I have a rather big appengine application completely written in Java. I would need to obtain results from functions completely written in python (if possible 3.x) with numpy and similar packages.
What is the best way to do it?
I'm thinking in two options.
You can write an app-engine's python module (now called services) using default or Flexible Environment. Then your default module have access to this special module via HTTP requests, synchronously via URL Fetch API or async via Push Queue API, which can only be done via *.appspot.com URLs.
Here is the official docs about module communication uses ModuleService API which resolves module addresses to *.appspot.com addresses.
You can try to execute python code using PythonInterpreter class, but i not sure if the sandbox avoid to use it.
Related
I'm building a REST API with ASP.NET, which should ideally be able to use Java code. I've already managed to create a bridge between .NET and Java by using jni4net in a simple console application. This is absolutely necessary due the non-existing interoperability of .NET and Java.
Nevertheless I can't create a bridge in my ASP.NET project by using jni4net. Apparently this is a common error due the fact that .NET core 2.1 or later versions do not support the methods shown below. I am refering to this question: "Error in the webapp while connecting with JVM using jni4net from C#".
MissingMethodException: Method not found: 'System.Reflection.Emit.AssemblyBuilder System.AppDomain.DefineDynamicAssembly(System.Reflection.AssemblyName, System.Reflection.Emit.AssemblyBuilderAccess)'.
Note that I'm using .NET core 3.1 for my ASP.NET project and jni4net 0.8.8.0. Anyways I'm would change my .NET version if needed. My current implementation in Program.cs looks like this:
using net.sf.jni4net;
public class Program
{
public static void Main(string[] args)
{
var setup = new BridgeSetup();
setup.Verbose = true;
Bridge.CreateJVM(setup); // Error is thrown here
}
}
Does anybody know if there is a way to bypass this error OR how to use Java code in an ASP.NET project? I highly appreciate any help or suggestion, sheers!
An API is a medium that recieves requests from client, processes those requests inside and responds back to the client.
You can probably do what you want to do by creating an API on .NET Core and consume that API in your Java project.
In the simplest way, you can create an API endpoint in your .NET project's controller and send a request to that api on your Java application using the target URL of your API endpoint.
The response from your API is going to be in JSON format.
Please note that you can consume an API regardless of the language since the communication between your application and your API is going to be via HTTP requests and JSON responses.
Some useful video links to start with:
How to build a restful API in .NET Core 3.1 https://www.youtube.com/watch?v=fmvcAzHpsk8&t=11447s&ab_channel=LesJackson
How to consume an API in Java application https://www.youtube.com/watch?v=Fry7waUIJiY&ab_channel=PrakashShindalkar
I also would like to clarify that HTTP is just a a protocol. You can probably achieve what you want with other communication protocols as well but this one is fairly more popular and suitable for your needs.
As far as I know jni4net is not compatible with .NET Core. It's for .NET Framework.
This is absolutely necessary due the non-existing interoperability of .NET and Java.
I don't know the circumstances but it shouldn't be a necessity. Just build a service that exposes API to C# code. Voila you have a bridge. Or you can use CORBA however it's so complex it doesn't worth at all imo.
As I have understood we use Web services(Rest/Soap) so that a piece of code with some functionality written in one language(say Java) can be used by other programmer no matter the language(say Python) he is developing the application over the internet.
One of the projects I came across uses EWS web services to create,delete appointments on our Outlook 365. The application is developed in Java and a JAVA EWSAPI.jar file is included in the library path(which contains class files like appointment.class,Meeting.class etc) to connect to EWS server and create meetings .
My confusion is suppose we were developing the application in Python, so for that do we have another API (say EWSPython.pythonextension). So then how developing a web service helped us.
I understand API defines the set the methods available and how can they be called with argument.
Please clear my doubts.
I think that you have misunderstood the aim of webservices. We need webservices to make their calls (clients) a platform independent interface which means that once you have created your webservice using any technology (java for your case here) now anyone can call this service by creating a client using any language like python, C#, C++, Ruby, ........... in that case a service which was built by Java will be consumed or called by an application or client created using python and vice versa.
JAVA EWSAPI.jar file is a API Client Library.
What is a client library?
