--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/io/BufferedOutputStream.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,145 @@
+/*
+ * Copyright (c) 1994, 2015, 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 java.io;
+
+/**
+ * The class implements a buffered output stream. By setting up such
+ * an output stream, an application can write bytes to the underlying
+ * output stream without necessarily causing a call to the underlying
+ * system for each byte written.
+ *
+ * @author  Arthur van Hoff
+ * @since   1.0
+ */
+public class BufferedOutputStream extends FilterOutputStream {
+    /**
+     * The internal buffer where data is stored.
+     */
+    protected byte buf[];
+
+    /**
+     * The number of valid bytes in the buffer. This value is always
+     * in the range {@code 0} through {@code buf.length}; elements
+     * {@code buf[0]} through {@code buf[count-1]} contain valid
+     * byte data.
+     */
+    protected int count;
+
+    /**
+     * Creates a new buffered output stream to write data to the
+     * specified underlying output stream.
+     *
+     * @param   out   the underlying output stream.
+     */
+    public BufferedOutputStream(OutputStream out) {
+        this(out, 8192);
+    }
+
+    /**
+     * Creates a new buffered output stream to write data to the
+     * specified underlying output stream with the specified buffer
+     * size.
+     *
+     * @param   out    the underlying output stream.
+     * @param   size   the buffer size.
+     * @exception IllegalArgumentException if size <= 0.
+     */
+    public BufferedOutputStream(OutputStream out, int size) {
+        super(out);
+        if (size <= 0) {
+            throw new IllegalArgumentException("Buffer size <= 0");
+        }
+        buf = new byte[size];
+    }
+
+    /** Flush the internal buffer */
+    private void flushBuffer() throws IOException {
+        if (count > 0) {
+            out.write(buf, 0, count);
+            count = 0;
+        }
+    }
+
+    /**
+     * Writes the specified byte to this buffered output stream.
+     *
+     * @param      b   the byte to be written.
+     * @exception  IOException  if an I/O error occurs.
+     */
+    @Override
+    public synchronized void write(int b) throws IOException {
+        if (count >= buf.length) {
+            flushBuffer();
+        }
+        buf[count++] = (byte)b;
+    }
+
+    /**
+     * Writes <code>len</code> bytes from the specified byte array
+     * starting at offset <code>off</code> to this buffered output stream.
+     *
+     * <p> Ordinarily this method stores bytes from the given array into this
+     * stream's buffer, flushing the buffer to the underlying output stream as
+     * needed.  If the requested length is at least as large as this stream's
+     * buffer, however, then this method will flush the buffer and write the
+     * bytes directly to the underlying output stream.  Thus redundant
+     * <code>BufferedOutputStream</code>s will not copy data unnecessarily.
+     *
+     * @param      b     the data.
+     * @param      off   the start offset in the data.
+     * @param      len   the number of bytes to write.
+     * @exception  IOException  if an I/O error occurs.
+     */
+    @Override
+    public synchronized void write(byte b[], int off, int len) throws IOException {
+        if (len >= buf.length) {
+            /* If the request length exceeds the size of the output buffer,
+               flush the output buffer and then write the data directly.
+               In this way buffered streams will cascade harmlessly. */
+            flushBuffer();
+            out.write(b, off, len);
+            return;
+        }
+        if (len > buf.length - count) {
+            flushBuffer();
+        }
+        System.arraycopy(b, off, buf, count, len);
+        count += len;
+    }
+
+    /**
+     * Flushes this buffered output stream. This forces any buffered
+     * output bytes to be written out to the underlying output stream.
+     *
+     * @exception  IOException  if an I/O error occurs.
+     * @see        java.io.FilterOutputStream#out
+     */
+    @Override
+    public synchronized void flush() throws IOException {
+        flushBuffer();
+        out.flush();
+    }
+}