does any one knows how behind is the c# version of Solr from its java version? does any one suggest we use c# based instead of java based?
best
I guess you are referring to a C# client library for Solr. In fact, you don't have to worry if Solr is written in Java, there are a lot of different client libraries you can use to communicate with Solr without using java. You just need to install Solr on a Java servlet container like Tomcat, provide your xml configuration, basically the schema.xml and solrconfig.xml files. After that you can start using your favourite client library, written in C# for example, to communicate with Solr.
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is it possible to invoke function which is written in Java using WCF or any class application written in C# .net
Can it be possible by using webOrb..
i can't find enough information about Java to .Net remoting..
If you want to communicate between C# and Java you have a couple of options.
The cleanest: Build a service.
This assumes you have access to the source code of both your C# component and your Java component. In the case that you want to call a method within Java, you can build a service that allows a connection from your C# client, to your Java service, and the service then executes the desired functionality, and returns a value back to the C# client. Some easy ways to do this is by building a RESTful service or using Thrift. I recommend you choose a solution similar to this one.
The most complex: Corba
Corba is a standard defined to communicate amongst different computer languages. Most mature languages have support for it, but it is a bit unusual, and the use of it has declined in favor of building service. This also assumes access to both source codes.
You'd have to independently look for the information regarding how to use Corba on both Java and C#. I would really advice against this.
The dirtiest but quickest: Execute as process and parse output
I really do NOT recommend you to do it this way unless you really have no choice. This would entail executing a Java program from within C#. This is only a good choice when you have no other option, because all you have is an executable. If that were the case, you can use the Process class to execute the external program, sending it parameters, and then reading the output. See the example mentioned here:
How do I start a process from C#?
This has many downsides though, as you'll have to think of every exceptional cause, determine the output for those cases, and then determine how to parse that output. If the program has any level of complexity, before you know it, you'll end up with hard to maintain code.
Conclusion: Build a Service
That's probably your best bet. Build a service that exposes an API that the C# client can call on.
We are using JCOBridge package: it is able to create a bidirectional invocation of Java API from C# (.NET Core/6/Framework).
The templates available on Templates was our good starting point for the needs we had. We reach the goal in few lines of code.
UPDATE 2022: the JNet project on GitHub can be used as a starting point. Another project is KNet, hosted on GitHub and based on JNet, that is a gateway for Apache Kafka Java API.
I have a Java API in jar file with some dependencies from other jar files.
Is there any way to call a specific method from this API, like using PInvoke from .NET?
Here you go :) I've used it myself and was very please with the implementation.
IKVM: Using Java API's in .NET Applications
(1) If you just want some libraries
from Java.
(2.1) If you have access to
the code.
(2.2) Last resort,
dynamically load the Java into .Net
(interpreter)
I don't think it will be an easy task to interoperate .net and java. May be you could use sockets, and use them to send messages from one environment to another. It is just an idea, though.
EDIT:
I have found some libs that say they can do this:
http://www.jnbridge.com/
http://www.codeproject.com/KB/dotnet/Espresso.aspx
You can use CORBA to "call" java methods from .NET.
For .NET here you can find some CORBA libraries.
Java SDK includes CORBA capabilities so you don't have to download 3rd party libraries.
I have a pet project that is an online game, the entire game engine is written in C# and I would like to know if there is anyway I can call the functions of this existing assembly (.dll) from a solution built using Node.JS, Socket.IO, Express etc?
The game engine itself is pretty complete; tested and robust. I am hoping there is some neat way of exposing its functionality without too much overhead.
UPDATE:
To answer my own question a little..
I have ended building my own web socket server (based on the most current web socket protocol document). It is written in C# and compiled using Mono so that it can be hosted on a Linux box running mono and therefore (with a few tweaks) I can use my existing game engine.
UPDATE 2
A project that does exactly what I was originally looking for now exists - http://tjanczuk.github.io/edge/#/
UPDATE 3
Edge.js supporting node's last versions and .net core with a new edge-js package.
Support for Node.Js 6.x, 7.x, 8.x, 9.x, 10.x, 11.x Support for .NET
Core 1.0.1 - 2.x on Windows/Linux/macOS. Support for Mono runtime
4.8.x - 5.x.
