im trying to understand where WSDL's fit in, in a typical web service backend application. i am coming from a Spring background and in my experience so far, in Spring, each url request gets mapped to a specific controller class via a dispate servlet running in the web container. you can specify which url matches a given controller via xml config or from annotations.
is using a WSDL the same thing as using an xml config file to map url requests to java objects?
Thanks in advance. im moving from Spring to standard j2ee/EJB3.
WSDL is just a description of Web Service interface, most Web Service systems generate those descriptions on fly like for example when you create asmx web services you can generate WSDL on fly by typing http://yourhost/yourwebcontext/yourwebservicename.asmx?wsdl and it will return you the description of that web service. Then you can use a tools that generate stub proxies for coding using those descriptions automatically, for example in Visual Studio when you add an Web Service Reference those operations are done automatically
No, WSDLs are not like a dispatch servlet.
A WSDL file is a description of a web service (SOAP, REST, etc.). A WSDL can (theoretically) be used by anyone to generate executable code which consumes the web service described by that WSDL.
From the WSDL tag info:
"WSDL" stands for "Web Services Description Language." It is an XML language used to describe a web service to code that wishes to consume it. It describes the messages sent and received, the possible faults, and the communication and security requirements.
From WSDL Essentials:
In a nutshell, WSDL represents a contract between the service requestor and the service provider, in much the same way that a Java interface represents a contract between client code and the actual Java object. The crucial difference is that WSDL is platform- and language-independent and is used primarily (although not exclusively) to describe SOAP services.
Using WSDL, a client can locate a web service and invoke any of its publicly available functions. With WSDL-aware tools, you can also automate this process, enabling applications to easily integrate new services with little or no manual code. WSDL therefore represents a cornerstone of the web service architecture, because it provides a common language for describing services and a platform for automatically integrating those services.
Related
I have a system (kind of aggregator) that integrates with hundreds of different SOAP services - most of them do the same business functionality, but each service having different data structure in SOAP request & very few having 2 API calls to complete one transaction.
The present service integration workflow is
create stubs from WSDL
map data to the generated stub api
setup a new endpoint to fire this api
I see this a repeated, unintelligent work & requires development effort for every new service integration.
Was there different approaches to integrate with lot many systems? Any libraries that can generate soap requests based on configurations, or I have to rely on some Java SOAP, Spring lirbaries to create custom SOAP xml request from my own configurations? I see Spring's WebServiceGatewaySupport for webservice client but requires stubs created from wsdl?
Is it wise to define soap request xml as templates for every service, generate xml with input data?
Other ways I thought was to develop each integrations as independent microservice layered under an API gateway that routes each requests to specific service. But this design approach will have hundreds of services running, consuming more resources (in case of Spring boot).
Generate stubs & deposit the jar to disk, load this jar with a classloader & use the stubs using reflection - not so simple, I believe.
Use of serverless looks promising but is not possible immediately.
I have a spring mvc application which runs correctly,now another colleague wants to call the same functions from another application but he needs REST URL of my functions.
how is it possible to provide the same functionality through spring REST?
is it just with new annotations .please provide some resource to show me how to do it.
when server has a service, only legal clients which had any contracts with server can access it. And clients can use service by the way such as: use RestTemplate to get/post request to URL of service, and clients can get data as JSON, or XML type if you have an equivalent object as this image:
Also, a service can be support as a interface, ex: google search is a service supported by google, but it's not rest service.
If you know each other URL address you can consume each other REST API from java code by using RestTemplate object.
I would advise you to go over the Spring starter guide which deals with that issue, here is the link (Consuming a RESTful Web Service):
https://spring.io/guides/gs/consuming-rest/
We have a web application using Jersey and Spring's rest template. Does anyone know of a tool that can scan a code base and produce a report that lists all exposed endpoints and also internal references to those endpoints?
You may also take a look at Swagger, a framework for describing, producing, consuming, and visualizing RESTful web services.
Swagger supports multiple REST frameworks and also JAX-RS based on Jersey.
From their GitHub Wiki:
The Swagger framework simultaneously addresses server, client, and documentation/sandbox needs for REST APIs. As a specification, it is language-agnostic. It also provides a long runway into new technologies and protocols beyond HTTP.
With Swagger's declarative resource specification, clients can understand and consume services without knowledge of server implementation or access to the server code. The Swagger UI framework allows both developers and non-developers to interact with the API in a sandbox UI that gives clear insight into how the API responds to parameters and options. Swagger happily speaks both JSON and XML, with additional formats in the works.
Jersey can provide a WADL report at the /application.wadl URI. It doesn't document complex types but at least gives you a list of endpoints.
See https://wikis.oracle.com/display/Jersey/WADL
I want to write a ruby web service client for a SOAP (JAX-WS) web service. I looked into soap4r and handsoap but couldn't find useful resources to write a (JAX-WS) client
Can you help me to find some resources and some way of doing it. Because as I can see, my web service is developed using oracle JDeveloper and looks little different than examples find in web.
I'm a beginner for SOAP, WSDL web services and finding it hard.
Has anyone done something like this before, or can you turn me to the correct direction?
JAX-WS is an API for the development of web services in Java. Know then that, in order to consume a SOAP/WSDL based web service, it is not necessary to know how that web service was implemented. It could be Java, .NET or any other number of languages. All that is required to create a SOAP based web service client is the WSDL for the service. It is self contained and self descriptive, including all operations and data types supported by the web service.
In order to familiarize yourself with web services, I would recommend trying to exercise some web services directly, for example using SoapUI. This will allow you to import a WSDL for an active web service, try out some of the operations, and see what the corresponding SOAP messages look like. Then, I would look at "What's the best way to use soap with ruby?" for more ruby specific approaches.
My standard WCF/ RESTful service is going to return big complex object.
In WCF as and when someone adds the service reference it creates a proxy of it, i.e. I am exposing data contract to client and its strongly typed at the client level.
How are we going to do with RESTful service, is there anyway to the same for RESTful service.
One of the benefits of RESTful services is that they are lightweight. That implies no infrastructure like WSDL files, proxies, etc.
RESTful services are not self-describing, so you don't have to worry about providing a WSDL file; maintaining all the schemas online, etc.
If the payload is complex, then why are you using REST? Just because it's a fad? Do the operations on your service correspond to HTTP operations on "resources" as the HTTP Protocol specification defines it?
If not, then don't use REST.