libjava/java/io/PipedWriter.java

   1 // PipedWriter.java - Piped character stream.
   2
   3 /* Copyright (C) 1998, 1999  Cygnus Solutions
   4
   5    This file is part of libgcj.
   6
   7 This software is copyrighted work licensed under the terms of the
   8 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
   9 details.  */
  10
  11 package java.io;
  12
  13 /**
  14  * @author Tom Tromey <tromey@cygnus.com>
  15  * @date September 25, 1998
  16  */
  17
  18 /* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
  19  * "The Java Language Specification", ISBN 0-201-63451-1
  20  * Status:  Complete to 1.1.
  21  */
  22
  23 public class PipedWriter extends Writer
  24 {
  25   public void close () throws IOException
  26   {
  27     closed = true;
  28   }
  29
  30   public void connect (PipedReader sink) throws IOException
  31   {
  32     if (closed)
  33       throw new IOException ("already closed");
  34     if (reader != null)
  35       {
  36         if (reader == sink)
  37           return;
  38         throw new IOException ("already connected");
  39       }
  40     try
  41       {
  42         reader = sink;
  43         reader.connect(this);
  44       }
  45     catch (IOException e)
  46       {
  47         reader = null;
  48         throw e;
  49       }
  50   }
  51
  52   public void flush () throws IOException
  53   {
  54     // We'll throw an exception if we're closed, but there's nothing
  55     // else to do here.
  56     if (closed)
  57       throw new IOException ("closed");
  58   }
  59
  60   public PipedWriter ()
  61   {
  62     super ();
  63     closed = false;
  64   }
  65
  66   public PipedWriter (PipedReader sink) throws IOException
  67   {
  68     super ();
  69     closed = false;
  70     connect (sink);
  71   }
  72
  73   public void write (char buffer[], int offset, int count) throws IOException
  74   {
  75     if (closed)
  76       throw new IOException ("closed");
  77     reader.receive(buffer, offset, count);
  78   }
  79
  80   boolean isClosed ()
  81   {
  82     return closed;
  83   }
  84
  85   // The associated reader.
  86   private PipedReader reader;
  87   private boolean closed;
  88 }