diff --git a/java_gen/java_utils.py b/java_gen/java_utils.py
new file mode 100644
index 0000000..c55b275
--- /dev/null
+++ b/java_gen/java_utils.py
@@ -0,0 +1,215 @@
+import os
+import errno
+import re
+import subprocess
+import time
+
+def name_c_to_camel(name):
+    """ 'of_stats_reply' -> 'ofStatsReply' """
+    tokens = name.split('_')
+    for i in range(1, len(tokens)):
+            tokens[i] = tokens[i].title()
+    return "".join(tokens)
+
+def name_c_to_caps_camel(name):
+    """ 'of_stats_reply' to 'OFStatsReply' """
+    camel = name_c_to_camel(name.title())
+    if camel.startswith('Of'):
+        return camel.replace('Of','OF',1)
+    else:
+        return camel
+
+
+class JType(object):
+    """ Wrapper class to hold C to Java type conversion information """
+    def __init__(self, pub_type, priv_type=None, size=None, read_op=None, write_op=None):
+        self.pub_type = pub_type    # the type we expose externally, e.g. 'U8'
+        if priv_type is None:
+            priv_type = pub_type
+        self.priv_type = priv_type  # the internal storage type
+        self.size = size            # bytes on the wire; None == variable length or hard to calc
+        if read_op is None:
+            read_op = 'ChannelUtils.read%s(this, "$name", bb)' % self.pub_type
+        if write_op is None:
+            write_op = 'ChannelUtils.write($name)'
+        self._read_op = read_op
+        self.write_op = write_op
+
+    @property
+    def public_type(self):
+        """ return the public type """
+        return self.pub_type
+
+    def priv(self):
+        """ return the public type """
+        return self.priv_type
+
+    def has_priv(self):
+        """ Is the private type different from the public one?"""
+        return self.pub_type != self.priv_type
+
+    def read_op(self, version=None):
+        if callable(self._read_op):
+            return self._read_op(version)
+        else:
+            return self._read_op
+
+hello_elem_list = JType("List<OFHelloElement>",
+        read_op = 'ChannelUtils.readHelloElementList(bb)',
+        write_op = 'ChannelUtils.writeHelloElementList(bb)'
+        )
+
+u8 =  JType('byte',  size=1, read_op='bb.readByte()',
+        write_op='bb.writeByte($name)')
+u16 = JType('int', 'int', size=2, read_op='U16.f(bb.readShort())',
+        write_op='bb.writeShort(U16.t($name))')
+u32 = JType('int', 'int',   size=4, read_op='bb.readInt()',
+        write_op='bb.writeInt($name)')
+u64 = JType('U64', 'U64', size=8, read_op='U64.of(bb.readLong())',
+        write_op='bb.writeLong($name.getLong())')
+of_port= JType('OFPort',size=None,
+        read_op=lambda(version): 'OFPort.ofShort(bb.readShort())' if version.int_version < 2 else 'OFPort.ofInt(bb.readInt())',
+        write_op='$name.writeTo(bb)')
+one_byte_array = JType('byte[]', size=1,
+        read_op = 'ChannelUtils.readBytes(bb, 1)',
+        write_op = 'ChannelUtils.writeBytes(bb, $name)')
+two_byte_array = JType('byte[]', size=2,
+        read_op = 'ChannelUtils.readBytes(bb, 2)',
+        write_op = 'ChannelUtils.writeBytes(bb, $name)')
+three_byte_array = JType('byte[]', size=3,
+        read_op = 'ChannelUtils.readBytes(bb, 3)',
+        write_op = 'ChannelUtils.writeBytes(bb, $name)')
+four_byte_array = JType('byte[]', size=4,
+        read_op = 'ChannelUtils.readBytes(bb, 4)',
+        write_op = 'ChannelUtils.writeBytes(bb, $name)')
+five_byte_array = JType('byte[]', size=5,
+        read_op = 'ChannelUtils.readBytes(bb, 5)',
+        write_op = 'ChannelUtils.writeBytes(bb, $name)')
+six_byte_array = JType('byte[]', size=6,
+        read_op = 'ChannelUtils.readBytes(bb, 6)',
+        write_op = 'ChannelUtils.writeBytes(bb, $name)')
+seven_byte_array = JType('byte[]', size=7,
+        read_op = 'ChannelUtils.readBytes(bb, 7)',
+        write_op = 'ChannelUtils.writeBytes(bb, $name)')
+actions_list = JType('List<OFAction>', size='ChannelUtils.calcListSize($name)',
+        read_op = 'ChannelUtils.readActionsList(bb, length - MINIMUM_LENGTH)',
+        write_op = 'ChannelUtils.writeList(this, $name)')
+instructions_list = JType('List<OFInstruction>', size='ChannelUtils.calcListSize($name)',
+        read_op = 'ChannelUtils.readInstructionsList(bb, length - MINIMUM_LENGTH)',
+        write_op = 'ChannelUtils.writeList(this, $name)')
+buckets_list = JType('List<OFBucket>', size='ChannelUtils.calcListSize($name)',
+        read_op = 'ChannelUtils.readBucketList(bb, length - MINIMUM_LENGTH)',
+        write_op = 'ChannelUtils.writeList(this, $name)')
+port_desc_list = JType('List<OFPhysicalPort>', size='ChannelUtils.calcListSize($name)',
