Is it possible to write a user interface in Java for an application written in C#?
I am working on a user interface of a project that is written in C#, but I have no experience with C# and I am an avid Java user. Is it possible to build the user interface in Java using Java's Swing and AWT libraries that operates an application primarily written in C#.
If this sounds like a really stupid question, I apologize in advance.
You might be able to leverage some of the interoperability features that are integrated into Mono 2.0
http://www.mono-project.com/Main_Page
JNBridge is another possible interoperability solution:
http://www.jnbridge.com/
However, a more optimal approach might be to expose your .NET code as Services - and then access them from the Java client (or through a light-weight ESB).
Of course, time, budget, resources are constraints you'll have to consider.
In addition to http://www.jnbridge.com (proprietary)
you can try http://www.janetdev.org, - open source implementation of a Java 5 SE JDK environment for the .NET platform. Currently it supports .Net 3.5 only (not Mono).
We did this recently and went the route of using a low level socket connection, but pushing xml through it. C# was the server side, and we used the Microsoft 'xsd' tool to generate the XSD schema for the objects and then used JAXB on the java side to generate java code to parse and hold the same objects.
As Barry mentions most of the work/problems was around the socket connection - but that depends on how comfortable you are with that.
Also, for a solution that cross-compiles your java to run in the CLR: http://www.ikvm.net/
I am author of jni4net, open source interprocess bridge between JVM and CLR. It's build on top of JNI and PInvoke. No C/C++ code needed. I hope it will help you.
Related
I am creating a source code editor for Java using C# in .NET 4. I need to know how I can interact with the jre to compile the java code on my application editor interface from .net. I wish to display the user any errors on the code as well. Any ideas on how to accomplish this will be greatly appreciated.
Note that the JRE is the runtime, and as such doesn't come with the compiler. You will require the JDK to compile.
I think the simplest solution is to spawn off an instance of javac from within your .Net application. Perhaps a preferable solution (however) would be to write your app in Java itself, and you can then make use of the Java compiler API directly within your app.
Perhaps the most natural interoperability method is to run the Java code in a JVM, the .NET code in a CLR, and use a runtime bridge to manage the communications between them. In this scenario, the .NET code calls .NET classes and objects that act as proxies for the Java classes and objects. The proxies manage the communication; the calling .NET classes aren't even aware that they're ultimately calling Java classes. A runtime bridge provides interoperability for a wide variety of architectures, because the Java code and the .NET code can be on different machines, the Java code can run in a standalone JVM or in a Java EE application server, and the solution provides interoperability for any JDK version. As with bytecode translation solutions, you need only the Java bytecodes, not the source.
The code for this article uses JNBridgePro from JNBridge.
I have a game server which is made in Java. I want to make a plugin system that loads a .NET DLL and calls events / functions inside that DLL, then inside those I'll have to call functions in the game server (Java). The only part that is giving me trouble at the moment is how to interface java and a .NET dll.
I've been searching and found some things but they were all based on products and I want to make my own interface for that. Ah, not to mention it needs to have high performance, the code will be called a lot of times in a second if it has to. Could someone point or give-me ideas how could I work this out?
EDIT:
To make it more explicit:
Game Server (Java application) calls a function in .NET dll
The .NET function just called by java, calls multiple functions from Game Server (Java Application).
Take a look at jni4net if you're targeting Windows. It's an alpha quality release, but Robocode already uses it to run .NET robots inside the Java runtime.
Another option is to use a high-performance messaging approach. You'll need a second process - likely a .NET plug-in host. That process then exchanges messages with the main Java game process. Messaging libraries like 0MQ are pretty darn fast but may not be fast enough for what you have in mind. In addition, you'll have to create a lot of message plumbing which may be cost/time prohibitive.
Try using iKVM:
IKVM.NET is an implementation of Java for Mono and the Microsoft .NET
Framework. It includes the following components:
A Java Virtual Machine implemented in .NET
A .NET implementation of the Java class libraries Tools that enable Java and .NET
interoperability
http://www.ikvm.net/
If you only have a few methods you are calling you might just use JNI and do it yourself instead of a 3rd Party tool (though I admit I don't know the details of jni4net). Just a word of caution, the project I'm on had to do a similar thing (C# -> C/C++ -> Java via JNI) and we had nothing but problems with it. Problems mainly because the java api didn't have any good documentation so that might have been part of it. If at all possible try to keep it to one language but if that is not possible, make sure you do lots of error checking. When the app crashes, it is very hard to find the problem (unless you own both the java and C# sutff). Just my $0.02...
I have a solution with 2 projects:
a c++ main project
a c# project (display simulator)
Today these 2 apps share data using a loopback TCP client/server connection, but that's not very optimal (timing issues..).
I was wondering if there was a way to access the c# data from the c++ project directly and vice versa? (It seems to be possible with 2 c# projects..)
If it's not possible, what's the best way to implement this with shared memory?
thanks!
Michael
EDIT: thanks for the answers. The 2 projects used to be independant solutions and are both executables - I'm actually trying to merge the 2 into 1 solution / executable.
For info: The c++ app is a PC version of an embedded app - the c# app is a lcd/HMI simulator.
Converting the C++ project to a C++/CLI project might be the easiest way to go. Note however that some code doesn't play well with C++/CLI (we've had problems using libraries that use boost::thread in a managed executable).
You can use COM Interop or Platform Invoke to access native code in C#.
If that's not what you're asking for, please elaborate.
Named Pipes?
For interprocess communication via named pipes you can check out the .NET 3.5 feature
http://msdn.microsoft.com/en-us/library/system.io.pipes.aspx for the C# side. From the C++ side, I assume you know the equivalent :).
