ESB webservice adaptor - java

Does the webservice adaptor's function is let different webservice(eg,http/jms) can call each other?Does it like a proxy such as transform soap/http webservice to soap/jms webservice?
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In the picture there exist three webservice,webservice-1 and webservice-1 are published by third part,adaptor-A and adaptor-B are used to call them,webservice-3 is published by adaptor-c.first,when someone call webservice-3,the adaptor-c intercept the soap request and send it to esb ,the esb have a broadcast router and the router send it to adaptor-A & adaptor-B,adaptor-A & adaptor-B then analyse the message and call webservice-1&webservice-2.after that adaptor-A & adaptor-B send webservice response to esb,esb also have a aggregator in it,then aggregator assemble these two response and send it to adaptor-c,At last,adaptor-c send the final result to webservice-3 user!
I want to if this flow is feasible?if feasible,how to design the adaptor-A and adaptor-B and adaptor-c?

yes, this is well suited scenario for an ESB. When your adapters don't implement a special business logic and are only responsible for "speaking" the protocol expected by the Web service, you can probably connect the services directly to the ESB. This kind of "protocol virtualization" is basically provided by all kinds of ESBs, even plain Web service stacks like Axis2 or CXF can deal with a large set of transport protocols.
Regarding the business logic there are different possibilities. For simple scenarios you can consider using a EIP-aware framework like Apache Camel and chain Enterprise Integration Patters (EIP) [Hohpe et al] to achieve the desired integration. For more complex scenarios you can consider using BPEL (Business Process Execution Language). BPEL is descriptive parallel programming language with focus on orchestrating Web services in a transactional, long-running fashion. BPEL can be executed e.g. by Apache ODE.

Related

exposing soap as rest service in java

I have a vendor web service which is in SOAP but I have to write a wrapper class and expose it as Rest. Is it possible??
it will be something like client will call Rest Service but internally rest service will call Soap service.
It's certainly possible, and quite common actually. Writing middleware/glue/wrapper code is done all the time.
The approach I would take is to generate the client code using your vendors web service WSDL - for example using Axis wsdl2java. This generated code can be put into it's own lib/jar. Then write your own REST code using whatever framework you want that leverages the lib you created.
Clients would call your REST service which would internally use the lib code to connect to your vendors web service.
1)
Protocol Bridging SOA Patternis used to transform between different protocols by using a bridging broker as intermediary. The broker holds the transformation logic. bridges are available in most ESBs and EAI middle-wares.
http://soapatterns.org/design_patterns/protocol_bridging
2) Write your own logic adopter read Soap request convert in your code and expose as rest .

Business logic in java websocket endpoint/JAX-RS?

What's the best practices for implementing business logic in a web-application that uses a Websocket connection? specifically, how to use a Java websocket endpoint effectively to implement services and functionalities of the system?
Does the websocket endpoint replace Java web-services (JAX-RS) functionality entirely?
WebSocket is not a replacement for JAX-RS.
Both technologies have their usecases; if I were you, I would do my research before asking questions like this one.
The first question is about the business logic - and that always depends. You can adapt in some way MVC patter when dealing with JAX-RS, since there is a tight connection between Http Request and Response and you can even use some templating engine to process your output (Jersey - JAX-RS RI - contains pre-built support for this scenario). WebSocket is very different in terms of data processing, there is one "persistent" TCP connection which you can use to transmit messages from/to either side, which usually requires different programming model and typical usecase would include sending/receiving short status update messages to some interactive front-end (javascript) application.

Advice on implementing JAX-WS web services to be consumed by non-Java (PHP) endpoint

