I am having a Java application and a .NET application both residing in two different machines and need to design a communication layer between these two applications. Any inputs or ideas would be really helpful. Below mentioned is the nature of interaction between these two applications.
Java applications sends large amounts of data to the .NET application
Data latency should be kept to a minimum
.NET application should also be able to request for some data (synchronously/asynchronously)
The easyest way .Net and Java can talk is using Web-Services - we have done in my company with much success (using apache's cxf and standard code on the .Net side).
But if latency and size are the main requirements, you should use Sockets - both platforms offer a pretty extensive socketing frameworks and it would give you the best performance possible.
I think this can be done by setting up an xml webservices layer on the java side. You can use RestEasy for restful web services. Just my .2 cents.
Another alternative is some form of MOM (Message Oriented Middleware). There are a lot of implementations, but one to look at first might be ActiveMQ as it has both Java and C# bindings (among others).
I'm not saying this is better than using a web-service, it entirely depends on what your requirements are.
We have had good experiences with providing web services with JAX-WS (part of standard runtime in Java 6). They explicitly list .NET compatibility as a goal and is well supported in IDE's.
The Endpoint.publish() mechanism allow for small, simple deployments.
You can use Web Services. Jax-WS is the API in java that allow you to use it. As the implementation of this API I recommend metro (http://metro.java.net/), this already came with the SDK, and has a great integration with netbeans.
As already someone referred yet, you can use a socket, and create a communication channel on that, but this have some problems, starting with security. Don´t use this in real life applications.
If you need help with this subject you can start reading this:
Getting started with JAX-WS
It really depends on your requirements. The simple way is generally Web services. However, if you want higher performance, or more fine-grained access to the API on the other platform, you might want to consider JNBridgePro (www.jnbridge.com).
Disclosure: I work for JNBridge.
Related
I have an enterprise Java web application deployed in tomcat.
I am looking for ways to integrate a HTML & JS UI with the mid tier java code. So far, from looking around I have read that there are two ways to do this which fit my requirements :
1) DWR - Direct web remoting
2) Use REST web services.
I am not sure which approach to use.
Edit: What is the advantage of using DWR over a rest WS design?
Is there a better approach available? Some people asked me to have a look at GWT, but I am not sure if these are scalable.
Edit 2: I will most likely be using dojo for the UI development(Works well with REST/DWR??), and I want to keep the java code chages minimal. I understand that by using web services, I would have to write an additional WS client layer on top of the existing java code.
Also, the usual enterprise needs, performance, scalability, etc.
Ok so you're building a web client frontend to your java backend, there are a few ways to go about this:
You want to use java standards as much as possible, preferably living in the java EE world: JSF. You will need some knowledge of HTML, XML and perhaps even javascript (though limited). Personally I have had a pretty buggy experience with JSF+richfaces to the extent that I don't use it anymore.
You are very well acquainted with java desktop application development but don't know much about javascript: vaadin: it allows you to write plain java using desktop application terminology which will be compiled to javascript. Currently I am working on a big vaadin project and it is very nice to be working with pure java in eclipse, the downside is however that you are far removed from the actual frontend, so tweaking can be tricky. Additionally everything is stored in sessions (afaik) and scales poorly.
You are primarily a frontend person with unrivaled javascript skills: use a REST interface in java and a pure js/html/css frontend. Personally I think this is the cleanest design and I have designed a few of my own applications like this. The downside is that managing large javascript projects tends to be hard because...well...javascript sucks. The upside is that this will always be the fastest most lightweight option available to you.
Ideologically I would definitely suggest the last approach but this can be hard for large projects. If you have the hardware to throw at it, vaadin is a nice option. My JSF 2 experience was a bit disappointing due to the bugs in (necessary) third party libraries like richfaces.
PS: I have never heard of DWR but the last stable release seems 2 years old and all it seems to do is expose java code as javascript methods which can be better handled with a REST interface.
Open interface standards like REST and SOAP make it easy to build code to consume these services if you are using frameworks to build a REST Client and a SOAP client code respectively. But the point is that you need to have this client code to make calls to these services.
DWR on the other hand, generates this client code. Your java classes are ready to be called (like you would do in Java).
Assume we have a .NET application that exposes its web services. This app needs to be integrated with our J2EE application running on Weblogic. Both are internal applications so we don't worry too much about security.
There are no really complex data structures/types so we should be able to map them between .NET and Java tier (or at least write adapters on the Java tier to ensure the match).
What is the best approach of consuming these .NET web services in the J2EE application?
The simple approach would be to just generate WSDLs for the .NET web services, and generate Java client classes using wsdl2java or other similar tool and see if that can work without adapters/changes, create unit tests, etc. But in case of data related challenges we may need to deal with XSD/Schemas, generating classes, etc.
I know there is WSIT to deal with interoperability issues, but want to keep this as simple as possible. Any thoughts, ideas?
You could connect the two applications with a RESTful API. This lets them talk in a shared, high level API over HTTP. Both languages have plenty of support for both creating and using HTTP/RESTful services, so this should be fairly simple to implement in either language.
I'm developing a web application with multiple frameworks (spring, hibernate, spring-security, ZK for GUI), and using Tomcat as app server. I must say I have absolutely no experience with java web services technologies. Thing is, I will almost certainly have to expose number of services for some external applications in the near future, and I was wondering what would be the way to go (considering the frameworks I'm using)...
