I am not sure exactly what I am asking....The guys that do the software development for the company I work for write everything in VB. I am currently the Web developer for this company and I specialize in Flex apps. I am thinking about expanding into their area. But I do not want to do VB, I don't mean to bash on VB but the coding syntax is not for me. So I am wondering if Java can integrate with VB? Also not sure if it matters but I think everything they do is procedural, and I will be doing OOP.
Thanks.
There are lots of integration opportunities, but before examining them, if I were you I would re-examine the question itself.
It should be exceptional to introduce a new language into an established project. The desires or aesthetic preference or skillset of a single developer is not a good enough justification to do so. Introducing a new language into a project should be a strategic decision for the project, not a backhanded one.
If you do choose to expand the core languages used to develop the system,
COM interop
is possible with JACOB. I believe IBM has a bridge as well.(Check alphaworks)
Java-.NET bridging
is possible via JNBridge and other bridges. This makes sense only if VB.NET is in use.
SOAP, XML document exchange, REST
suitable over a services boundary. It requires TCP or HTTP or some network protocol.
common data stores
can serve as a rendezvous point. Both Java and VB can read and update data in SQL Server, Oracle, MSMQ, MQSeries, and so on. Even a filesystem can be an integration point.
Think of data format as related to, but ideally independent of, the integration mechanism. What I mean is: You can use an XML document for integration, whether it is stored in a database, or sent over a REST interface, or stored in a filesystem, or put/get on a queue. You can use a comma-separated file over any of those mechanisms as well.
Potentially they could expose a service layer via soap or something simpler? Also you could always work against the same database with different languages however unless most of the logic is in stored procedures (not necessarily recommending this approach) then you end up with repeated code.
Not really. Java uses CORBA for interop, and VB uses COM for interop. You may be able to make a bridge using JNI, but I understand that can be quite the pain.
I haven't done this by I believe you have the following options:
Use the Java-COM bridge, as VB uses COM. This library was already mentioned here several times
If you are using VB.net, you probably use hessian, As it has both Java and C# implementations.
You could bridge the two using a C/C++ adapter to map JNI calls with COM. But that would be horrible. I hope there is a better solution, but my understanding is that it is pretty hard to integrate .NET code and Java as both vendors (Sun and Microsoft) don't have any incentive to streamline that kind of development.
Related
I have applications that have been written in Java, .NET and C++. They all use a common database.
Each app has it's own way of accessing the database, and so things are quite inconsistent.
I was thinking of writing a Data Access Layer using a ORM and having all applications use that.
The question is how to implement this ORM Data Access Layer:
Make a Java package using Hibernate;
use the Java package from the .NET and C++ apps
Make a .NET class library using Entity Framework;use the class library from the Java apps
In either case, is it easy to access the package/class library from the other platform? Any suggestions on the path to take?
Is communicating via XML between the two platforms the best way?
Ps. I have already seen this question, but I think my question is a super-set of that one.
Ps. Making a web-service is an option, but I would prefer not to write/use a web-service.
iKVM
This will allow you to share code between .NET and Java. I like most sane people in the world prefer to write data access bits in .NET, but if you've got existing code in Java you want to make available for .NET services this is available
http://www.ikvm.net/
RESTful Web Service++
This is the most sane and obviously the quickest way to get up and running. Again, you could use something like Jersey, ASP.NET MVC, NancyFx or whatever REST application server you wanted to get up and running.
I would recommend you use NancyFx and ServiceStack.Text. These are two very simple very pure implementations and are extremely fast, which is what you want if you're using it as a unified DAL on top of your database.
Nancy: https://github.com/NancyFx/Nancy/
ServiceStack.Text: https://github.com/ServiceStack/ServiceStack.Text
Jersey: http://jersey.java.net/
ZOMG T3h H0rror - COM+ / DCOM
This is actually a viable possibility if you can't use RESTful web services, and also assuming you're exclusively on Windows. This will also be the most troublesome depending on how insane your requirements are. That being said, I've seen this done before and seen it work quite well especially when you have legacy C/C++ components living inside different segments if your infrastructure.
Is communicating via XML between the two platforms the best way?
This will have a performance issue - but will provide a unified data layer in a language independent maner. You can consider the open source WSO2 Data Services Server, if you select to go ahead with this approach...
Thanks...
It sounds a bit like the database can be thought of as a service that your various apps consume to different extents.
What about writing a web service layer to wrap all access operations to and service-enable the database? You could use ORM in that layer and have all of your applications interact with the web service wrapper. If you can deploy it on the same server as the database you won't get much extra network overhead.
