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Diffstat (limited to 'libjava/java/io/InputStreamReader.java')
| -rw-r--r-- | libjava/java/io/InputStreamReader.java | 332 |
1 files changed, 0 insertions, 332 deletions
diff --git a/libjava/java/io/InputStreamReader.java b/libjava/java/io/InputStreamReader.java deleted file mode 100644 index 91568c5..0000000 --- a/libjava/java/io/InputStreamReader.java +++ /dev/null @@ -1,332 +0,0 @@ -/* InputStreamReader.java -- Reader than transforms bytes to chars - Copyright (C) 1998, 1999, 2001, 2003, 2004, 2005 Free Software Foundation, Inc. - -This file is part of GNU Classpath. - -GNU Classpath 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, or (at your option) -any later version. - -GNU Classpath 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 GNU Classpath; see the file COPYING. If not, write to the -Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301 USA. - -Linking this library statically or dynamically with other modules is -making a combined work based on this library. Thus, the terms and -conditions of the GNU General Public License cover the whole -combination. - -As a special exception, the copyright holders of this library give you -permission to link this library with independent modules to produce an -executable, regardless of the license terms of these independent -modules, and to copy and distribute the resulting executable under -terms of your choice, provided that you also meet, for each linked -independent module, the terms and conditions of the license of that -module. An independent module is a module which is not derived from -or based on this library. If you modify this library, you may extend -this exception to your version of the library, but you are not -obligated to do so. If you do not wish to do so, delete this -exception statement from your version. */ - - -package java.io; - -import gnu.gcj.convert.*; -import java.nio.charset.Charset; -import java.nio.charset.CharsetDecoder; - -/** - * This class reads characters from a byte input stream. The characters - * read are converted from bytes in the underlying stream by a - * decoding layer. The decoding layer transforms bytes to chars according - * to an encoding standard. There are many available encodings to choose - * from. The desired encoding can either be specified by name, or if no - * encoding is selected, the system default encoding will be used. The - * system default encoding name is determined from the system property - * <code>file.encoding</code>. The only encodings that are guaranteed to - * be availalbe are "8859_1" (the Latin-1 character set) and "UTF8". - * Unforunately, Java does not provide a mechanism for listing the - * ecodings that are supported in a given implementation. - * <p> - * Here is a list of standard encoding names that may be available: - * <p> - * <ul> - * <li>8859_1 (ISO-8859-1/Latin-1)</li> - * <li>8859_2 (ISO-8859-2/Latin-2)</li> - * <li>8859_3 (ISO-8859-3/Latin-3)</li> - * <li>8859_4 (ISO-8859-4/Latin-4)</li> - * <li>8859_5 (ISO-8859-5/Latin-5)</li> - * <li>8859_6 (ISO-8859-6/Latin-6)</li> - * <li>8859_7 (ISO-8859-7/Latin-7)</li> - * <li>8859_8 (ISO-8859-8/Latin-8)</li> - * <li>8859_9 (ISO-8859-9/Latin-9)</li> - * <li>ASCII (7-bit ASCII)</li> - * <li>UTF8 (UCS Transformation Format-8)</li> - * <li>More later</li> - * </ul> - * <p> - * It is recommended that applications do not use - * <code>InputStreamReader</code>'s - * directly. Rather, for efficiency purposes, an object of this class - * should be wrapped by a <code>BufferedReader</code>. - * <p> - * Due to a deficiency the Java class library design, there is no standard - * way for an application to install its own byte-character encoding. - * - * @see BufferedReader - * @see InputStream - * - * @author Aaron M. Renn (arenn@urbanophile.com) - * @author Per Bothner (bothner@cygnus.com) - * @date April 22, 1998. - */ -public class InputStreamReader extends Reader -{ - BufferedInputStream in; - - // Buffer of chars read from in and converted but not consumed. - char[] work; - // Next available character (in work buffer) to read. - int wpos; - // Last available character (in work buffer) to read. - int wcount; - - /* - * This is the byte-character decoder class that does the reading and - * translation of bytes from the underlying stream. - */ - BytesToUnicode converter; - - /** - * This method initializes a new instance of <code>InputStreamReader</code> - * to read from the specified stream using the default encoding. - * - * @param in The <code>InputStream</code> to read from - */ - public InputStreamReader(InputStream in) - { - this(in, BytesToUnicode.getDefaultDecoder()); - } - - /** - * This method initializes a new instance of <code>InputStreamReader</code> - * to read from the specified stream using a caller supplied character - * encoding scheme. Note that due to a deficiency in the Java language - * design, there is no way to determine which encodings are supported. - * - * @param in The <code>InputStream</code> to read from - * @param encoding_name The name of the encoding scheme to use - * - * @exception UnsupportedEncodingException If the encoding scheme - * requested is not available. - */ - public InputStreamReader(InputStream in, String