+        read_op = 'ChannelUtils.readPhysicalPortList(bb, length - MINIMUM_LENGTH)',
+        write_op = 'ChannelUtils.writeList(this, $name)')
+port_desc = JType('OFPhysicalPort', size='$name.getLength()',
+        read_op = 'ChannelUtils.readPhysicalPort(bb)',
+        write_op = 'ChannelUtils.write(this, $name)')
+packet_queue_list = JType('List<OFPacketQueue>', size='ChannelUtils.calcListSize($name)',
+        read_op = 'ChannelUtils.readPacketQueueList(bb, length - MINIMUM_LENGTH)',
+        write_op = 'ChannelUtils.writeList(this, $name)')
+octets = JType('byte[]', size="length - MINIMUM_LENGTH",
+        read_op = 'ChannelUtils.readBytes(bb, length - MINIMUM_LENGTH)',
+        write_op = 'ChannelUtils.writeBytes(bb, this.$name)')
+of_match = JType('Match', size="$name.getLength()",
+        read_op = 'ChannelUtils.readOFMatch(bb)',
+        write_op = 'ChannelUtils.writeOFMatch(this, $name)')
+flow_mod_cmd = JType('OFFlowModCmd', size="$name.getLength()",
+        read_op = 'ChannelUtils.readOFFlowModCmd(bb)',
+        write_op = 'ChannelUtils.writeOFFlowModCmd(this, $name)')
+mac_addr = JType('MacAddress', 'byte[]', size=6,
+        read_op = 'MacAddress.readFrom(bb)',
+        write_op = 'ChannelUtils.writeBytes(bb, $name)')
+bsn_interface_list = JType("List<OFBsnInterface>",
+        read_op = 'ChannelUtils.readBsnInterfaceList(bb)',
+        write_op = 'ChannelUtils.writeBsnInterfaceList(bb)'
+        )
+meter_band_list = JType("List<OFMeterBand>",
+        read_op = 'ChannelUtils.readMeterBandList(bb)',
+        write_op = 'ChannelUtils.writeMeterBandList(bb, $name)'
+        )
+
+
+
+
+
+default_mtype_to_jtype_convert_map = {
+        'uint8_t' : u8,
+        'uint16_t' : u16,
+        'uint32_t' : u32,
+        'uint64_t' : u64,
+        'uint8_t[1]' : one_byte_array,
+        'uint8_t[2]' : two_byte_array,
+        'uint8_t[3]' : three_byte_array,
+        'uint8_t[4]' : four_byte_array,
+        'uint8_t[5]' : five_byte_array,
+        'uint8_t[6]' : six_byte_array,
+        'uint8_t[7]' : seven_byte_array,
+        'of_port_no_t' : of_port,
+        'of_list_action_t' : actions_list,
+        'of_list_instruction_t' : instructions_list,
+        'of_list_bucket_t': buckets_list,
+        'of_list_port_desc_t' : port_desc_list,
+        'of_list_packet_queue_t' : packet_queue_list,
+        'of_octets_t' : octets,
+        'of_match_t': of_match,
+        'of_fm_cmd_t': flow_mod_cmd,
+        'of_mac_addr_t': mac_addr,
+        'of_port_desc_t': port_desc,
+        'of_list_bsn_interface_t': bsn_interface_list,
+        'of_list_hello_elem_t': hello_elem_list,
+        'of_list_meter_band_t': meter_band_list
+        }
+
+## This is where we drop in special case handling for certain types
+exceptions = {
+        'OFPacketIn': {
+            'data' : octets
+            },
+        }
+
+
+def convert_to_jtype(obj_name, field_name, c_type):
+    """ Convert from a C type ("uint_32") to a java type ("U32")
+    and return a JType object with the size, internal type, and marshalling functions"""
+    if obj_name in exceptions and field_name in exceptions[obj_name]:
+        return exceptions[obj_name][field_name]
+    elif c_type in default_mtype_to_jtype_convert_map:
+        return default_mtype_to_jtype_convert_map[c_type]
+    else:
+        print "WARN: Couldn't find java type conversion for '%s' in %s:%s" % (c_type, obj_name, field_name)
+        jtype = name_c_to_caps_camel(c_type)      # not sure... try to fake it
+        return JType(jtype)
+
+
+def mkdir_p(path):
+    """ Emulates `mkdir -p` """
+    try:
+        os.makedirs(path)
+    except OSError as exc: # Python >2.5
+        if exc.errno == errno.EEXIST:
+            pass
+        else: raise
+
+def copy_file_with_boiler_plate(src_name, dst_name, with_boiler=True):
+    with open("java_gen/pre-written/%s" % src_name, "r") as src:
+        with open(dst_name, "w") as dst:
+            if with_boiler:
+                print_boiler_plate(os.path.basename(dst_name), dst)
+            dst.writelines(src.readlines())
+
+def frob(s, **kwargs):
+    """ Step through string s and for each key in kwargs,
+         replace $key with kwargs[key] in s.
+    """
+    for k,v in kwargs.iteritems():
+        s = s.replace('$%s' % k, v)
+    return s
+
+def copy_prewrite_tree(basedir):
+    """ Recursively copy the directory structure from ./java_gen/pre-write
+       into $basedir"""
+    print "Copying pre-written files into %s" % basedir
+#    subprocess.call("cd java_gen/pre-written && tar cpf - . | ( cd ../../%s && tar xvpf - )" % basedir,
+#            shell=True)