I think this would be a decent cross platform approach where you don't have to depend on libraries across platform boundaries, and you've provided a standard way of talking to the DB for all current/future apps.
Well, I've taken help of Google, Stackoverflow and whatever else I could find, did as much as I could, but it seems that I am unable to find out an exact answer! I have multiple queries, and I would love to have answers from the database-people as well as from the programmers and framework users.
From the programming languages, I know C/C++, Java and Python. I have undertaken a CMS project that would require frequent C's & R's of the CRUD. The project would have 50k users atleast. The head-to-toe of the project has been all figured out, and now I need to code it and make it live online.
Well, I want to use Neo4j as my database as its data representation model (nodes and relationships) is closest to the real project model. Now, neo4j has bindings for various languages, and one of them is Python (whose python bindings are very oldish, the jpype hasn't been updated since ages). I am thinking of going for some Java based framework, but then I leave this idea as I personally haven't heard much of java frameworks. But one of my partner tells me to go for Zend (PHP) as it has some kind of functionality that lets us execute Java code. Won't this slow the code? I mean executing one language's code in another language...
So, it all comes to this:
1) Database: I would want to go for Neo4j. But does it goes well off when the scalability factor kicks in? (From what I could gather from google, there are no scalability issues).
2) What framework to use in case of Neo4j? I would require a framework that is able to handle tonnes of requests and large data as the users of the project would be Creating and Reading data a lot.
P.S.: I know it is a long question, but couldn't jot it down in lesser words!
I can't speak about the scalability or suitability of Neo4J for your particular project.
However, I'd strongly advise you against trying to mix and match languages like Java and PHP. It's so much easier to stick to the best one for your particular task. I'd also strongly advise you against using JNI for anything unless you have no other option. Java is fast enough that you should almost never need JNI for performance.
That said, it's OK to run Neo4j in its "full server" mode and then have your PHP or Python application access it using some driver over the network. I just wouldn't recommend making an ugly hybrid of PHP and Java at your application layer.
Some decent Java frameworks you could check out include:
Spring
Google Guice with Sitebricks
Apache Struts 2
They're pretty standard in the industry and there are tons of good resources available on all of them.
In regards to the mini-question about language interoperability, Java provides the JNI interface, which allows the JVM and user code to make calls into other languages and vice versa. When the native code (e.g. C code called by Java, or Java called from C) runs, it is actually running in its natural environment, so there's no performance loss in terms of actual execution.
Neo4j as a standalone server has also REST API: http://docs.neo4j.org/chunked/milestone/rest-api.html, if you can embedded your requests in single REST queries, there is no need to use native embedded neo4j. If there is no need to use the embedded neo4j, you can take any language of your choice.
Regarding the scalability, recently neo4j can be used on Azure, so it must be quite easy to scale. To learn more how to scale neo4j, go to this page on neo4j.org.
UPDATE: in the newest version of Neo4j, there is added the support for a new query language - http://blog.neo4j.org/2011/06/kiruna-stol-14-milestone-4.html.
I have an existing library written in C# which wraps a much lower-level TCP/IP API and exposes messages coming down the wire from a server (proprietary binary protocol) as .NET events. I also provide method calls on an object which handles the complexities of marshalling convenient .NET types (like System.DateTime) down to the binary encodings and fixed-length structures that the API requires (for outgoing messages to the server). There are a fair number of existing applications (both internally and used by third parties) built on top of this .NET library.
Recently, we've been approached by someone who doesn't want to do all the legwork of abstracting the TCP/IP themselves, but their environment is strictly non-Windows (I assume *nix, but I'm not 100% sure), and they've intimated that their ideal would be something callable from Java.
What's the best way to support their requirements, without me having to:
Port the code to Java now (including an unmanaged DLL that we currently P/Invoke into for decompression)
Have to maintain two separate code-bases going forwards (i.e. making the same bug-fixes and feature enhancements twice)
One thing I've considered is to re-write most of the core TCP/IP functionality once into something more cross-platform (C / C++) and then change my .NET library to be a thin layer on top of this (P/Invoke?), and then write a similarly thin Java layer on top of it too (JNI?).
Pros:
I mostly spend my time writing things only once.
Cons:
Most of the code would now be unmanaged - not the end of the world, but not ideal from a productivity point of view (for me).
Longer development time (can't port C# sockets code to C / C++ as quickly as just porting to Java) [How true is this?]
