Wednesday, July 30, 2014

Error: Unable to find class *_FieldSerializer


I have some problems executing GWT Tests. I need to store an object (called DatabaseConnection) in my test. I have some input fields consisting of a list box, which is filled with all of these objects, which are currently stored in the database. So I have to store the object first, to test the input fields afterwards.

I have serveral tests, which needs to store a DatabaseConnection. If I execute each of these alone, everything works fine. But when I execute all my GWT test, I get the following error messeage, when I try to save the object:

java.lang.RuntimeException: Unable to find class DatabaseConnection_FieldSerializer

It seems to me, that the error comes before the object is actually stored.
My Test looks this:

public void test() {

DatabaseConnection dbConnection = new DatabaseConnection();
TestHelper.storeDatabaseConnection(dbConnection, new AsyncCallback<Long>() {
public void onFailure(Throwable caught) {
// Here the test fails!
public void onSuccess(Long id) {

Timer timer = new Timer() {
public void run() {
// create a input field and do some validataion


// Waiting for asynchronous calls to finish.


My DatabaseConnection implements Serializable and the TestHelper executes methods implemented in a RemoteServiceServlet.

Does anyone know why my test are depending on each other? I am clearing my test database before and after each test.

Thanks for your help!

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