A client library, sometimes called a helper library, is a set of code that application developers can add to their development projects. It provides chunks of code that do the basic things an application needs to do in order to interact with the API. For example, a client library may:
Provide boiler-plate code needed to create an HTTP request and to process the HTTP response from the API.
Include classes that correspond with the elements or data types that the API expects. For example, a Java client library can return native Java objects in the response from the API.
Handle user authentication and authorisation.
How is that useful?
Looking at the developer who’s using the API: With a REST API or any web service API, the developer could be using any of a number of programming languages to make the API calls.
Wouldn’t it be great if we could give them some code in their own language, to help them get started with the API? That’s what a client library does. It helps to reduce the amount of code the application developers have to write, and ensures they’re using the API in the best supported manner.
For more information:
https://ffeathers.wordpress.com/2015/10/25/what-is-an-api-client-library/
Ok, this is the scenario: I've developed a webapp running Java at backend, everything is working pretty well, but now I have to integrate a PHP module (boss requirement) within the whole system.
So, I need to know if both backends can co-exist in a single application and how can I accomplish that.
Yes, you can do it using GwtPhp.
Unlike most of the other frameworks, GwtPHP is a framework for both client and server part. Server part uses PHP 5 - the most used web scripting language today.
It does not sound as if your boss is being reasonable!
There are some possibilities, though:
You could have the server-side entirely in PHP. Obviously you'd still have Java for the client-side because GWT requires it, but GWT can communicate via HTTP to any type of server using XML. You just can't use GWT's RMI-like interface if it's not a Java server.
Alternatively, you could have a separate PHP layer in your app, and the server-side Java itself can call it using HTTP.
Finally, (and more difficult, and experimental) there is a project to allow PHP to run in a Servlet Container, which may give you the ability to mix Java and php: see http://www.php.net/manual/en/intro.java.php
Two things spring to mind.
1) If the PHP app supports JSONP you could run it on a separate server and interact with it that way.
2) Stick the servlet container behind apache and proxy to the servlet container using something like the AJP connector. This would mean that apache forwards the GWT requests to tomcat/jetty whatever and serves the PHP itself.
In a web application I am developing, I am using a third party Java library (JPL) that uses JNI to connect to an external application: a Prolog engine.
For the nature of my problem, I need to have one Prolog engine per http session. But as far as I know the library I am using only let me work with one Prolog engine per java VM.
In order to solve this issue I came up with the idea of trying to configure JBoss to launch a new process (instead of just a new thread) per each http session, a bit like CGI where normally one process is started per http request.
In this way, certain servlets could use the required JNI based library without having to worry about synchronization issues in its side, since as I expect (and hope not be wrong about that), each of them will have an independent Prolog engine with different state (e.g., different asserted Prolog facts).
Is possible to configure JBoss (or other servlet container) in this way? Any feedback or pointer will be highly appreciated!.
To my knowledge this is not possible. However looking at the documentation http://www.swi-prolog.org/packages/jpl/java_api/high-level_interface.html#Multi-Threaded%20Queries the only problem seems to be that you can have only one open query per VM.
I am new to wavemaker but the development with it seems to be straightforward.
I tried to invoke some calls to the amazon Product Advertising API (with SOAP) but it didn't work. The problem seems to be that every call has to be signed (see e.g. here: http://www.mularien.com/blog/2009/08/13/tutorial-amazon-soap-product-advertising...)
This seems to render the whole endeavor really burdensome. Has anyone done this and successfully included this API into a wavemaker application? (examples with REST are of course also welcome).
Thank you very much!
The signing requirement does really complicate the whole thing.
Instead of importing the WSDL into WaveMaker and using the WaveMaker generated client, you can use the mularien example code as a java service.
Generate the client following the example and add the jars and classes to your project classpath.
Add a java service to your WaveMaker project.
In the java service, any/all public methods are exposed to the browser client.
So if you com.mularien.amazon.AmazonProductSearch is your java service class, getAmazonInfo(String) would be callable by the client.
Alternatively, instead of directly exposing the AmazonProductSearch functions, use your java service class as a manager. For example, you might want to return only a sub set of Item_type3. A wrapper/manager class as a your project service between the client and AmazonProductSearch can provide that.