At this point, the underlying API is mostly wrapped and the library is very stable, so there's probably not a lot of new development - it might not be that bad to just port the current code to Java and then have to make occasional bug-fixes or expose new fields twice in the future.
Potential instability for my existing client applications while the version they're running on changes drastically underneath them. (Off the top of my head I can think of 32/64 bit issues, endianness issues, and general bugs that may crop up during the port, etc.)
Another option I've briefly considered is somehow rigging Mono up to Java, so that I can leverage all of the existing C# code I already have. I'm not too clued up though on how smooth the developer experience will be for the Java developers who have to consume it though. I'm pretty sure that most of the code should run without trouble under Mono (bar the decompression P/Invoke which should probably just be ported to C# anyway).
I'd ideally not like to add another layer of TCP/IP, pipes, etc. between my code and the client Java app if I can help it (so WCF to Java-side WS-DeathStar is probably out). I've never done any serious development with Java, but I take some pride in the fact that the library is currently a piece of cake for a third-party developer to integrate into his application (as long as he's running .NET of course :)), and I'd like to be able to keep that same ease-of-use for any Java developers who want the same experience.
So if anyone has opinions on the 3 options I've proposed (port to Java & maintain twice, port to C and write thin language bindings for .NET and Java or, try and integrate Java and Mono), or any other suggestions I'd love to hear them.
Thanks
Edit: After speaking directly with the developer at the client (i.e. removal of broken telephone AKA Sales Department) the requirements have changed enough that this question no longer applies very well to my immediate situation. However, I'll leave the question open in the hopes that we can generate some more good suggestions.
In my particular case, the client actually runs Windows machines in addition to Solaris (who doesn't these days?) and is happy for us to write an application (Windows Service) on top of the library and provide a much more simplified and smaller TCP/IP API for them to code against. We will translate their simple messages into the format that the downstream system understands, and translate incoming responses back for them to consume, so that they can continue to interface with this downstream system via their Java application.
Getting back to the original scenario after thinking about this for a couple of weeks, I do have a few more comments:
A portable C-based library with different language bindings on top would probably be the way to go if you knew up front that you'd need to support multiple languages / platforms.
On *nix, can a single process host both a Java runtime and a Mono runtime simultaneously? I know in earlier versions of .NET you couldn't have two different .NET runtimes in the same process, but I believe they've fixed this with .NET 4? If this is possible, how would one communicate between the two? Ideally you'd want something as simple as a static method call and a delegate to raise responses with.
If there's no easy direct interface support between Java & Mono (methods & delegates, etc.), one might consider using something like ZeroMQ with Protocol Buffers or Apache Thrift as the message format. This would work in-process, inter-process and over the network because of ZeroMQ's support for different transports.
Spend more time getting the requirements nailed down before deciding on an implementation. Until you know what is required, you don't have any criteria for choosing between designs.
If it's a non-windows environment, it doesn't make sense to have .NET anywhere in there, for example.
If you need something that runs on the Java Virtual Machine but looks a lot like C#, you should check out Stab. This will not help you with P/Invoke and the like but you may find it less work to port your C# code to Java and maintain it.
You should look into Mono though. I expect that all your C# code would run unmodified (except the parts that touch the unmanaged DLL).
I have not used it but jni4net is supposed to allow calling .NET code from Java. If your clients want a Java interface, this may be a solution.
I use Mono on Linux and the Mac all the time even when .NET compatibility is not a priority. I like C# and the .NET libraries and prefer the CLR to the JVM. Mono is MIT/X11 licensed which means that you can use it commercially if you like. Unlike some others, I see no reason to avoid technology championed by Microsoft while favouring technology championed by Oracle and IBM.
Using Mono will not help you with the unmanaged bits, although you can still P/Invoke into a native DLL. You will just have to port that DLL yourself or find some equivalent.
You may also want to look into Mono Ahead of Time compilation.
Have you considered mono? It would most likely support your existing code in the non-windows environment. The trick would be calling it from java, but the mono folks might have something to help you out there, too.
This probably isn't the right solution in your case, but for completeness:
There are a few languages that can target both the JVM and .NET, in particular Ruby (JRuby and IronRuby) and Python (Jython and IronPython). Scala might eventually get there too, although right now the .NET version is a long way behind the JVM version.
Anyway, you could potentially rewrite your library in Ruby or Python and target both runtimes.
If what you really, really want is to be able to code in .NET and have it run on the JVM, you could check out Grasshopper (2015-09: link possibly dead). That is what it is designed to do.
I know the Mainsoft guys have been contributors to Mono over the years. If I remember correctly, they wrote the Visual Basic compiler for Mono.