encoding_name) - throws UnsupportedEncodingException - { - this(in, BytesToUnicode.getDecoder(encoding_name)); - } - - /** - * Creates an InputStreamReader that uses a decoder of the given - * charset to decode the bytes in the InputStream into - * characters. - */ - public InputStreamReader(InputStream in, Charset charset) - { - this(in, new BytesToCharsetAdaptor(charset)); - } - - /** - * Creates an InputStreamReader that uses the given charset decoder - * to decode the bytes in the InputStream into characters. - */ - public InputStreamReader(InputStream in, CharsetDecoder decoder) - { - this(in, new BytesToCharsetAdaptor(decoder)); - } - - private InputStreamReader(InputStream in, BytesToUnicode decoder) - { - // FIXME: someone could pass in a BufferedInputStream whose buffer - // is smaller than the longest encoded character for this - // encoding. We will probably go into an infinite loop in this - // case. We probably ought to just have our own byte buffering - // here. - this.in = in instanceof BufferedInputStream - ? (BufferedInputStream) in - : new BufferedInputStream(in); - /* Don't need to call super(in) here as long as the lock gets set. */ - this.lock = in; - converter = decoder; - converter.setInput(this.in.buf, 0, 0); - } - - /** - * This method closes this stream, as well as the underlying - * <code>InputStream</code>. - * - * @exception IOException If an error occurs - */ - public void close() throws IOException - { - synchronized (lock) - { - if (in != null) - in.close(); - in = null; - work = null; - wpos = wcount = 0; - } - } - - /** - * This method returns the name of the encoding that is currently in use - * by this object. If the stream has been closed, this method is allowed - * to return <code>null</code>. - * - * @return The current encoding name - */ - public String getEncoding() - { - return in != null ? converter.getName() : null; - } - - /** - * This method checks to see if the stream is read to be read. It - * will return <code>true</code> if is, or <code>false</code> if it is not. - * If the stream is not ready to be read, it could (although is not required - * to) block on the next read attempt. - * - * @return <code>true</code> if the stream is ready to be read, - * <code>false</code> otherwise - * - * @exception IOException If an error occurs - */ - public boolean ready() throws IOException - { - synchronized (lock) - { - if (in == null) - throw new IOException("Stream closed"); - - if (wpos < wcount) - return true; - - // According to the spec, an InputStreamReader is ready if its - // input buffer is not empty (above), or if bytes are - // available on the underlying byte stream. - return in.available () > 0; - } - } - - /** - * This method reads up to <code>length</code> characters from the stream into - * the specified array starting at index <code>offset</code> into the - * array. - * - * @param buf The character array to recieve the data read - * @param offset The offset into the array to start storing characters - * @param length The requested number of characters to read. - * - * @return The actual number of characters read, or -1 if end of stream. - * - * @exception IOException If an error occurs - */ - public int read (char[] buf, int offset, int length) throws IOException - { - synchronized (lock) - { - if (in == null) - throw new IOException("Stream closed"); - - if (length == 0) - return 0; - - int wavail = wcount - wpos; - if (wavail <= 0) - { - // Nothing waiting, so refill their buffer. - return refill(buf, offset, length); - } - - if (length > wavail) - length = wavail; - System.arraycopy(work, wpos, buf, offset, length); - wpos += length; - return length; - } - } - - /** - * This method reads a single character of data from the stream. - * - * @return The char read, as an int, or -1 if end of stream. - * - * @exception IOException If an error occurs - */ - public int read() throws IOException - { - synchronized (lock) - { - if (in == null) - throw new IOException("Stream closed"); - - int wavail = wcount - wpos; - if (wavail <= 0) - { - // Nothing waiting, so refill our internal buffer. - wpos = wcount = 0; - if (work == null) - work = new char[100]; - int count = refill(work, 0, work.length); - if (count == -1) - return -1; - wcount += count; - } - - return work[wpos++]; - } - } - - // Read more bytes and convert them into the specified buffer. - // Returns the number of converted characters or -1 on EOF. - private int refill(char[] buf, int offset, int length) throws IOException - { - for (;;) - { - // We have knowledge of the internals of BufferedInputStream - // here. Eww. - // BufferedInputStream.refill() can only be called when - // `pos>=count'. - boolean r = in.pos < in.count || in.refill (); - if (! r) - return -1; - converter.setInput(in.buf, in.pos, in.count); - int count = converter.read(buf, offset, length); - - // We might have bytes but not have made any progress. In - // this case we try to refill. If refilling fails, we assume - // we have a malformed character at the end of the stream. - if (count == 0 && converter.inpos == in.pos) - { - in.mark(in.count); - if (! in.refill ()) - throw new CharConversionException (); - in.reset(); - } - else - { - in.skip(converter.inpos - in.pos); - if (count > 0) - return count; - } - } - } -} |