从SOAP到REST

Question

I have a bunch of WCF SOAP services that serve my WP7 apps. Now I'm writing Android versions of those WP7 apps but SOAP support is practically nonexistent in Android so I must use REST for these Android apps.

So, my plan is to duplicate my WCF SOAP services in ASP.NET Web API. I am new to RESTful services.

Now that I'm getting into the details I think I'm appreciating SOAP a little more.

For instance one of my SOAP methods takes, among other arguments, a "TripLocker_s" object. (SOAP definition pasted below). As you can see a TripLocker_s object is an array TripLegModel_s objects. My various service methods pass all sorts of complex objects as arguments.

When I review any Android tutorials having to do with using HTTP services, nothing more complex than a string and maybe an integer is ever discussed as an argument. I can't find any information on passing complex objects.

How do I pass complex objects as arguments with Web api? Is there a way, for instance, to take a TripLocker_s object and serialize it as http parms (and then back again on the server?)

Thanks, Gary

    [DataContract]
public class TripLegModel_s
{
    [DataMember]
    public string ourDirection;  //SE, SW, SSW, etc.
    [DataMember]
    public double longitude;
    [DataMember]
    public double latitude;
    [DataMember]
    public double altitude;
    [DataMember]
    public DateTimeOffset TimeStamp;
    [DataMember]
    public double speed;
}

[DataContract]
public class TripLocker_s
{
    [DataMember]
    public ObservableCollection<TripLegModel_s> BreadCrums = new ObservableCollection<TripLegModel_s>();

Thanks,

Answer 1

No reason you can't pass complex objects as JSON or XML in RESTful APIs via RESTful (http) verbs (get, post, put, etc...). JSON is more web (javascript) friendly and RESTful/hypermedia APIs are typically chosen for web apps. Since it's so web friendly, if you choose it for mobile android consumption the API is also more consumable for web, iOS, win phone etc... Javascript (and therefore JSON) is becoming the language of choice for the web.

If you're creating, you post the serialized object in the body.
See this post for a full example: restful-like CRUD operation url pattern for nested model

If you're using WCF, consider webapi, see http://www.asp.net/web-api

Specifically, checkout: http://www.asp.net/web-api/overview/creating-web-apis/creating-a-web-api-that-supports-crud-operations

For example, in the webapi CRUD sample, it works with a products object:

namespace ProductStore.Models
{
    public class Product
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string Category { get; set; }
        public decimal Price { get; set; }
    }
}

Finally, checkout this read on thinking more RESTful (as opposed to RPC or SOAP) http://blog.steveklabnik.com/posts/2011-07-03-nobody-understands-rest-or-http

Answer 2

RE: "My plan is to duplicate my WCF SOAP services in ASP.NET Web API."

SUGGESTION: Don't even think about it! There's no need ... you should be able to create REST-based web services just fine. That's where the world is going ... and Microsoft is going along with it. It should't be an issue.

And please don't get hung up on "everything's gotta be an object". It DOESN'T . In particular, why bog down your Android app with an (arguably unnecessary) GSON library, if a simple JSON message will work just as well?

Also, if you're not currently a "Java Guy", you might want to consider coding your Android stuff in a higher-level framework like PhoneGap:

• http://www.phonegap.com

Just a suggestion!

Answer 3

1) Why can't you use SOAP if you want to? What specific problems are you having?

2) Why would anybody want to use SOAP if they could use REST instead?

3) Are you familiar with JSON ?

Your Android is a web service client, correct? What/where is the web service itself, and is it using SOAP, JSON or "something else"?

Please check out this instructive tutorial on REST:

• http://www.ibm.com/developerworks/webservices/library/ws-restful/

These other links might be useful:

• JSON Tutorial

• Creating a REST Webservice for an Android Client

• Getting started with JSON