| 1 | /* PipedWriter.java -- Write portion of piped character streams.
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| 2 | Copyright (C) 1998, 2000, 2001 Free Software Foundation, Inc.
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| 3 |
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| 4 | This file is part of GNU Classpath.
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| 5 |
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| 6 | GNU Classpath is free software; you can redistribute it and/or modify
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| 7 | it under the terms of the GNU General Public License as published by
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| 8 | the Free Software Foundation; either version 2, or (at your option)
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| 9 | any later version.
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| 10 |
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| 11 | GNU Classpath is distributed in the hope that it will be useful, but
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| 12 | WITHOUT ANY WARRANTY; without even the implied warranty of
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| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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| 14 | General Public License for more details.
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| 15 |
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| 16 | You should have received a copy of the GNU General Public License
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| 17 | along with GNU Classpath; see the file COPYING. If not, write to the
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| 18 | Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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| 19 | 02111-1307 USA.
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| 20 |
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| 21 | Linking this library statically or dynamically with other modules is
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| 22 | making a combined work based on this library. Thus, the terms and
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| 23 | conditions of the GNU General Public License cover the whole
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| 24 | combination.
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| 25 |
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| 26 | As a special exception, the copyright holders of this library give you
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| 27 | permission to link this library with independent modules to produce an
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| 28 | executable, regardless of the license terms of these independent
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| 29 | modules, and to copy and distribute the resulting executable under
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| 30 | terms of your choice, provided that you also meet, for each linked
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| 31 | independent module, the terms and conditions of the license of that
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| 32 | module. An independent module is a module which is not derived from
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| 33 | or based on this library. If you modify this library, you may extend
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| 34 | this exception to your version of the library, but you are not
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| 35 | obligated to do so. If you do not wish to do so, delete this
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| 36 | exception statement from your version. */
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| 37 |
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| 38 |
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| 39 | package java.io;
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| 40 |
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| 41 | // NOTE: This implementation is very similar to that of PipedOutputStream.
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| 42 | // If you fix a bug in here, chances are you should make a similar change to
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| 43 | // the PipedOutputStream code.
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| 44 |
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| 45 | /**
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| 46 | * This class writes its chars to a <code>PipedReader</code> to
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| 47 | * which it is connected.
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| 48 | * <p>
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| 49 | * It is highly recommended that a <code>PipedWriter</code> and its
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| 50 | * connected <code>PipedReader</code> be in different threads. If
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| 51 | * they are in the same thread, read and write operations could deadlock
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| 52 | * the thread.
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| 53 | *
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| 54 | * @author Aaron M. Renn ([email protected])
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| 55 | */
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| 56 | public class PipedWriter extends Writer
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| 57 | {
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| 58 | /** Target PipedReader to which this is connected. Null only if this
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| 59 | * Writer hasn't been connected yet. */
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| 60 | PipedReader sink;
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| 61 |
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| 62 | /** Set to true if close() has been called on this Writer. */
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| 63 | boolean closed;
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| 64 |
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| 65 | /** Buffer used to implement single-argument write */
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| 66 | char[] read_buf = new char[1];
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| 67 |
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| 68 | /**
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| 69 | * Create an unconnected PipedWriter. It must be connected
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| 70 | * to a <code>PipedReader</code> using the <code>connect</code>
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| 71 | * method prior to writing any data or an exception will be thrown.
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| 72 | */
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| 73 | public PipedWriter()
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| 74 | {
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| 75 | }
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| 76 |
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| 77 | /**
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| 78 | * Create a new <code>PipedWriter</code> instance
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| 79 | * to write to the specified <code>PipedReader</code>. This stream
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| 80 | * is then ready for writing.
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| 81 | *
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| 82 | * @param sink The <code>PipedReader</code> to connect this stream to.
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| 83 | *
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| 84 | * @exception IOException If <code>sink</code> has already been connected
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| 85 | * to a different PipedWriter.
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| 86 | */
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| 87 | public PipedWriter(PipedReader sink) throws IOException
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| 88 | {
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| 89 | sink.connect(this);
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| 90 | }
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| 91 |
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| 92 | /**
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| 93 | * Connects this object to the specified <code>PipedReader</code>
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| 94 | * object. This stream will then be ready for writing.
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| 95 | *
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| 96 | * @param sink The <code>PipedReader</code> to connect this stream to
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| 97 | *
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| 98 | * @exception IOException If the stream has not been connected or has
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| 99 | * been closed.
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| 100 | */
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| 101 | public void connect(PipedReader sink) throws IOException
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| 102 | {
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| 103 | if (sink != null)
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| 104 | throw new IOException ("Already connected");
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| 105 | sink.connect(this);
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| 106 | }
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| 107 |
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| 108 | /**
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| 109 | * Write a single char of date to the stream. Note that this method will
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| 110 | * block if the <code>PipedReader</code> to which this object is
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| 111 | * connected has a full buffer.
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| 112 | *
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| 113 | * @param b The char of data to be written, passed as an <code>int</code>.
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