idHTTP Sample code delphi XE

Indy 10.6 HTTPS POST example with JSON body

The Indy (Internet Direct) TIdHTTP now creates a default SSLIOHandler when requesting an HTTPS url. This makes TIdHTTP a little easier to use “out of the box”. (blog article).

The code below sends a hard-coded JSON object as POST body to a secure url. Note: if you need to customize the SSLVersions used, or specify certificates/keys, or use status/password event handlers, then you will still have to explicitly assign an SSLIOHandler component to the TIdHTTP.IOHandler property before sending an HTTPS request.

1. uses
2.   IdHTTP, IdGlobal, SysUtils, Classes;
3.  
4. var
5.   HTTP: TIdHTTP;
6.   RequestBody: TStream;
7.   ResponseBody: string;
8. begin
9.   HTTP := TIdHTTP.Create;
10.   try
11.     try
12.       RequestBody := TStringStream.Create('{"日本語":42}',
13.         TEncoding.UTF8);
14.       try
15.         HTTP.Request.Accept := 'application/json';
16.         HTTP.Request.ContentType := 'application/json';
17.         ResponseBody := HTTP.Post('https://httpbin.org/post',
18.           RequestBody);
19.         WriteLn(ResponseBody);
20.         WriteLn(HTTP.ResponseText);
21.       finally
22.         RequestBody.Free;
23.       end;
24.     except
25.       on E: EIdHTTPProtocolException do
26.       begin
27.         WriteLn(E.Message);
28.         WriteLn(E.ErrorMessage);
29.       end;
30.       on E: Exception do
31.       begin
32.         WriteLn(E.Message);
33.       end;
34.     end;
35.   finally
36.     HTTP.Free;
37.   end;
38.   ReadLn;
39.   ReportMemoryLeaksOnShutdown := True;
40. end.

Notes:

• you must not use a TStringList for the POST body. That version of TIdHTTP.Post() formats the data according to the application/x-www-form-urlencoded media type, which is not appropriate for JSON and will corrupt it.
• make sure you encode the JSON body as UTF-8
• Indy will create a SSLIOHander for a URL beginning with https

1. {
2.   "args": {},
3.   "data": "{\"\u65e5\u672c\u8a9e\":42}",
4.   "files": {},
5.   "form": {},
6.   "headers": {
7.     "Accept": "application/json",
8.     "Accept-Encoding": "identity",
9.     "Content-Length": "16",
10.     "Content-Type": "application/json",
11.     "Host": "httpbin.org",
12.     "User-Agent": "Mozilla/3.0 (compatible; Indy Library)"
13.   },
14.   "json": {
15.     "\u65e5\u672c\u8a9e": 42
16.   },
17.   "origin": "*.*.*.*",
18.   "url": "https://httpbin.org/post"
19. }
20.  
21. HTTP/1.1 200 OK