I have been seeing SOAP is "Heavy Weight" and REST is "Light Weight". On what parameters, we are telling REST is lightweight than SOAP?
We were using IFW model web services in our company earlier. But our management told us to develop all the new APIs going forward in REST. We are backend service providers in my company.
How REST is best useful for us?
What does "lightweight" means in context?
This question seems like repetition but don't understand the terms used.
REST gives you a session less window into a system. It does not track you, it does not care about you. All you have done is send a request which contains..hopefully some id to verify that you can make it. It may return a HTTP status code, it may return some body but ultimately, once the request is complete you are forgotten.
SOAP is heavy in a sense that it describes a "contract" between the remote system and your client. In order for your client to communicate effectively it MUST implement its schema...this is the SOAP skeleton. It describes the calls you can make and the objects you can expect back.
The reason why SOAP is heavy is because of serialization. Upon each SOAP request you typically serialize a java object, send it over HTTP and get a serialized response which is deserialized into an object via reflection...this is heavy. It also means that if the endpoint changes how they work, you must change your contract. You don't have to do this with REST.
With SOAP you run into multi threaded issues.
To answer quickly..
they might mean that a REST service is "lightweight" because you do not need to release changes to clients. You simply make changes to your logic, retaining URLS and the response should remain the same.
With SOAP...if you added a new field to an object, you would have to get the client to implement the new schema. SOAP is pretty old had.
REST is lightweight in that it and relies upon the HTTP standard to do its work. It is great to get a useful web service up and running quickly. If you don't need a strict API definition, this is the way to go. Most web services fall into this category. You can version your API so that updates to the API do not break it for people using old versions(as long as they specify a version). REST essentially requires HTTP and is format-agnostic, so you can use XML, JSON, HTML etc).
But the SOAP will wrap the structure into a SOAP envelope (follows an XML standard). The complexity of the SOAP envelope is based on the used message version and additional Web Service protocols. SOAP is generally transport-agnostic, meaning you don't necessarily need to use HTTP.
It can be pointed out that SOAP was designed for a distributed computing environment whereas REST was designed for a point-to-point environment.
I wonder if it is OK to say that while SOAP gives more security, REST-based API s will be easier on the resources and more scalable? As an example, Twitter, Facebook, Google Drive, Blogger, etc all have REST-based APIs that clients can consume.
Generally REST reduces the size and scope of request payloads by mapping request semantics to the underlying HTTP protocol. For example, SOAP will usually add an envelope (of varying complexity) which utilizes a WSDL (a contract) for both request and response types and service mappings. REST will just use POST, GET, etc to a URL with some HTTP encoded parameters and thus lacks an enforced contract.
There are several aspects of lightweight. SOAP is XML only, while REST allows you to send any payload, such as JSON which is less verbose and simpler than XML. Generally speaking, it takes less memory and less bandwidth to deal with JSON than XML.
On another level, using SOAP you typically describe everything as services. So, you need to define a message schema/structure for each verb and noun i.e. "CreateOrder". In REST, you use the predefined HTTP methods such as POST and put the noun/"resource" in the URI which uses already existing constructs on the HTTP level - not reinventing them in XML.
Then there is the effort it takes to adapt to change. A small change in SOAP requires you to redefine the schema, redefine the wsdl and handle versions. In rest, in the best of worlds, there is a degree of dynamic coded into the API (links to referenced resources, among other things), so that some changes can be implemented and takes effect directly.
All the heavy weight strictness of SOAP of course has a valid reason for existence. It's less likely two implementations have different interpretations of the API, than in a loosely defined REST API. SOAP also allows you to implement skeleton code in various languages based on a WSDL. In some complex scenarios, this is actually almost the only productive way to work with SOAP. Marshalling and unmarshalling between objects and serialized XML is rather heavy and adds to the heavyness of SOAP.
Related
I read a lot about why REST is preferred over SOAP and a lot of practical situations for that. But I could not find an article/answer on When SOAP can be preferred over REST. Can anyone please explain me a real time practical situation where SOAP can be preferred over REST?
