--- /dev/null	2016-04-26 16:08:43.098618272 +0100
+++ new/src/java.httpclient/share/classes/java/net/http/Http2Frame.java	2016-04-29 11:47:40.327376495 +0100
@@ -0,0 +1,211 @@
+/*
+ * Copyright (c) 2015, 2016, 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
+ */
+package java.net.http;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+/**
+ * When sending a frame, the length field must be set in sub-class
+ * by calling computeLength()
+ */
+abstract class Http2Frame {
+
+    int length = -1;
+    int type;
+    int streamid;
+    int flags;
+
+    // called when reading in only
+    void initCommon(int length, int type, int streamid, int flags) {
+        this.length = length;
+        this.type = type;
+        this.streamid = streamid;
+        this.flags = flags;
+    }
+
+    public int length() {
+        return length;
+    }
+
+    public int type() {
+        return type;
+    }
+
+    public int streamid() {
+        return streamid;
+    }
+
+    public void setFlag(int flag) {
+        flags |= flag;
+    }
+
+    public void setFlags(int flags) {
+        this.flags = flags;
+    }
+
+    public int getFlags() {
+        return flags;
+    }
+
+    public boolean getFlag(int flag) {
+        return (flags & flag) != 0;
+    }
+
+    public void clearFlag(int flag) {
+        flags &= 0xffffffff ^ flag;
+    }
+
+    public void streamid(int streamid) {
+        this.streamid = streamid;
+    }
+
+    abstract void readIncomingImpl(ByteBufferConsumer bc) throws IOException;
+
+    /**
+     * assume given array contains at least one complete frame.
+     */
+    static Http2Frame readIncoming(ByteBufferConsumer bc) throws IOException {
+        int x = bc.getInt();
+        int length = x >> 8;
+        int type = x & 0xff;
+        int flags = bc.getByte();
+        int streamid = bc.getInt();
+        Http2Frame f = null;
+        switch (type) {
+          case DataFrame.TYPE:
+            f = new DataFrame();
+            break;
+          case HeadersFrame.TYPE:
+            f = new HeadersFrame();
+            break;
+          case ContinuationFrame.TYPE:
+            f = new ContinuationFrame();
+            break;
+          case ResetFrame.TYPE:
+            f = new ResetFrame();
+            break;
+          case PriorityFrame.TYPE:
+            f = new PriorityFrame();
+            break;
+          case SettingsFrame.TYPE:
+            f = new SettingsFrame();
+            break;
+          case GoAwayFrame.TYPE:
+            f = new GoAwayFrame();
+            break;
+          case PingFrame.TYPE:
+            f = new PingFrame();
+            break;
+          case PushPromiseFrame.TYPE:
+            f = new PushPromiseFrame();
+            break;
+          case WindowUpdateFrame.TYPE:
+            f = new WindowUpdateFrame();
+            break;
+          default:
+            String msg = Integer.toString(type);
+            throw new IOException("unknown frame type " + msg);
+        }
+        f.initCommon(length, type, streamid, flags);
+        f.readIncomingImpl(bc);
+        return f;
+    }
+
+    public String typeAsString() {
+        return asString(this.type);
+    }
+
+    public static String asString(int type) {
+        switch (type) {
+          case DataFrame.TYPE:
+            return "DATA";
+          case HeadersFrame.TYPE:
+            return "HEADERS";
+          case ContinuationFrame.TYPE:
+            return "CONTINUATION";
+          case ResetFrame.TYPE:
+            return "RESET";
+          case PriorityFrame.TYPE:
+            return "PRIORITY";
+          case SettingsFrame.TYPE:
+            return "SETTINGS";
+          case GoAwayFrame.TYPE:
+            return "GOAWAY";
+          case PingFrame.TYPE:
+            return "PING";
+          case PushPromiseFrame.TYPE:
+            return "PUSH_PROMISE";
+          case WindowUpdateFrame.TYPE:
+            return "WINDOW_UPDATE";
+          default:
+            return "UNKNOWN";
+        }
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder sb = new StringBuilder();
+        sb.append(typeAsString())
+                .append(": length=")
+                .append(Integer.toString(length))
+                .append(", streamid=")
+                .append(streamid)
+                .append(", flags=");
+
+        int f = flags;
+        int i = 0;
+        if (f == 0) {
+            sb.append("0 ");
+        } else {
+            while (f != 0) {
+                if ((f & 1) == 1) {
+                    sb.append(flagAsString(1 << i))
+                      .append(' ');
+                }
+                f = f >> 1;
+                i++;
+            }
+        }
+        return sb.toString();
+    }
+
+    // Override
+    String flagAsString(int f) {
+        return "unknown";
+    }
+
+    abstract void computeLength();
+
+    void writeOutgoing(ByteBufferGenerator bg) {
+        if (length == -1) {
+            throw new InternalError("Length not set on outgoing frame");
+        }
+        ByteBuffer buf = bg.getBuffer(9);
+        int x = (length << 8) + type;
+        buf.putInt(x);
+        buf.put((byte)flags);
+        buf.putInt(streamid);
+    }
+}