如何发送/接收JSON？

Question

A dumb question, I know. But I don't normally do web programming and have been asked to send some JSON data and receive some in return.

I googled and it is clear how to encode and decode the JSON data, but I am so new to this that I don't know how to communicate with the given URL and say "here's some data, please send me some back".

Can anyone point me at a simple working code example? For instance, just to pass user_name and password as JSON and to receive some reply ... I think I should be using TIdHTTP , but am not sure how to use it with JSON. I have one GET and one POST interface.

+1 to @DavidHeffernan but I don't understand who to pass the packed JSON data with my request or to retrieve it from the response. En/de-code is fine, but adding it as parameters has me bogged down.

I really would appreciate a (link to a) small, but complete working example.

Btw, I only have XE2 starter edition, so I don't have datasnap.

Answer 1

For the JSON process via HTTP, take a look at the following S/O question: https://stackoverflow.com/a/15948106/458259

If your problem is about how to consume a remote RESTful service in Delphi, you will find it the answer.

But if you want to communicate between Delphi applications using JSON and HTTP, the easiest is to implemenent a RESTful Client-Server connection in Delphi.

For Client-Server transmission using JSON and RESTful, take a look at our Open Source Synopse mORMot framework . It will do all the JSON serialization and RESTful routing for you.

It features a Client-Server ORM (perhaps not what you need here).

But also a SOA framework using two modes:

• Method-based services, like DataSnap ;
• Interface-based services, like WCF .

You can chose either mode to use JSON communication over HTTP.

Note that mORMot is expected to work with Delphi XE2 starter edition , since it does not use any "advanced" feature of the Pro/Entreprise/Architect editions, like DB.pas or DataSnap. And it will allow you to access databases, even with a starter edition. In case of difficulties due to something missing in the Starter, please feel free to report the problem on our forum.