diff --git a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/DatapathId.java b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/DatapathId.java
index a43e5d6..2e7a59b 100644
--- a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/DatapathId.java
+++ b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/DatapathId.java
@@ -1,5 +1,7 @@
 package org.projectfloodlight.openflow.types;
 
+import javax.annotation.Nonnull;
+
 import org.projectfloodlight.openflow.annotations.Immutable;
 import org.projectfloodlight.openflow.util.HexString;
 
@@ -38,13 +40,13 @@
     }
 
     /**
-     * Creates a {@link DatapathId} from an {@link MacAddress}. This factory
+     * Creates a {@link DatapathId} from a {@link MacAddress}. This factory
      * method assumes that the {@link DatapathId} is composed of two zero bytes
      * appended by the {@link MacAddress}'s 6 bytes.
      * @param mac the {@link MacAddress} to create the {@link DatapathId} from
      * @return a {@link DatapathId} derived from the supplied {@link MacAddress}
      */
-    public static DatapathId of(MacAddress mac) {
+    public static DatapathId of(@Nonnull MacAddress mac) {
         byte[] zeroBytes = new byte[]{0,0};
         byte[] fullBytes = Bytes.concat(zeroBytes, mac.getBytes());
         return DatapathId.of(fullBytes);
diff --git a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/MacAddress.java b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/MacAddress.java
index 89debf0..b026b6c 100644
--- a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/MacAddress.java
+++ b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/MacAddress.java
@@ -8,6 +8,8 @@
 import org.projectfloodlight.openflow.exceptions.OFParseError;
 import org.projectfloodlight.openflow.util.HexString;
 
+import com.google.common.base.Preconditions;
+import com.google.common.base.Strings;
 import com.google.common.hash.PrimitiveSink;
 import com.google.common.primitives.Longs;
 
@@ -33,6 +35,10 @@
     private static final long LLDP_MAC_ADDRESS_MASK = 0xfffffffffff0L;
     private static final long LLDP_MAC_ADDRESS_VALUE = 0x0180c2000000L;
 
+    private static final String FORMAT_ERROR = "Mac address is not well-formed. " +
+            "It must consist of 6 hex digit pairs separated by colons: ";
+    private static final int STRING_LENGTH = 6 * 2 + 5;
+
     private MacAddress(final long rawValue) {
         this.rawValue = rawValue;
     }
@@ -66,17 +72,14 @@
      */
     @Nonnull
     public static MacAddress of(@Nonnull final String macString) throws IllegalArgumentException {
-        if (macString == null) {
-            throw new NullPointerException("macString must not be null");
-        }
+        Preconditions.checkArgument(!Strings.isNullOrEmpty(macString),
+                                    "macString must not be null or empty");
+        Preconditions.checkArgument(macString.length() == (STRING_LENGTH),
+                FORMAT_ERROR + macString);
+
         int index = 0;
         int shift = 40;
-        final String FORMAT_ERROR = "Mac address is not well-formed. " +
-                "It must consist of 6 hex digit pairs separated by colons: ";
-
         long raw = 0;
-        if (macString.length() != 6 * 2 + 5)
-            throw new IllegalArgumentException(FORMAT_ERROR + macString);
 
         while (shift >= 0) {
             int digit1 = Character.digit(macString.charAt(index++), 16);
@@ -94,6 +97,21 @@
         return MacAddress.of(raw);
     }
 
+    /**
+     * Creates a {@link MacAddress} from a {@link DatapathId}. This factory
+     * method assumes that the {@link MacAddress} is composed of the last six
+     * bytes of the supplied {@link DatapathId}.
+     * @param dpid the {@link DatapathId} to create the {@link MacAddress} from
+     * @return a {@link MacAddress} derived from the supplied {@link DatapathId}
+     */
+    public static MacAddress of(@Nonnull DatapathId dpid) {
+        Preconditions.checkNotNull(dpid, "dpid must not be null");
+
+        byte[] dpidBytes = dpid.getBytes();
+        byte[] macBytes = Arrays.copyOfRange(dpidBytes, 2, 8);
+        return MacAddress.of(macBytes);
+    }
+
     private volatile byte[] bytesCache = null;
 
     public byte[] getBytes() {