Question

I am creating a Web Service that will handle incoming request properly (I knew, it is a description) I found some sample code which present SOAP WS and looks like:

    @SoapAction("some fine url")
    @ResponsePayload
    public CertResponse  getCert(@RequestPayload Cert param) 
    {...}

It takes Cert object from request and manages it properly. I want to do it in the REST approach and I changed this class to look like:

    @RequestMapping(value="getCert", method = RequestMethod.POST)
    @ResponseBody
    public CertResponse  getCert(@RequestBody Cert param) 
    {...} 

But I have no idea how or even if it is possible to write a client that can send object through HTTP Post.

Can anyone give me a hint how can i send object Cert? Or if i have to stay with @SoapAction what should I do to make it work? I guess removing @Controller is not enough.

Answer 1

In SOAP approach, there is a well defined way to convert each class object to SOAP formatted XML. Thus, there is no effort.

If you will use RESTful approach, you have to describe how your Cert or CertResponse objects will be written to/read from the response/request.

Basically you have three options:

1. Use JSON or XML or plain String. Convert your Web service descriptor so that the request and response are one of those (JSON, XML, String). Then your getCert method should convert the request to Cert object, prepare your response as CertResponse object and convert it to an appropriate response type.

2. Leave your getCert method as is. But you need to specify “how Cert objects are read from request” and “how CertResponse objects are written to response” You need to define classes that extend interfaces MessageBodyReader and MessageBodyWriter. In these classes a similar conversion logic should be implemented that converts your objects to/from JSON or XML or String.

   In any of these two options you need to implement two things : A method that converts JSON/XML/String to Cert, a method that converts CertResponse object to JSON/XML/String.

   You can do a text based implementation, which parses/constructs the request/response by text processing and uses String class only. Or you can use some library such as JSON library with JSONObject class, or Java SAX or DOM based XML libraries that come with the Java bundle.

3. Check out for application frameworks such as Spring. They might provide ways to automatically convert your objects to JSON or XML, reducing the programming effort necessary.