/* * Copyright (c) 2005, 2007, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package sun.net.httpserver; import java.io.*;import com.sun.net.httpserver.*;import com.sun.net.httpserver.spi.*; /** * a (filter) input stream which can tell us if bytes are "left over" * on the underlying stream which can be read (without blocking) * on another instance of this class. * * The class can also report if all bytes "expected" to be read * were read, by the time close() was called. In that case, * bytes may be drained to consume them (by calling drain() ). * * isEOF() returns true, when all expected bytes have been read */abstract class LeftOverInputStream extends FilterInputStream {    ExchangeImpl t;    ServerImpl server;    protected boolean closed = false;    protected boolean eof = false;    byte[] one = new byte [1];     public LeftOverInputStream (ExchangeImpl t, InputStream src) {        super (src);        this.t = t;        this.server = t.getServerImpl();    }    /**     * if bytes are left over buffered on *the UNDERLYING* stream     */    public boolean isDataBuffered () throws IOException {        assert eof;        return super.available() > 0;    }     public void close () throws IOException {        if (closed) {            return;        }        closed = true;        if (!eof) {            eof = drain (ServerConfig.getDrainAmount());        }    }     public boolean isClosed () {        return closed;    }     public boolean isEOF () {        return eof;    }     protected abstract int readImpl (byte[]b, int off, int len) throws IOException;     public synchronized int read () throws IOException {        if (closed) {            throw new IOException ("Stream is closed");        }        int c = readImpl (one, 0, 1);        if (c == -1 || c == 0) {            return c;        } else {            return one[0] & 0xFF;        }    }     public synchronized int read (byte[]b, int off, int len) throws IOException {        if (closed) {            throw new IOException ("Stream is closed");        }        return readImpl (b, off, len);    }     /**     * read and discard up to l bytes or "eof" occurs,     * (whichever is first). Then return true if the stream     * is at eof (ie. all bytes were read) or false if not     * (still bytes to be read)     */    public boolean drain (long l) throws IOException {        int bufSize = 2048;        byte[] db = new byte [bufSize];        while (l > 0) {            long len = readImpl (db, 0, bufSize);            if (len == -1) {                eof = true;                return true;            } else {                l = l - len;            }        }        return false;    }}