| /* LimitedLengthInputStream.java -- |
| Copyright (C) 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 gnu.java.net.protocol.http; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * InputStream that limits the total number of bytes that can be read |
| * from an underlying stream. In addition to limiting the number of |
| * bytes read, close() is not propagated to the underlying stream. |
| * |
| * @author David Daney (ddaney@avtrex.com) |
| */ |
| class LimitedLengthInputStream |
| extends InputStream |
| { |
| private long remainingLen; |
| private boolean restrictLen; |
| private HTTPConnection connection; |
| private boolean eof; |
| private InputStream in; |
| private boolean doClose; |
| |
| |
| private void handleClose() |
| throws IOException |
| { |
| eof = true; |
| if (doClose) |
| { |
| in.close(); |
| } |
| else |
| { |
| connection.release(); |
| } |
| in = null; |
| connection = null; |
| } |
| |
| /** |
| * Constructor. |
| * |
| * @param in the underlying stream |
| * |
| * @param maxLen the maximum number of bytes to read |
| * |
| * @param restrictLen if true the number of bytes that can be read |
| * from this stream will be limited to maxLen, otherwise the number |
| * of bytes is not restricted. |
| * |
| * @param con the HTTPConnection associated with this stream |
| * |
| * @param doClose if true con will be closed when finished reading, |
| * else it will be placed back in the connection pool. |
| * |
| */ |
| LimitedLengthInputStream(InputStream in, |
| long maxLen, |
| boolean restrictLen, |
| HTTPConnection con, |
| boolean doClose) |
| throws IOException |
| |
| { |
| this.in = in; |
| this.remainingLen = maxLen; |
| this.restrictLen = restrictLen; |
| this.connection = con; |
| this.doClose = doClose; |
| |
| if (restrictLen) |
| { |
| if (maxLen < 0) |
| throw new IllegalArgumentException(); |
| else if (maxLen == 0) |
| handleClose(); // Nothing to do, release the connection. |
| } |
| } |
| |
| public synchronized int read() |
| throws IOException |
| { |
| if (eof) |
| return -1; // EOF |
| |
| int r; |
| |
| if (restrictLen) |
| { |
| r = in.read(); |
| if (-1 != r) |
| remainingLen--; |
| |
| if (0 == remainingLen) |
| handleClose(); |
| } |
| else |
| { |
| r = in.read(); |
| if (r == -1) |
| handleClose(); |
| } |
| |
| return r; |
| } |
| |
| public int read(byte[] buffer) |
| throws IOException |
| { |
| return read(buffer, 0, buffer.length); |
| } |
| |
| public synchronized int read(byte[] buffer, int offset, int length) |
| throws IOException |
| { |
| if (eof) |
| return -1; // EOF |
| |
| if (restrictLen && length > remainingLen) |
| length = (int) remainingLen; |
| |
| int r = in.read(buffer, offset, length); |
| |
| if (-1 == r) |
| handleClose(); |
| |
| if (restrictLen && r > 0) |
| { |
| remainingLen -= r; |
| if (0 == remainingLen) |
| handleClose(); |
| } |
| return r; |
| } |
| |
| public synchronized long skip(long n) |
| throws IOException |
| { |
| |
| if (eof) |
| return 0; |
| |
| if (restrictLen && n > remainingLen) |
| n = remainingLen; |
| |
| long r = in.skip(n); |
| |
| if (restrictLen) |
| { |
| remainingLen -= r; |
| if (0 == remainingLen) |
| handleClose(); |
| } |
| return r; |
| } |
| |
| public synchronized int available() |
| throws IOException |
| { |
| if (eof) |
| return 0; |
| |
| int a = in.available(); |
| if (restrictLen && a > remainingLen) |
| a = (int)remainingLen; |
| return a; |
| } |
| |
| public synchronized void close() |
| throws IOException |
| { |
| if (eof) |
| return; |
| |
| // If we get to here, the stream was not fully read. Just throw |
| // it away. |
| |
| doClose = true; |
| |
| handleClose(); |
| } |
| } |