I checked the ApiKeyInitializer.java file (I had it locally on my computer). It looks like a valid java class :
/*
* Copyright 2012 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.android.gcm.demo.server;
import com.google.appengine.api.datastore.DatastoreService;
import com.google.appengine.api.datastore.DatastoreServiceFactory;
import com.google.appengine.api.datastore.Entity;
import com.google.appengine.api.datastore.EntityNotFoundException;
import com.google.appengine.api.datastore.Key;
import com.google.appengine.api.datastore.KeyFactory;
import java.util.logging.Logger;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
/**
* Context initializer that loads the API key from the App Engine datastore.
*/
public class ApiKeyInitializer implements ServletContextListener {
static final String ATTRIBUTE_ACCESS_KEY = "apiKey";
private static final String ENTITY_KIND = "Settings";
private static final String ENTITY_KEY = "MyKey";
private static final String ACCESS_KEY_FIELD = "ApiKey";
private final Logger logger = Logger.getLogger(getClass().getName());
public void contextInitialized(ServletContextEvent event) {
DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();
Key key = KeyFactory.createKey(ENTITY_KIND, ENTITY_KEY);
Entity entity;
try {
entity = datastore.get(key);
} catch (EntityNotFoundException e) {
entity = new Entity(key);
// NOTE: it's not possible to change entities in the local server, so
// it will be necessary to hardcode the API key below if you are running
// it locally.
entity.setProperty(ACCESS_KEY_FIELD,
"replace_this_text_by_your_Simple_API_Access_key");
datastore.put(entity);
logger.severe("Created fake key. Please go to App Engine admin "
+ "console, change its value to your API Key (the entity "
+ "type is '" + ENTITY_KIND + "' and its field to be changed is '"
+ ACCESS_KEY_FIELD + "'), then restart the server!");
}
String accessKey = (String) entity.getProperty(ACCESS_KEY_FIELD);
event.getServletContext().setAttribute(ATTRIBUTE_ACCESS_KEY, accessKey);
}
public void contextDestroyed(ServletContextEvent event) {
}
}
Perhaps you somehow deleted the contents of that file.