I am a Java SE programmer and exploring implementing JAX-WS web services for the purpose of integrating with our web server. To this date, I have not had experience with web-services thus would like to get everyone’s expert opinion.
The background is that my company has a POS system developed and hosted in-house using Java SE. We are planning for e-commerce capabilities, which will be implemented in HTML/PHP, via external web development company and hosted externally.
Thus we are exploring implementing JAX-WS web services on our endpoint for the purpose of integrating with our e-commerce server running PHP endpoint.
I’ve done some research and my understanding is that:
it is possible to implement JAX-WS without Java EE containers
JAX-WS Web Services Without Java EE Containers
it is possible to mix end-point technologies, and specifically in my case JAX-WS as our endpoint and PHP SoapClient on our e-commerece end-point
PHP SOAP Client to consume JAX-WS with Basic Http Authentication
Using PHP SoapClient with Java JAX-WS RI (Webservice)
I am now wondering what’s is the proper approach when discussing implementation with the external web development company that is building our e-commerce platform. Most web sites and forums’ examples assumes Java on both endpoints and that both endpoints are implemented by the same developer/team.
Based on my limited understudying, I gather the process would be:
Me/my company creating the web service (coding the web services methods in Java)
Me/my company creating the server program
The wsdl generated from the URI (http://:/md5WebService?wsdl )of my server program is then used as the interface contract between our internal POS system and the external e-commerce platform
The web development company that is implementing the e-commerce platform then uses the wsdl to implement the PHP SoapClient endpoint on their side.
And in the case where our internal POS system need to consume a web services created by the external web development company, they will pass me the wsdl and I use that to make the call to them.
Is this the correct way to do proceed?
Many thanks.
Cheers,
Arthur
In Java you have actually two ways to start your design of your web service. You can either create the WSDL (Web Service Description Language) contract first (contract first approach) and then let Java or some framework tools create Java skeleton classes for you which you can use to implement the logic of each operation or you can start by code first approach and implement each web method and its logic and then let Java or some external framework tools generate the WSDL contract for you.
Either way you start, the result should be very similar and platform independent. The standard message format used for WSDL based web services is SOAP (Simple Object Access Protocol) which is based on XML (eXtensible Markup Language) which is by definition platform and programming language neutral.
So, after implementing your service and starting a server for the WS endpoint adding ?wsdl to the end of the endpoint URL should return the WSDL contract to the invoker, which can be used to create client side stubs for the required programming language which furthermore simplify the sending and receiving of messages from and to the web service. Note however that creating stub files might not be needed as all the information may be parsed from the WSDL contract directly. As of lack of knowledge concerning PHP I can't give details on how to call a WS from PHP directly or if stub file creation is required/recommended.
In order to call an other WS from your service you need to create a WS client within one of your web methods and invoke one or more of the operations offered by the remote WS and process the response within your web method.
As I am not sure if you are using any (Java) frameworks like f.e. Apache CXF I am not giving any code examples here. For integrating external web services within your service you might also have a look at Apache Camel which offers integration support for numerous Java based frameworks including CXF. Here your web service is treated as a Consumer while other external services you need to invoke are handled as Producers. The interaction between your internal and the external services is modeled here within a route where you can apply various Enterprise Integration Patterns (EIP) like splitting multiple elements contained within a response into distinct objects which you furthermore can process in parallel.
In general your enumeration of steps involved does look right if you follow the code first approach but as mentioned earlier you can also start by defining your contract first. Depending on your knowledge of the WSDL/XSD syntax (the less you know the exact syntax the more you should use code first approach), crating the contract first might enable PHP side integration sooner while you still develop the internal logic of your implementation.
it is possible to mix end-point technologies, and specifically in my case JAX-WS as our endpoint and PHP SoapClient on our e-commerece end-point PHP SOAP Client to consume JAX-WS with Basic Http Authentication Using PHP SoapClient with Java JAX-WS RI (Webservice)
This is the exact purpose of introducing webservice concept. You don't have to worry about on which platform or language your client and server is implemented. Client and server will simply exchange xml messages (platform independent) as agreed upon within wsdl.
Go ahead with your understanding.

Web Services vs Messaging

What kind of arguments one should use when choosing between integration using web service vs JMS? I'm familiar with basics of both approaches however in some cases it is unclear as to which one would be the best for a given situation. I guess I'm looking for a high overview comparison with use cases.
thanks
JMS is a messaging service. It is asynchronous and 2 directional, i.e. you can write application that both sends and receives messages. But this must be application implemented typically in java. I mean it cannot be thin client. And standard protocol of JMS is TCP based, so it may be blocked by firewall.
Web service is designed as a transport over HTTP, so it typically passes firewalls. But it is one directional: client calls server; server cannot call client. It just can response client's calls. Client of web service (especially RestFull web service) is very simple, so it can be easily implemented as a thin client (e.g. AJAX client).
Good question.
I will use Web Service when:
1. Dealing with cross domains, typically services environment when I am not sure about the client technology.
2. Need Synchronous response.
And pickup Messaging when (Hope you mean Messaging not just Java version):
1. Need Asynchronous request/response.
2. High Availability.
3. Confirmed Delivery.

Main differences between SOAP and RESTful web services in Java [duplicate]