There are two ways I know of to get direct access to memory between c++ and c# without the overhead of marshaling/demarshaling and com. If it is required to keep the c++ part of your code native then the only way I know to achieve this is to host the clr from your c++ application. A relatively complicated undertaking. Google "hosting the common language runtime". Then you can load your c# code as an assembly, call into the c# code and provide a common shared memory style interface. Although you will have to write all of the shared memory support yourself as I have found no direct support for shared memory in c#/.net.
The other way is to compile your c++ code with common language runtime support. This is by far easier and will allow you all the power and glory of c++ while allowing access to clr based data types, and the ability to call back and forth between your c++ and c# code. See "Language Features for Targeting the CLR" in your VS2008 documentation. pin_ptr will become your close friend and ally in this process.
I have an application in C# that currently authenticates to LDAP. We want to extend functionality to support IBM's Tivoli Access Manager, which is comprised of a Policy Server, and an LDAP server (and other modules as well). Unfortunately authenticating with the LDAP server for our customer is not acceptable, thus we must bind with the policy server instead.
The TAM's Policy Server has 2 APIs for authentication, one in Java, and one in C
My question: What is the better language for C# to interop, C or Java?
Keeping in mind: maintainability, and cost of development.
Thanks everyone in Advance.
Seems to me that C is the easier language for C# to inter-operate with, as there's a native interface in .NET to allow "unsafe" access. To communicate with Java, you have to go though JNI to get into Java, or use J#, or otherwise jump through hoops to communicate from C# to Java and back again.
I've not done any C# to Java communication (except across a socket or across Web Services), but I was on a team that used JNI to communicate from Java to COM via C++ code. We ended up having to throw away the JNI solution as too unwieldy. We rewrote the C++ component in C# and used a nailed-up socket for communication between the two components. This worked fabulously.
From this experience, if you are already using C#, then I would use the C API from C#. This is easy to do.
I've had good success with Managed C++/CLI for interfacing with C/C++ in the past, can't speak much on interfacing with java.
Also if you are going for straight C you can export the function calls directly to C#.
I would think that the API you are interfacing is nothing but an API. One front-end is Java, and the other is C, but you probably aren't interacting with Java code, probably just C.
That said, I suppose it would be whichever interface seems simpler. I'm guessing that C is, but if there is some great Java binding software that lets C# access Java libraries easily, it might be better.
Chances are they both link to C code right beneath the API.
I like Eddie's answer, but I would temper it with this observation - it depends on the skill set you ave in house. If you;'ve got a bunch of Java pros, then it makes sense to use Java. If you have a bunch of C-programmers, then the chouice is obvious.
One other comment though : are you sure TAM doesn't do .NET?
You shouldn't need to do any bridge between C# and C or Java. As Cheeso referenced, TAM has had a supported .NET API for a while now -- see here for information.
I am author of jni4net, open source intraprocess bridge between JVM and CLR. It's build on top of JNI and PInvoke.
Does anyone have a good solution for integrating some C# code into a java application?
The code is small, so I could re-write in java, but I would rather reuse the code if possible. Don't repeat yourself, etc.
Also, I know I can expose the C# as a web service or whatever, but it has some security/encryption stuff in there, so I would rather keep it tightly integrated if possible.
Edit: It's going to be on a server-based app, so "downloading" another runtime is irrelevant.
You would use the Java Native Interface to call your C# code compiled into a DLL.
If its a small amount of C#, it would be much easier to port it to Java. If its a lot, this might be a good way to do it.
Here is a highlevel overview of it:
http://en.wikipedia.org/wiki/Java_Native_Interface
Your other option would be to create a COM assembly from the C# code and use J-Interop to invoke it.
http://sourceforge.net/projects/j-interop/
I am author of jni4net, open source intraprocess bridge between JVM and CLR. It's build on top of JNI and PInvoke. No C/C++ code needed. I hope it will help you.
If it's short, I think you're better off re-writing the code in java. Downloading one 50Mb runtime is bad enough.
There is an IL to Java Bytecode compiler GrassHopper which may be of use to you. I've never tried it though.
I'd look at rewriting your code in Java though
EDIT: Note that Grasshopper seems to be no longer available.
We used JNBridge for this, and it worked great. It handles Java->.NET and vice versa, all in-proc.
If you do not want to rewrite hadle it as an Inter-process communication and choose one of following:
Named pipes
Sockets
SOAP
I would rewrite it if it's not too much trouble.
The web service would work, but it seems like that would be a lot of overhead just to reuse a little code.
http://www.infoq.com/articles/in-process-java-net-integration suggests running CLR and JVM in the same process space and passing calls back and forth. It sounds very efficient. I'm going to give it a try and integrate it into Jace if it works well.
If it is a piece of code that is exposable as a command line utility, I just make the other host language use a system call to execute the utility.
If your C# app needs to call Java, compile a special Java main that takes appropriate command line args and returns text output.
It the oldest, simplest method.
You can call your c# classes (compiled in a dll) via a bridging library, various libraries are available, every one with his characteristics. JNBridge generate proxy classes that you can call to manage the code in java classes. JCOBridge let you load your c# classes and use it from java using the invoke mechanism, also javonet let you import java classes and call java code using the invoke mechanism. All the explored solutions are commercial solutions that let you call java code from .NET and vice-versa with graphical user interface integration and other amenities.
Links:
jnbridge java-.NET bridge Developer and Deployment license schema with 30 day free trial
jcobridge java-.NET bridge Developer and Deployment license schema with unlimited Trial
javonet java-.NET bridge Research and Professional license schema with 30-day unlimited Trial after sign-up