Google Web Toolkit throws java.security.AccessControlException - google-app-engine

I'm trying to read a sqlite db from the server side code in my gwt project. It throws AccessControlException. I looked a lot on the web and all solutions seems to be disabling Google App Engine, but when I do this, I can't run my project. I'm new to GWT and I have no idea where it runs when Google App Engine is shut down. I look for possibly this two solutions: Any setting that Google App Engine is set to be able to read any file, or other engine that I run my application on. Thanks

The problem is that Google App Engine (GAE) does not support sqlite (I assume you are reading it using JDBC).
If your intention is to make a GWT project that will not be deployed on GAE, you should create the project disabling this feature from the very beginning, because afterwards its a nightmare as you are experiencing right now.
If your intention is to deploy in GAE, you must use the google's persistence mechanisms (JDO) to store your data. SqlLite is off the table here.

Related

Different App Engine Applications in Google Cloud

I'm looking at moving my application to google cloud and I'm having a hard time understanding how best to organize my project. It seems like you can only have one App Engine application per project with services available to support a microservices architecture and instances representing the App Engine instances created via auto scaling.
What is the correct way to build an App Engine for my API server and an App Engine for my Web Server? Do I need to have a project for each? I'm essentially trying to accomplish the following:
It is straightforward to have a single GAE project implement both your website and an API. You can even do this within a single service. You could put each in a separate service, and the advantage of that is that you can update one without updating the other. For small projects, a disadvantage is that two services are more expensive than one (though GAE is quite inexpensive overall).
For prod vs dev, you'll need to explain your requirements a little more, but here are some thoughts.
Each GAE service has multiple versions. You can deploy your production version to www.mycompany.com and deploy a dev version to dev-dot-myapp.appspot.com (that's the way GAE does URLs for versions of your app). Both of these versions will access the same datastore so you need to be careful with the dev version so that it doesn't mess up your prod implementation.
If you have a dev situation that is bleeding edge and shouldn't be able to access the datastore of your production app, then you would create a different GAE project for that.
Here is a way to visualize it:
Google Cloud Project A
GAE Project A
production www service
production API service (this could be combined with production www service)
dev www service
dev API service
Google Cloud Project B
GAE Project B
bleeding edge www service
bleeding edge API service
Best Practices:
Your Dev and Prod should be in separate projects for both security and billing purposes.
App Engine:
You can only have one App Engine per project. This will create a problem for you to use App Engine for both API Server and Web Server. In this case, I would not use App Engine at all and instead look at Containers on Compute Engine or go for Kubernetes.
Even a single node Kubernetes Cluster will shock you with its flexibility and power. Containers on Compute Engine still have a lot flexibility and power too. If you like the concepts of App Engine Flexible, then you might really like containers. The exception here is that App Engine makes some concepts brain dead simple where you have more work in configuration for Containers or Kubernetes.

Deploy non-web Java application

I have a relatively small Java app, which I'd like to move over to the Google App Engine. It runs in the console, with no user input needed after the initial startup. I researched a bit on how to deploy it, but all tutorials seem to focus on Java web apps, when I don't really need that. Is it possible to deploy my app if it's not a web app?
App Engine is probably the wrong GCP platform for you - you'd probably be better served just deploying your jar directly onto a Google Compute Engine node. GAE is pretty explicitly oriented around web applications and you'd need to do a bunch of configuration in order to have it work for your use case.
Does your non-web Java app handle web requests? If not, it seems difficult to imagine that you would be able to reach your deployed app and use it for any purpose, once deployed. Your Java app should be able to handle requests, to make deployment worthwhile, and the deployed app useful.
You may find out about how your app should handle requests by reading the How Requests are Handled documentation page.

Google Cloud Datastore requires app engine?

Im creating a Node.js website that probably won't have loads of traffic, and was looking into cheap solutions to host the site. Came across Google cloud services offering free usage for their services with limits. A f1-mirco is more than enough for my needs, but I will happily pay for some usage if it goes over by any chance.
I wanted to setup a linux centOS 7 on GCE (which I already did), and run my application and REST API on it. Now here comes the problem.
I tried to use Google's datastore service, but it sprung an app engine instance and without it datastore won't work.
Is datastore entirely relying on app engine to function?? In the docs, it said if you use any of the client API, it requires app engine. What can I do to not use the client api and query data then? Don't want to use the app engine at the moment or datastore is just not for me then?
Thanks for any help!
Some of the underlying infrastructure of Cloud Datastore and App Engine are still tied together for creation, etc. So while creating an Cloud Datastore database also defines an App Engine instance for the project, it doesn't require you to use it. You don't get charged for App Engine either, unless you decide to deploy an App using it.
You should be totally fine use the Google Cloud Node client library on the f1 micro instance.

Securing a deployed Roo/GWT application

I recently succeded in uploading a Roo/GWT project on Google App Engine.
But, how can I secure it from the Google App Engine application dashboard?
Is there a way to tell to GAE to put a Google Login Box at the start and set a list of authorized accounts?
Thank you very much,
Regards.
Just answered ~same q. here Adding an authentification system in a deployed Roo/Gwt project
This is in progress to be implemented for GWT 2.1/Roo 1.1.0. See this for more details https://jira.springsource.org/browse/ROO-1003
If you can't wait, check the Spring Security in Google App Engine article, at http://blog.springsource.com/2010/08/02/spring-security-in-google-app-engine/ That approach is not supported by Roo though (so once you change the generated code, it will be harder, but still possible, to continue using Roo)

Hosting/transferring a web site on Google App Engine

I have my website currently hosted on paid server, but i want to transfer it on GAE.
How can i do it? Can anyone please help me in this case.I'd appreciate your help.
Thanks:)
1) First you will have to adapt your website to the GAE framework (python with django or the new Java environment). You can test your work by downloading the SDK of GAE which offer a local server.
2) Then create an account on appengine.google.com and upload your application on something.appspot.com, test it.
3) If you have a domain name, create a google apps account on this domain, and finally bind this domain with your GAE website. Here is the Google doc.
If it is just a static website which does not need server side scripts or a database, then you might want to look into Google Sites instead of Appengine. You can find out more about Sites here: http://www.google.com/sites/help/intl/en/overview.html
If you do have some server side logic going on, you will need to convert it to either python or java and convert your relational database to Google's Data API which does not support the SQL your current database uses. You can read more about the APIs and what is supported with the Data API and tutorials at: http://code.google.com/appengine/
In response to sanorita's comment "Actually, it's generated html and not plain html. and google appengine is for static data... right?":
AppEngine can host static data, but that is far from its intent.
The purpose of AppEngine is to allow developers to easily deploy their dynamic applications on Google's infrastructure. In the end, assuming you have programmed your app in effective ways to handle scaling (basically just noting that writes to the database are expensive, and contention is the root of all evil) you can handle nearly any amount of traffic.

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