This question already has answers here:
SOAP vs REST (differences)
(13 answers)
Closed 5 years ago.
For now I have a slight idea about the differences between SOAP and RESTful services.
My question is when I should use SOAP, and when I should use RESTful; which one is "better" when it comes to performance/speed or request handling?
I'm implementing it for the first time in RESTful (Java) and I want know more about it; I've dealt with SOAP before.
This is a follow-up question to this post.
REST is almost always going to be faster. The main advantage of SOAP is that it provides a mechanism for services to describe themselves to clients, and to advertise their existence.
REST is much more lightweight and can be implemented using almost any tool, leading to lower bandwidth and shorter learning curve. However, the clients have to know what to send and what to expect.
In general, When you're publishing an API to the outside world that is either complex or likely to change, SOAP will be more useful. Other than that, REST is usually the better option.
REST vs. SOAP Web Services
I am seeing a lot of new web services are implemented using a REST
style architecture these days rather than a SOAP one. Lets step back a
second and explain what REST is.
What is a REST web service?
The acronym REST stands for representational state transfer, and this
basically means that each unique URL is a representation of some
object. You can get the contents of that object using an HTTP GET, to
delete it, you then might use a POST, PUT, or DELETE to modify the
object (in practice most of the services use a POST for this).
Who's using REST?
All of Yahoo's web services use REST, including Flickr and Delicious.
APIs use it, pubsub, bloglines, Technorati, and both eBay, and Amazon
have web services for both REST and SOAP.
Who's using SOAP?
Google seams to be consistent in implementing their web services to
use SOAP, with the exception of Blogger, which uses XML-RPC. You will
find SOAP web services in lots of enterprise software as well.
REST vs. SOAP
As you may have noticed the companies I mentioned that are using REST
APIs haven't been around for very long, and their APIs came out this
year mostly. So REST is definitely the trendy way to create a web
service, if creating web services could ever be trendy (lets face it
you use soap to wash, and you rest when your tired). The main
advantages of REST web services are:
Lightweight - not a lot of extra XML markup Human Readable Results
Easy to build - no toolkits required. SOAP also has some advantages:
Easy to consume - sometimes Rigid - type checking, adheres to a
contract Development tools For consuming web services, its sometimes a
toss up between which is easier. For instance Google's AdWords web
service is really hard to consume (in ColdFusion anyway), it uses SOAP
headers, and a number of other things that make it kind of difficult.
On the converse, Amazon's REST web service can sometimes be tricky to
parse because it can be highly nested, and the result schema can vary
quite a bit based on what you search for.
Whichever architecture you choose make sure its easy for developers
to access it, and well documented.
Freitag, P. (2005). "REST vs SOAP Web Services". Retrieved from http://www.petefreitag.com/item/431.cfm on June 13, 2010
SOAP
Simple Object Access Protocol (SOAP) is a standard, an XML language, defining a message architecture and message formats. It is used by Web services. It contains a description of the operations.
WSDL is an XML-based language for describing Web services and how to access them. It will run on SMTP, HTTP, FTP, etc. It requires middleware support and well-defined mechanism to define services like WSDL+XSD and WS-Policy.
SOAP will return XML based data
REST
Representational State Transfer (RESTful) web services. They are second-generation Web services.
RESTful web services communicate via HTTP rather than SOAP-based services and do not require XML messages or WSDL service-API definitions. For REST middleware is not required, only HTTP support is needed. It is a WADL standard, REST can return XML, plain text, JSON, HTML, etc.
REST is an architecture.
REST will give human-readable results.
REST is stateless.
REST services are easily cacheable.
SOAP is a protocol. It can run on top of JMS, FTP, and HTTP.
REST has no WSDL (Web Description Language) interface definition.
REST is over HTTP, but SOAP can be over any transport protocols such as HTTP, FTP, SMTP, JMS, etc.
REST stands for representational state transfer whereas SOAP stands for Simple Object Access Protocol.
SOAP defines its own security where as REST inherits security from the underlying transport.
SOAP does not support error handling, but REST has built-in error handling.
REST is lightweight and does not require XML parsing. REST can be consumed by any client, even a web browser with Ajax and JavaScript. REST consumes less bandwidth, it does not require a SOAP header for every message.
REST is useful over any protocol which provide a URI. Ignore point 5 for REST as mentioned below in the picture.
REST vs. SOAP
SOAP:
► SOAP is simple object access protocol that run on TCP/UDP/SMTP.
► SOAP read and write request response messages in XML format.
► SOAP uses interface in order to define the services.
► SOAP is more secure as it has its own security and well defined standards.
► SOAP follows RPC and Document style to define web services.
► SOAP uses SOAP-UI as client tools for testing.
REST
► REST is representational state transfer that uses underlying HTTP protocols.
► REST is stateless.
► REST is an architectural style that is used to describe and define web services.
► REST can read and write request response messages in JSON/XML/Plain HTML.
► REST uses URI for each resource that is used in web service.A resource can be image text method etc.
► REST uses set of verbs, like HTTP's GET, POST, PUT, DELETE.
► REST is easy to develop and easy to manage as compared to SOAP UI.
► REST has light-weight client tools or plugins that can easily be integrated inside a browser.
► REST services are cacheable.
Difference between REST and SOAP:
SOAP Web services:
If your application needs a guaranteed level of reliability and security then SOAP offers additional standards to ensure this type of operation.
If both sides (service provider and service consumer) have to agree on the exchange format then SOAP gives the rigid specifications for this type of interaction.
RestWeb services:
Totally stateless operations: for stateless CRUD (Create, Read, Update, and Delete) operations.
Caching situations: If the information needs to be cached.
SOAP web service always make a POST operation whereas using REST you can choose specific HTTP methods like GET, POST, PUT, and DELETE.
Example: to get an item using SOAP you should create a request XML, but in the case of REST you can just specify the item id in the URL itself.
REST is easier to use for the most part and is more flexible. Unlike SOAP, REST doesn’t have to use XML to provide the response. We can find REST-based Web services that output the data in the Command Separated Value (CSV), JavaScript Object Notation (JSON) and Really Simple Syndication (RSS) formats.
We can obtain the output we need in a form that’s easy to parse within the language we need for our application.REST is more efficient (use smaller message formats), fast and closer to other Web technologies in design philosophy.

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