java_gen: work in progress commit of java generator
diff --git a/java_gen/pre-written/src/main/java/org/openflow/types/IPv4.java b/java_gen/pre-written/src/main/java/org/openflow/types/IPv4.java
new file mode 100644
index 0000000..b4eb8cf
--- /dev/null
+++ b/java_gen/pre-written/src/main/java/org/openflow/types/IPv4.java
@@ -0,0 +1,129 @@
+package org.openflow.types;
+
+import org.jboss.netty.buffer.ChannelBuffer;
+import org.openflow.exceptions.OFParseError;
+import org.openflow.exceptions.OFShortRead;
+import org.openflow.exceptions.OFShortWrite;
+import org.openflow.protocol.OFObject;
+
+/**
+ * Wrapper around an IPv4 address
+ *
+ * @author Andreas Wundsam <andreas.wundsam@bigswitch.com>
+ */
+public class IPv4 implements OFObject {
+    static final int LENGTH = 4;
+    private final int rawValue;
+
+    private IPv4(final int rawValue) {
+        this.rawValue = rawValue;
+    }
+
+    public static IPv4 of(final byte[] address) {
+        if (address.length != LENGTH) {
+            throw new IllegalArgumentException(
+                    "Invalid byte array length for IPv4 address: " + address);
+        }
+
+        int raw =
+                (address[0] & 0xFF) << 24 | (address[1] & 0xFF) << 16
+                        | (address[2] & 0xFF) << 8 | (address[3] & 0xFF) << 0;
+        return IPv4.of(raw);
+    }
+
+    public static IPv4 of(final int raw) {
+        return new IPv4(raw);
+    }
+
+    public static IPv4 of(final String string) {
+        int start = 0;
+        int shift = 24;
+
+        int raw = 0;
+        while (shift >= 0) {
+            int end = string.indexOf('.', start);
+            if (end == start || !((shift > 0) ^ (end < 0)))
+                throw new IllegalArgumentException("IP Address not well formed: " + string);
+
+            String substr =
+                    end > 0 ? string.substring(start, end) : string.substring(start);
+            int val = Integer.parseInt(substr);
+            if (val < 0 || val > 255)
+                throw new IllegalArgumentException("IP Address not well formed: " + string);
+
+            raw |= val << shift;
+
+            shift -= 8;
+            start = end + 1;
+        }
+        return IPv4.of(raw);
+    }
+
+    public int getInt() {
+        return rawValue;
+    }
+
+    volatile byte[] bytesCache = null;
+
+    public byte[] getBytes() {
+        if (bytesCache == null) {
+            synchronized (this) {
+                if (bytesCache == null) {
+                    bytesCache =
+                            new byte[] { (byte) ((rawValue >>> 24) & 0xFF),
+                                    (byte) ((rawValue >>> 16) & 0xFF),
+                                    (byte) ((rawValue >>> 8) & 0xFF),
+                                    (byte) ((rawValue >>> 0) & 0xFF) };
+                }
+            }
+        }
+        return bytesCache;
+    }
+
+    @Override
+    public int getLength() {
+        return LENGTH;
+    }
+
+    public static IPv4 readFrom(final ChannelBuffer bb) throws OFParseError, OFShortRead {
+        return IPv4.of(bb.readInt());
+    }
+
+    @Override
+    public void writeTo(final ChannelBuffer bb) throws OFParseError, OFShortWrite {
+        bb.writeInt(rawValue);
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder res = new StringBuilder();
+        res.append((rawValue >> 24) & 0xFF).append('.');
+        res.append((rawValue >> 16) & 0xFF).append('.');
+        res.append((rawValue >> 8) & 0xFF).append('.');
+        res.append((rawValue >> 0) & 0xFF);
+        return res.toString();
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + rawValue;
+        return result;
+    }
+
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        IPv4 other = (IPv4) obj;
+        if (rawValue != other.rawValue)
+            return false;
+        return true;
+    }
+
+}