NB - Please don't mark this question as duplicate without reading the question fully. This is not a duplicate of REST vs SOAP.
NB - Please don't mark this question as duplicate without reading the question fully. This is not a duplicate of REST vs SOAP.
when should you use SOAP? Representational State Transfer (REST) implements the standard HTTP/HTTPS as an interface allowing clients to obtain access to resources based on requested URIs. It is important to note that REST based services are stateless because http/https is natively stateless.
One of the many benefits for implementing HTTP/HTTPS as an interface is can be found in caching. Caching can be done on a web service much like caching is done on requested web pages. Caching allows for reduced web server processing and increased response times because content is already processed and stored for immediate access. Typical actions performed by REST based services include generic CRUD (Create, Read, Update, and Delete) operations and operations that do not require state.
Simple Object Access Protocol (SOAP) on the other hand uses a generic interface in order to transport messages. Unlike REST, SOAP can use HTTP/HTTPS, SMTP, JMS, or any other standard transport protocols. Furthermore, SOAP utilizes XML in the following ways:
Define a message
Defines how a message is to be processed
Defines the encoding of a message
Lays out procedure calls and responses
As REST aligns more with a Resource View, SOAP aligns more with a Method View in that business logic is exposed as methods typically through SOAP web service because they can retain state. In addition, SOAP requests are not cached therefore every request will be processed by the server.
As stated before Soap does retain state and this gives it a special advantage over REST for services that need to preform transactions where multiple calls to a service are need in order to complete a task. Additionally, SOAP is more ideal for enterprise level services that implement standard exchange formats in the form of contracts due to the fact that REST does not currently support this.
A real world example of where SOAP is preferred over REST can be seen in the banking industry where money is transferred from one account to another. SOAP would allow a bank to perform a transaction on an account and if the transaction failed, SOAP would automatically retry the transaction ensuring that the request was completed. Unfortunately, with REST, failed service calls must be handled manually by the requesting application.
References:
Francia, S. (2010). SOAP vs. REST. Retrieved 11 20, 2011, from spf13: http://spf13.com/post/soap-vs-rest
Rozlog, M. (2010). REST and SOAP: When Should I Use Each (or Both)? Retrieved 11 20, 2011, from Infoq.com: http://www.infoq.com/articles/rest-soap-when-to-use-each
When migrating from SOAP based webservices to RESTful, how complicated is the task? I have worked on them individually, but never on any migration. Can any one tell me the points that need to be taken into consideration when doing this? Not sure if its an appropriate question. More like a discussion thing.
The general approach on any situation like that can be to have a middle adapter/layer work between your existing system and newly developed system.
Converting an existing SOAP web service into RESTful web service can be tedious depending upon the complexity of existing system. Rather we can take alternative approach where an REST Adapter can be written that acts as a mediator between existing SOAP system and freshly developed REST web service.
This way can be done with minimum efforts and delivery can be fast. But again it depends on what is the system all about, how complex is current SOAP web service.
So with this approach end client will generate a REST request that will be landed on REST adapter and from Adapter to existing SOAP web service, takes back the response from your SOAP web service converts it back ready for REST client response. Intermediate JSON to XML and XML to JSON conversions can be easily handled.
This approach can be better as if required adapter can be turned off. This
I'm starting to choose a way to create my webservice, so i found 2 ways to do it:
1) Using the package javax.jws, with annotation #WebService:
#WebService(...)
public class MyServiceImpl {
2) The other way is using javax.ws, with annotation #Path:
#Path("/MyService")
public class MyServiceImpl
In my understand using the second solution is more simple, because when i need to create the Client i just need make a HTTP call (GET/POST). Using the first solution i need create a WSDL client, more complex solution.
So, I would like to know which is the advantage in use FIRST SOLUTION.
The SOAP/WSDL style is useful when a formal contract must be established to describe the interface that the web service offers.The Web Services Description Language (WSDL) describes the details such as messages, operations, bindings, and location of the web service.
