diff --git a/java_gen/pre-written/src/main/java/org/openflow/exceptions/NonExistantMessage.java b/java_gen/pre-written/src/main/java/org/openflow/exceptions/NonExistantMessage.java
new file mode 100644
index 0000000..2d82ba2
--- /dev/null
+++ b/java_gen/pre-written/src/main/java/org/openflow/exceptions/NonExistantMessage.java
@@ -0,0 +1,30 @@
+package org.openflow.exceptions;
+
+/**
+ * Error: someone asked to create an OFMessage with wireformat type and version,
+ * but that doesn't exist
+ *
+ * @author capveg
+ */
+public class NonExistantMessage extends Exception {
+
+    private static final long serialVersionUID = 1L;
+    byte type;
+    byte version;
+
+    /**
+     * Error: someone asked to create an OFMessage with wireformat type and
+     * version, but that doesn't exist
+     *
+     * @param type
+     *            the wire format
+     * @param version
+     *            the OpenFlow wireformat version number, e.g. 1 == v1.1, 2 =
+     *            v1.2, etc.
+     */
+    public NonExistantMessage(final byte type, final byte version) {
+        this.type = type;
+        this.version = version;
+    }
+
+}
diff --git a/java_gen/pre-written/src/main/java/org/openflow/exceptions/OFParseError.java b/java_gen/pre-written/src/main/java/org/openflow/exceptions/OFParseError.java
new file mode 100644
index 0000000..76afc79
--- /dev/null
+++ b/java_gen/pre-written/src/main/java/org/openflow/exceptions/OFParseError.java
@@ -0,0 +1,22 @@
+package org.openflow.exceptions;
+
+public class OFParseError extends Exception {
+    private static final long serialVersionUID = 1L;
+
+    public OFParseError() {
+        super();
+    }
+
+    public OFParseError(final String message, final Throwable cause) {
+        super(message, cause);
+    }
+
+    public OFParseError(final String message) {
+        super(message);
+    }
+
+    public OFParseError(final Throwable cause) {
+        super(cause);
+    }
+
+}
diff --git a/java_gen/pre-written/src/main/java/org/openflow/exceptions/OFShortRead.java b/java_gen/pre-written/src/main/java/org/openflow/exceptions/OFShortRead.java
new file mode 100644
index 0000000..3007803
--- /dev/null
+++ b/java_gen/pre-written/src/main/java/org/openflow/exceptions/OFShortRead.java
@@ -0,0 +1,6 @@
+package org.openflow.exceptions;
+
+public class OFShortRead extends Exception {
+    private static final long serialVersionUID = 1L;
+
+}
diff --git a/java_gen/pre-written/src/main/java/org/openflow/exceptions/OFShortWrite.java b/java_gen/pre-written/src/main/java/org/openflow/exceptions/OFShortWrite.java
new file mode 100644
index 0000000..fb0ddea
--- /dev/null
+++ b/java_gen/pre-written/src/main/java/org/openflow/exceptions/OFShortWrite.java
@@ -0,0 +1,7 @@
+package org.openflow.exceptions;
+
+public class OFShortWrite extends Exception {
+
+    private static final long serialVersionUID = 1L;
+
+}
diff --git a/java_gen/pre-written/src/main/java/org/openflow/exceptions/OFUnsupported.java b/java_gen/pre-written/src/main/java/org/openflow/exceptions/OFUnsupported.java
new file mode 100644
index 0000000..14e96db
--- /dev/null
+++ b/java_gen/pre-written/src/main/java/org/openflow/exceptions/OFUnsupported.java
@@ -0,0 +1,7 @@
+package org.openflow.exceptions;
+
+public class OFUnsupported extends Exception {
+
+    private static final long serialVersionUID = 1L;
+
+}