There is also the C# to Java converter from Tangible. I have heard good things but I have never used it myself.
Also, it does not help your situation much but I should point out Mono for Android.
Mono for Android runs the CLR and the Dalvik VM in parallel. In other words, the C# code you wrote for Android can be calling into Java libraries (like the Android UI for example) and executing as a single app. You had asked about the ability to run .NET and Java code in the same process. Clearly, it can be done.
One thing I've considered is to re-write most of the core TCP/IP functionality once into something more cross-platform (C / C++) and then change my .NET library to be a thin layer on top of this (P/Invoke?), and then write a similarly thin Java layer on top of it too (JNI?).
That's a possibility. On the Java side, you should consider using JNA rather than JNI. (If you use JNI, the C / C++ code needs to be written to use JNI-specific signatures.)
Another possibility is to replace the proprietary binary protocol with something that "just works" with multiple programming languages. This is the kind of problem space where CORBA and similar technologies provide a good solution.
Any idea on interfacing with AutoCAD through a JAVA program. I am looking for a solution that can directly interface with an AutoCAD session (even start one), the way it works with the .NET extensions of AutoCAD. Or any way to work with ObjectARX through JAVA, definitely not writing a complete JNI wrapper over it.
Added: We are looking for something in open-source. In case there is none, we are ready to create one in open-source if someone can lend a helping hand explaining how it can be done. We have taken a look at JNA and JaWin. JNA clubbed with JNI might help but is too ugly. JaWin on the other hand has not been updated in the past 4 years, so sort of skeptical using it.
The only thing I can think of is to use a Java <-> .Net bridge like JNBridge. I've used this in other scenarios and it works fine. Never done any work with Java and AutoCad though so there might be other cheaper solutions.
If you are trying to interact with the AutoCAD application you will have a tough time.
If you want to interact with the dwg files themselves there is the Open Design Alliance which has libraries that allow working with dwg files without AutoCAD.
You can try to use the JavaBeans ActiveX bridge and the COM Automation to open AutoCAD and manipulate it.
That said, JavaBeans ActiveX bridge hasn't evolved in a while (I used it back in 2003) and Autodesk is seriously investing in .Net for everything related to extensions and automation in AutoCAD.
We are working on a similar project. What we are doing is writing the integration code in C#, and the business logic for our project in Java.
We are utilizing a C++ bridge that utilizes JNI to take Java calls down to C++, and then translates them back up to C#, and vice versa. Each function that needs to go from C# to Java has to be implemented in the bridge code. This is fairly involved, and there are some issues with getting the unmanaged C++ code to work with the C#, as well as the standard overhead of translating Jstrings into C# Strings and the like. The result is relatively fast, after we did some optimizations to insure that we aren't starting and stopping the JVM for each call into the Java layer.
We previously used COM objects which were called by the AutoCAD plugin, so that would be another approach.
I have a bunch of Java code which was written using the Hibernate framework, originally destined to have a front end written using JSPs. However, the requirements for the front end have changed, and we've decided that a desktop client (which will be written in .NET) is a better match for our users.
I don't really want to waste the code that's already been written - can anybody suggest a good set of tools for writing a document-based web services interface that we will be able to access from .NET?
Thanks,
Jim
If you truly want a document based service interface (rather than an RPC style web service architecture), your best bet is going to be creating a SOAP based web service interface.
A quick glance at the Java site shows that the Metro stack might help a bit:
Java Web Services at a Glance
We're developing an application with the exact architecture you describe for a finance application. We reviewed several different options, and have finally landed on using compressed CSV over HTTP.
CSV was chosen since the vast majority of data was going to be displayed in a grid on the front end, we had very large result sets >250k rows on a regular basis, and it compresses really really well.
We also looked at using:
ICE, but declined on that due to licensing costs and the need to reinvent so much.
Google's protocol buffers via servlets, but declined on that due to lack of C# support (as of last fall).
Compressed XML using WOX, but declined on that due to lock-in to a small thesis project for support and XML being too verbose.
The industry supports a couple of different options as well:
SOAP, but that has its own well documented issues.
IIOP, J-Integra has a product called Espresso which will allow you to do RMI from a front end.
I'd personally use some lightweight RPC protocol, be it XML-RPC or a homegrown one. SOAP, IMO, is way too fat and is not as interoperable as it's supposed to be. The simpler the better.
We have a quite large application using a Java RMI server and IIOP.NET for interoperability. We have used IIOP.NET with the Sun RMI and the Bea Weblogic (now Oracle) without major issues.