Is it possible to take the whole post String as the parameter in rest api method?

Question

I have gone through some documents like: https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_rest_methods.htm .

It seems to me that in order to write a post API interface I need to understand what the input string is. But my scenario is the input json string can be dynamic.

Is there a way for me to take the whole post string as the parameter and handle that json string dynamically in my function? Something like:

@HttpPost
global static void doPost(String message) 
{
    //...

Not quite sure whether this is possible though.

Answer 1

You can capture the whole request body as the string from Restrequest

@HttpPost
 global static void doPost(){
    RestRequest req = RestContext.request;
    string jsonbody =   req.requestBody.toString();
    //Use deserializer via maps here
    Map<String, Object> m = (Map<String, Object>)JSON.deserializeUntyped(jsonbody);

 }

The above can be used and any valid JSON can be passed in the request body .