I saw and read various tutorials and some questions (link) regarding Axis, Axis2, JAX-WS... Thing that confuses me a little bit is that I don't know what is the common practice (if any) to integrate services within existing web application (mainly in the terms of project organization). As I see it now, these services that I need to implement will rely partially on the existing source code, so I don't know whether I should use completely separate project, or I can put it inside my existing web app folder (which I tried with Axis2, but don't know if it's a good practice).
Thanks.
How to organize the projects?
In general I agree with #ericacm, but there is one thing you should keep in mind... You said you're going to develop a number of services in the near future. You may come to a point at which you want to host the services on a separate server, e.g. for performance, availability or maintainability reasons. This may influence your decision of separating the projects. Furthermore, separation "enforces" loose coupling, but therefore introduces other challenges like session sharing across multiple WARs. It's a case-by-case decision.
If I were in your situation I'd first ask myself whether the service(s) logically belongs to the web application or not.
Implementation
When in comes to WS-* implementations you have to make 2 decisions:
Decide for an API to use; today, I can't see any reason for not going with JAX-WS together with JAXB as API, they work well and they are standardized.
Decide for a Framework; I've experience using Axis2 as well as METRO (keep in mind that JSE 1.6+ provides basic JAX-WS support). Both work well. It's fairly easy to change the frameworks if you use the JAX-WS APIs.
I have good experience with Spring-WS 2+ and manual Castor mapping . Is is easy but powerful combination.
Spring-ws 2:
provides contract-first development (specially good for the web app with number of services).
provides WS annotation
supports XML mapping (Castor, JaxB, etc)
Castor:
mapping based on xml configuration
allows map multiple messages (requests/responses) to one java object (based on xml configuration)
If you are using some Java EE 6 server, consider also JAXB for manual mapping:
mapping based on annotation
should be faster than Castor
allows map multiple messages (requests/response) to one java object (when you use java inheritance)
You can go ahead and put them into the same project. Each web service will be an additional interface and implementation class along with some configuration.
Since you are using Spring CXF is a good choice as a for JAX-WS as it integrates well with Spring. See this page as a starter.
Spring-WS is complex framework for simple web services. If you want to understand web services completely and to know the nuts and bolts of web services, learn Spring-WS. It is extremely flexible and provides lot of options.
Else, if you want simpler alternative use JAX-WS. Spring supports JAX-WS annotations. Refer to the section 17.5.7. Exporting web services using the JAX-WS RI's Spring support.
http://static.springsource.org/spring/docs/2.5.x/reference/remoting.html
Is it possible to create WS Server and WS Client manually (without generators) by JAX-WS? Specially if you are developing a big application you want to re-use objects but generators are generating a lot of classes that can be in 99% the same (for example if your app is WS Client and you have to connect to badly designed external WS Server). Is there some tutorial how co create ws manually?
There is a lot of reasons why I don't like generators and completely agree with http://ogrigas.eu/spring/2010/04/spring-ws-and-jaxb-without-a-code-generator
I've always used the web service generation in Eclipse WTP to build my web service clients due to it's relative easy of use.
However, in the last couple years, as I've learned more about it I've seen the error of my ways.
I've read that one should use one of the plethora of other java web service client platforms such as CXF, Metro, etc.
At this point, I don't particularly care which platform I use - so long as it is not Axis.
My question is - the WTP tooling makes it easy to generate web service clients in java. Are there any similar tools, scripts, programs or tutorials that are of similar ease of use?
I don't really have time to learn all the intricacies of SOAP, RPC, etc. so please keep in mind that I'm not really trying to be lazy so much as I am pragmatic.
Thanks in advance.
SoapUI can generate the soap clients for many multiple java soap stacks like axis 1 & 2, xfire, GStep, JAX-WS, JAX-RPC, JBoss WS, Oracle Proxy, cxf, .Net, GStep. Here is the tutorial on how to do it.
So we want to develop a service app (web Service with post/get API). What is language to go for secure, fast, enterprise app for about 2000 employers to use with about 20~40 services for interacting with DB server (which in my case will be Oracle) Dev time a year Dev team of 3. All capable of righting C++ code as well as Java (so they will now them equally bad at the beginning of process)
Definitely java! You might want to check the jee6 tutorial on JAX-WS to get an idea of how web services are created using enterprise java (http://download.oracle.com/javaee/6/tutorial/doc/bnayn.html)
This will also guide you on how to do it using the netbeans IDE (http://netbeans.org/kb/docs/websvc/jax-ws.html)
Cheers!
You'd be masochistic to try this with C++! Definitely Java, J2EE whatever (look at various technologies from groups such as JBoss). The development process will be significantly faster using these existing technologies than writing your own...
The question is not what language to choose but which "architecture" or paradigm.
If you want/need to use SOAP then C++ might be fine, go and google for "gsoap". However I would recomend Java and REST as architecture paradigm, well we would need to know more what you really want to do. Perhaps some RMI or CORBA would be much easier. If you want to play with Java, Groovy or Scala (all languages run on the Java JVM), then google for "restlet".
Best Regards
Angelo
I would suggest using the Java / Netbeans combination.
Netbeans has a number of tools which makes web service development easy.
Good overview here.
Netbeans allows full use of JAX WS and Metro and is integrated with Glassfish and Tomcat servers (part of Netbeans download) so you can get up to speed really quickly.
you can use either C++ or Java depending what you're implementing. To see an example on C++ check out this great post by IBM Engineers: http://www.ibm.com/developerworks/webservices/library/ws-xml-rpc/