2 files changed, 94 insertions, 9 deletions
diff --git a/src/com/vaadin/data/util/MethodProperty.java b/src/com/vaadin/data/util/MethodProperty.java
index 87915bda88..5b15b66cd5 100644
--- a/src/com/vaadin/data/util/MethodProperty.java
+++ b/src/com/vaadin/data/util/MethodProperty.java
@@ -11,6 +11,7 @@ import java.lang.reflect.Method;
 import java.util.LinkedList;
 
 import com.vaadin.data.Property;
+import com.vaadin.util.SerializerHelper;
 
 /**
  * <p>
@@ -78,7 +79,7 @@ public class MethodProperty implements Property, Property.ValueChangeNotifier,
     /**
      * Type of the property.
      */
-    private Class type;
+    private transient Class<?> type;
 
     /**
      * List of listeners who are interested in the read-only status changes of
@@ -95,20 +96,25 @@ public class MethodProperty implements Property, Property.ValueChangeNotifier,
     /* Special serialization to handle method references */
     private void writeObject(java.io.ObjectOutputStream out) throws IOException {
         out.defaultWriteObject();
+        SerializerHelper.writeClass(out, type);
         out.writeObject(instance);
         out.writeObject(setArgs);
         out.writeObject(getArgs);
         if (setMethod != null) {
             out.writeObject(setMethod.getName());
-            out.writeObject(setMethod.getParameterTypes());
+            SerializerHelper
+                    .writeClassArray(out, setMethod.getParameterTypes());
         } else {
-            out.writeObject("");
+            out.writeObject(null);
+            out.writeObject(null);
         }
         if (getMethod != null) {
             out.writeObject(getMethod.getName());
-            out.writeObject(getMethod.getParameterTypes());
+            SerializerHelper
+                    .writeClassArray(out, getMethod.getParameterTypes());
         } else {
-            out.writeObject("");
+            out.writeObject(null);
+            out.writeObject(null);
         }
     };
 
@@ -117,20 +123,21 @@ public class MethodProperty implements Property, Property.ValueChangeNotifier,
             ClassNotFoundException {
         in.defaultReadObject();
         try {
+            type = SerializerHelper.readClass(in);
             instance = in.readObject();
             setArgs = (Object[]) in.readObject();
             getArgs = (Object[]) in.readObject();
             String name = (String) in.readObject();
-            if (name != null && !name.equals("")) {
-                Class<?>[] paramTypes = (Class<?>[]) in.readObject();
+            Class<?>[] paramTypes = SerializerHelper.readClassArray(in);
+            if (name != null) {
                 setMethod = instance.getClass().getMethod(name, paramTypes);
             } else {
                 setMethod = null;
             }
 
             name = (String) in.readObject();
-            if (name != null && !name.equals("")) {
-                Class<?>[] paramTypes = (Class<?>[]) in.readObject();
+            paramTypes = SerializerHelper.readClassArray(in);
+            if (name != null) {
                 getMethod = instance.getClass().getMethod(name, paramTypes);
             } else {
                 getMethod = null;
diff --git a/src/com/vaadin/util/SerializerHelper.java b/src/com/vaadin/util/SerializerHelper.java
new file mode 100644
index 0000000000..fe9eb28918
--- /dev/null
+++ b/src/com/vaadin/util/SerializerHelper.java
@@ -0,0 +1,78 @@
+package com.vaadin.util;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+
+/**
+ * Helper class for performing serialization. Most of the methods are here are
+ * workarounds for problems in Google App Engine.
+ * 
+ */
+public class SerializerHelper {
+
+    public static void writeClass(ObjectOutputStream out, Class<?> cls)
+            throws IOException {
+        if (cls == null) {
+            out.writeObject(null);
+        } else {
+            out.writeObject(cls.getName());
+        }
+
+    }
+
+    public static void writeClassArray(ObjectOutputStream out,
+            Class<?>[] classes) throws IOException {
+        if (classes == null) {
+            out.writeObject(null);
+        } else {
+            String[] classNames = new String[classes.length];
+            for (int i = 0; i < classes.length; i++) {
+                classNames[i] = classes[i].getName();
+            }
+            out.writeObject(classNames);
+        }
+    }
+
+    public static Class<?>[] readClassArray(ObjectInputStream in)
+            throws ClassNotFoundException, IOException {
+        String[] classNames = (String[]) in.readObject();
+        if (classNames == null) {
+            return null;
+        }
+        Class<?>[] classes = new Class<?>[classNames.length];
+        for (int i = 0; i < classNames.length; i++) {
+            classes[i] = resolveClass(classNames[i]);
+        }
+
+        return classes;
+    }
+
+    private static Class<?>[] primitiveClasses = new Class<?>[] { byte.class,
+            short.class, int.class, long.class, float.class, double.class,
+            boolean.class, char.class };
+
+    public static Class<?> resolveClass(String className)
+            throws ClassNotFoundException {
+        for (Class<?> c : primitiveClasses) {
+            if (className.equals(c.getName())) {
+                return c;
+            }
+        }
+
+        return Class.forName(className);
+    }
+
+    public static Class<?> readClass(ObjectInputStream in) throws IOException,
+            ClassNotFoundException {
+        String className = (String) in.readObject();
+        if (className == null) {
+            return null;
+        } else {
+            return resolveClass(className);
+
+        }
+
+    }
+
+}