--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.httpserver/share/classes/sun/net/httpserver/LeftOverInputStream.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,125 @@
+/*
+ * 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 {
+    final ExchangeImpl t;
+    final 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) {
+            if (server.isFinishing()) {
+                break;
+            }
+            long len = readImpl (db, 0, bufSize);
+            if (len == -1) {
+                eof = true;
+                return true;
+            } else {
+                l = l - len;
+            }
+        }
+        return false;
+    }
+}