Can be installed from https://www.npmjs.com/package/edge-js
Check out the edge.js project I started (http://tjanczuk.github.com/edge). It provides a mechanism for running .NET and node.js code in-process. Edge.js allows you to call .NET code from node.js and node.js code from .NET. It marshals data between .NET and node.js as well as reconciles the threading models between multi-threaded CLR and single threaded V8.
Using edge.js you can access islands of pre-existing .NET code from node.js, which seems to match your scenario.
I've been recently faced with the same challenge (requirement to call C# code from node.js javascript). I had 1000s of lines of complex C# code that I really didn't like to port to javascript.
I solved if as follows.
The relevant C# code is basically 1-2 classes in a DLL assembly
Defined a COM interface which is a subset of the C# class's interface and implemented that interface in the C# class. Thus, the DLL became an in-process COM server.
Implemented a node.js extension DLL that instantiates my C# COM class using standard Win32 COM API and routes method calls from node.js javascript to C# code using the COM interface.
This solves the problem if one only wants to make calls in one direction. I also had the requirement to make calls from C# to javascript. This is a lot harder. One has to:
Implement a COM object in the node.js extension DLL (ATL helps here)
Pass an interface reference of this COM object to C# code (COM Interop)
Route calls via the COM object to V8 objects in node.js
Maybe if I have some extra time, I might make an example project out of this.
If all you want to do is spin up a lightweight HTTP server while still programming with C# and .Net you should give Kayak a chance. It is a lightweight HTTP Server for C# and behaves kind of like node.js in that sense.
kayakhttp
Update:
If you are looking for a lightweight HTTP Server to handle web requests you have a couple alternatives today:
ServiceStack (recommended)
Microsoft WebAPI
NancyFx
To my knowledge all the above work on some version of Mono, so you can still host them across both Windows and Unix based systems.
.Net addons can be written, in short you write a regular native addon and add .Net calls via CLI/C++ calls to .Net dlls.
In practice you usually create a C# dll library which you then call from a CLI/C++ node addon project. There is a bit of delicacies such as making sure that the actual node add on definition file is compiled without CLR support so node can load it correctly.
You can check out: https://github.com/saary/node.net
for an example of how this can be achieved.
The following answer is out of date, but still helpful for understanding of Node.js from first release
Node.js is now also available natively for Windows at nodejs.org. No cygwin requirement or otherwise.
First of all, at the moment there's no native Windows port of Node.js, there's only a cygwin version (but I suspect you already knew that).
There was a node module floating around somewhere at the GitHubs that provided wrappers for calling into native libraries, but iirc, that only worked with .so libs.
Therefore, if you want to use a C# DLL, you will first have to write a native Node.js extension as the interface:
https://www.cloudkick.com/blog/2010/aug/23/writing-nodejs-native-extensions/
From that extension you have to load the DLL and wrap the calls from Node.js to the C# code, that means you have to write some low level C/C++ code and convert C# values to V8 stuff.
I only have experience with C++ and V8, it's a bit hard to get started since the code examples are a bit sparse, also wrapping C++ classes is not that trivial. But I did wrote small JS game engine kind of thing, that uses a C++ OpenGL backend, it's unfinished (and there are hardly any comments) but it might give you some ideas.
Note: There are some projects in the wild that provide somewhat automatic generation of wrappers to V8, but those are C++ only.
So to conclude, I think it will be quite adventurous getting the C# wrappers to work, but it should be possible.
Edge.js supporting node's last versions and .net core with a new edge-js package.
Support for Node.Js 6.x, 7.x, 8.x, 9.x, 10.x, 11.x Support for .NET
Core 1.0.1 - 2.x on Windows/Linux/macOS. Support for Mono runtime
4.8.x - 5.x.
Can be installed (npm i edge-js) from https://www.npmjs.com/package/edge-js
You might have some luck with this project, which is a port of Node.js to .NET. I haven't used it myself, but with a native .NET implementation you theoretically should be able to do what you need to.
You might also want to go the other direction and try to port (aka: recompile unless you're hooked deep into Windows) your C# game engine to Mono and see if you can then build wrappers off of that.