Also the SOAP/WSDL style is useful when the application architecture needs to handle asynchronous processing and invocation (e.g. using JAX-WS the assynchronous clients can be created).
The disadvantages of SOAP/WSDL style are
its complexity: tools are required to create a client
heavier on Bandwidth : SOAP requires a heavy XML wrapper arround each request or response
complicated security rules
The advantages of REST style are
simplicity: REST client can be accessed from any browser (however, this is only true for GET method. Data creation request requires also the XML wrapper).
lighter on Bandwidth : data on the wire are usually bare xml elements (not wrapped within the <Envelope><Body> tags).
REST application security rules can be setup using the http standards: the administrator (or firewall) can discern the intent of each message by analyzing the HTTP command used in the request.
For example, a GET request can always be considered safe because it can't, by definition, modify any data.
The disadvantage of REST style is that it still doesn't cover all business requirements
There is no common standard accepted yet for the formal REST service description
REST requests (especially GET method) are not suitable for large amount of data
REST doesn't cover all web services standards, like Transactions, Security, Addressing, Trust, Coordination,
I saw these two links:
1.SOAP vs REST
SOAP vs REST 2
I understood the difference between the two. But I also heard about WADL (https://wadl.java.net/), which are used along with REST to provide a contract ( similar to SOAP WSDL does)
Now I have two questions:
REST is also adheres to the data type that is going to receive or transmit by WADL, which now acts very similar to SOAP ( with WSDL ).
If REST with WADL and SOAP are similar, which one to use?
Thanks in advance.
SOAP (Simple Object Access Protocol)
REST (Representation State Transfer)
SOAP and REST can’t be compared directly, since the first is a protocol and the second is an architectural style.
The main difference between SOAP and REST is the degree of coupling between client and server implementations. SOAP works like a custom desktop application, tightly coupled to server. There is rigid contract between client and server and everything seem like breaking is any of the side is changed. But, REST client is more like a browser. It’s a generic client that knows how to use a protocol and standardized methods. If done right, there would be less coupling.
A client is supposed to enter into REST without prior knowledge of the API, except for the entry point and the media type. In SOAP, the clients need to have the prior knowledge of everything it will be using.
REST is protocol independent. It’s not coupled to HTTP. We can use it for any protocol for which there is standardized URI scheme. But, SOAP itself is a protocol.
SOAP only supports XML, but REST supports different format like text, JSON, XML etc. And we know if we use JSON then definitely we will be in better place in terms of payload.
SOAP can use any generic transport (HTTP / HTTPS) or RPC (Remote Procedural Call). But, REST uses only HTTP/HTTPS
SOAP can’t use REST. But, REST can use SOAP similar to HTTP or any other protocols
SOAP used services interfaces to expose the business logic. REST used URI to expose the business logic
In Java, JAX-WS is for SOAP web services. But, Java JAX-RS is for REST web services
SOAP defines the standards to be strictly followed. REST doesn’t define any standards like SOAP
SOAP requires more bandwidth and resource than REST. REST required less bandwidth and resources.
SOAP defines its own security. REST inherits security measures from underlying transport
SOAP is less preferred these days as compared to REST
RESTful and SOAP WebServices are fundamentally different.
In short - SOAP is a typical RPC based call where you hide your request action and details within the XML document of the SOAP body. Wheras pure RESTful webservie totally rely on HTTP methods to perform an action on server.
Although WADL is not yet widely adopted and not really a standard but the theory behind it is to simply help tools to generate some code, and it aims to promote reuse of applications beyond the basic use in a web browser i.e. machine-to-machine communication (still using HTTP protocol).
Is there any way to consume a SOAP based Spring web service without generating stubs on the client (as suggested by umpteen threads pointing to JAX-WS)?
