be written out. */
   public void flush() throws IOException
   {  for (Enumeration e=output_lines.elements(); e.hasMoreElements(); )
      {  ((OutputStream)e.nextElement()).flush();
      }
   }
   
   /** Writes b.length bytes from the specified byte array to this output stream. */
   public void write(byte[] b) throws IOException
   {  //System.err.print("*");
      super.write(b);
      //System.err.print("@");
   }
   
   /** Writes len bytes from the specified byte array starting at offset off to this output stream. */
   public void write(byte[] b, int off, int len) throws IOException
   {  //System.err.print("*");
      super.write(b,off,len);
      //System.err.print("@");
   }
   
   /** Writes the specified byte to this output stream. */
   public void write(int b) throws IOException
   {  /*for (Enumeration e=output_lines.elements(); e.hasMoreElements(); )
      {  ((OutputStream)e.nextElement()).write(b);
      }*/
      for (Enumeration e=output_lines.keys(); e.hasMoreElements(); )
      {  Object line_id=e.nextElement();
         try
         {  ((OutputStream)output_lines.get(line_id)).write(b);
         }
         catch (IOException ex)
         {  System.err.println("SL("+splitter_id+"): ERROR while writing on line "+line_id);
            ex.printStackTrace();
            throw new IOException("SplitterLine error");
         }
      }
   }

}