I know it's an old question, but wanted to throw in a current answer. With IIS 7.5 and .Net 4.x Websockets are supported, though use of the SignalR library will likely be the path of least resistance. It's similar to the socket.io library for NodeJS.
As to accessing .Net code via NodeJS, your best options are Edge.js, building a mixed native assembly with C/C++, exposing your .Net code either via a command line application (best to use pipes for input/output) or via a service (TCP or other).
I find Edge.js to be very limited, and not offer much over a piped console interface.. and feel that a service may be best for a more complex interface. At which point you may be best doing the rest of the project in .Net, unless you have an investment in NodeJS that supersedes said difficulties.
We've written a Java program which we are looking to use and interact with from C#. What are our options? Optimally it would be possible to compile the Java application as a library (.DLL) that we could reference from C# perhaps using P/Invoke. This, however, doesn't appear to be an option according to the first few searches online.
We opt to be able to use ASP.NET to built a search engine powered by the Java code, so if this opens up for any other options please let us know.
Sorry, you cannot call java code / classes Directly from C# code.
One way of doing this is to wrap up your java classes in a java Web Service and call classes indirectly through that web service interface in your C# code.
Another way is using
javareg.exe which exposes java classes as COM. You can find it at following location:
C:\Program Files\Microsoft VisualStudio\VIntDev98\bin\javareg.exe
Following posts might help as well
Calling Java Classes Directly from
.NET (uses runtime bridge)
Calling Java from Microsoft.NET
The simplest approach would probably be to publish the functionality of your java library as web services and add a web-reference from your asp.net application.
Java isn't meant to be embedded in another program, so you need a bridge. The most simple solution is to use a socket: Create a Java process which listens for commands on a socket. In the C#, send the commands to the socket and read the answers.
The main problem here is serialization but if you use XML, it's not such a big pain anymore. Try the built-in XML serialization (see this article) or custom frameworks like XStream or Simple.
It is certainly possible to wrap Java in a .dll, and has been a part of the core Java platform for over 10 years. JNI (Java Native Interface) has an interface for embedding a JVM in your code, meaning you can run Java classes using C-style linking. Note that this will require that you write a simple C wrapper, there are samples within:
http://java.sun.com/docs/books/jni/html/invoke.html#11202
As some of these other posts suggest, sometimes it's desirable to be less tightly coupled, so you may want to consider using another design. One option would be a simple database, where the Java application regularly polls for requests from the C# code. If you want tighter coupling, for things like call-backs, you can look at distributed interfaces.
I have a nightly executable that will run on a windows or linux server that will be downloading information from various web sources and one of those sources contains a JSON response. This executable will download the information and connect to a SQL server database to update the appropriate records.
I come from a C#, windows programming background so my natural inclination is to use the JSON.net libraries or create custom code to parse the JSON text using C#. But I'd really rather use the appropriate scripting language to take advantage of the eval() statement to process the JSON.
Does anyone have a suggestion for which scripting language and development environment that would be best suited for this kind of server process? It doesn't matter to me if it runs on the linux or windows server, I just want to use the best tool available.
The eval() technique only works within JavaScript, as JSON is valid JavaScript syntax. You might be able to use something like Rhino (Java), but otherwise every language you choose will require using a JSON library. Since you are most familiar with C# and .NET, it seems like the most logical choice if the target machine already has it available.
JSONsharp (.Net 2.0+) or JSON.net (.Net 3.5) are your friends here, as are others on JSON.org.
But beware the eval() statement in JavaScript - it executes the JSON, so if someone has put javascript in there, you may find yourself running code. Instead you would want to use something like JSON.parse.
Any scripting environment should be fine, and nearly all have decent JSON parsers built in.
Here's a Python example (requires Python 2.6 and up for the built-in json module, otherwise download simplejson):
import urllib2, json
response = urllib2.urlopen("http://example.net/url/for/json").read()
data = json.loads(response) # returns a native Python type, e.g. a dictionary
# your code here
process_and_update_db(data)
If you want to use .NET (may be easier to access your DB, for example), and want a good scripting language like Python, try IronPython. You can use download and use simplejson instead of json.