Here is my complete scenario:
I have 2 web applications, say APP1 & APP2, both of which have Spring support. APP2 exposes it's APIs as Spring-WS that accept POJOs (Reqeust and Response objects) via. SOAP. Now, I want to call these web services from APP1, but would like to avoid having to create stubs using the WSDL frmo APP2. Is this possible?
For more detail, here is one of my web service's operation:
#PayloadRoot(localPart = "CreateNewRequest", namespace = "myNameSpace")
public CreateNewReqResponse createNewRequest( CreateNewReqRequest requestObj ) throws Exception
{
NewCase newCase = this.localSpringService.createNewCase( requestObj.getParam1(), requestObj.getParam2() );
CreateNewReqResponse response = this.objectFactory.createCreateNewReqResponse();
CreateNewReqResponseObject responseObject = this.objectFactory
.createCreateNewReqResponseObject();
if( null != newCase )
{
responseObject.setParam1( newCase.getParam1() );
responseObject.setParam2( newCase.setParam2() );
}
responseObject.setCaseRequestedDate( caseRequestedDate );
}
response.setResponseObject( responseObject );
return response;
}
Now, as you can see, the web service method accepts CreateNewReqRequest and returns CreateNewReqResponse. What I am trying to figure out is how can I call this web service from APP1, which does not have any clue about these classes - CreateNewReqRequest and CreateNewReqResponse? Is there no other way other than creating stubs in APP1 (from the WSDL) using JAX-WS?
Both the applications in question are our own (that is we have developed them) but run on different servers, because of which APP1 can not call the web service directly - cross-domain policy. Hence, I will writing a servlet in APP1 which will consume the web service exposed by APP2.
At the end of they day SOAP is simple a protocol on top of HTTP. So if you wish to forgo the usage of JAX-WS, you could start using raw http connections and hand code the SOAP requests and manually parse the SOAP Response on your own. This would simply mean you are re - inventing the wheel which is JAX-WS Client stubs.
So If you absolutely want to avoid Stub creation, have a go it at with HTTP post and get Messages at the WSDL end point URL.
What the client Stub does is simply abstract out that implementation for you. i.e. you will not have to deal with nitty gritty of SOAP/WSDL and http connection, you would be dealing with SOAP at a higher level, i.e through Java Objects.
You could also look into other libraries such as Apache CXF or Axis, but even there you will have to generate client stubs.
Thus the question you want to ask is, Do you want to really go in and manually muck around with http connections and SOAP XMLs or let the a framework take do that grunt work for you.
Reply to Nitin's comment follows below
To answer your questions, 1. Yes you will have to re-create the stubs if the WSDL changes, if you are not using the stubs but parsing everything manually you will have to change that code. So effectively there is no difference between the two. Your program will have to change if the WSDL (i.e. the contract between client and service) changes. This would be same even for REST, i.e. if the contract published by the service changes(Maybe the parameters, or the action etc), you will have to Change your client code. There is no escaping that. Hopefully, the public Webservices would have been designed in such a way to allow future modification, and such modifications wouldn't happen overnight thus giving you enough time to modify your code. This issue has nothing to do with how the web service has been implemented i.e. Spring Web Service has nothing to do with.
You seem to be missing the point of the Client stubs that a SOAP framework like JAX-WS, Axis, CXF generate for you. The Client Stub is one way to talk to the Web service. It is not the only way. The Client stub is the preferred method, because it abstracts outout the nitty gritties of handling SOAP calls manually. So, rather then you re inventing the wheel and implementing a SOAP(XML) parsing library, you can concentrate your efforts on the actual application that you are writing. In your actual program you would only have to deal with POJOs and never have to worry about how the SOAP magic happens i.e. how to convert your data and package it up in a SOAP message, send that SOAP Message to the Service using a HTTP connection, handle the response, Parse the response SOAP Message and retrieve the data you care about. All of this you avoid by using the POJOs. You set the properties for request, make a method call to the client stub service method, and recieve an object, everything else is you don't have to worry about (ideally).
I hope this clear things up a bit.
Take a look at WebServiceTemplate class.