Hi R,
Yes I tried to save persistence objects using sth like this in the
servlet:
Student newStudent = new Student(googleID, fullName,
matricNum, email, team);
PersistenceManager pm = PMF.get().getPersistenceManager();
try {
pm.makePersistent(newStudent);
} finally {
pm.close();
}
I tried to retrieve data by writing the following in a redirected jsp
webpage:
<body>
<p>You have been successfully register as the following: </p>
<% PersistenceManager pm = PMF.get().getPersistenceManager();
String query = "select from " + Student.class.getName();
List<Student> students = (List<Student>)
pm.newQuery(query).execute();
for (Student stu: students) {
%>
<table>
<tr><td>Name: </td><td> <%= stu.getName() %> </td></tr>
<tr><td>Matric: </td><td> <%= stu.getMatric() %> </td></tr>
<%
}
if (students.size()==0) System.out.println("no storage at
all");
%>
</table>
</body>
Nothing shows there and a message "no storage at all" is printed out,
showing that no Student instance has been stored.
Meanwhile, there's no error message except "local_db.bin does not
exist".
I use almost the same codes for the google demo project and there was
no problem storing "Greetings" in "guestbook". But in my own project
there's problem in storing.
regards,
Erencie
On Jul 20, 12:13 am, Ronmell Fuentes <ringe...@gmail.com> wrote:
> Hello Erencie.
>
> have you tried to save persistence objects in data store? and have you tried
> to retrieve all data saved in your data store?
> does it show any error?
>
> are you using something like JUnit or something besides the code shown in
> google tutorials?
>
> Rgds.
>
> R
>
> 2010/7/19 Erencie <xiaoni....@gmail.com>
>
>
>
> > I use Google app Engine plugin for Eclipse and managed to make the
> > "guestbook" demo run successfuly. When I create my own app by
> > following the code pattern of "guestbook", sth weird happens:
>
> > Jul 19, 2010 6:08:46 AM
> > com.google.appengine.api.datastore.dev.LocalDatastoreService load
> > INFO: The backing store, D:\Eclipse workspace\TeammateV0.0\war\WEB-INF
> > \appengine-generated\local_db.bin, does not exist. It will be created.
>
> > I noticed that in /war/WEB-INF/appengine-generated folder, there is
> > only "datastore-indexes-auto.xml", but no "local_db.bin" file exists,
> > unlike the case in the demo guestbook project.
>
> > And I find that I cannot store anything persistent objects, even
> > though I follow the correct codes in tutorials. However, the whole
> > thing runs without any errors.
>
> > I tried diff configurations in the few xml files, and tried using
> > transactions as well. I did also closed the persistentFactory. But
> > nothing changes.
>
> > Can anyone help me?Thanks a lot.
>
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