Võrgurakenduste protokollid 1

Http

The web protocol: how to send web data over the TCP connection. Read this detailed intro.

Small example (from the intro above):

Request:

    GET /path/file.html HTTP/1.0
    From: someuser@jmarshall.com
    User-Agent: HTTPTool/1.0
    [blank line here]

The server should respond with something like the following, sent back through the same socket:

    HTTP/1.0 200 OK
    Date: Fri, 31 Dec 1999 23:59:59 GMT
    Content-Type: text/html
    Content-Length: 1354

    <html>
    <body>
    <h1>Happy New Millennium!</h1>
    (more file contents)
      .
      .
      .
    </body>
    </html>

Get and post

GET: all data sent is in the headers & URL. If your form has METHOD="GET" in its FORM tag, your CGI program will receive the encoded form input in the environment variable QUERY_STRING.

POST: when sending, after headers comes text. If your form has METHOD="POST" in its FORM tag, your CGI program will receive the encoded form input on stdin. The server will NOT send you an EOF on the end of the data, instead you should use the environment variable CONTENT_LENGTH to determine how much data you should read from stdin.

Read:

• get and post details
• additionally: post in ajax

Post answer reading example:

 if (getenv("CONTENT_LENGTH") == NULL ||
      sscanf(getenv("CONTENT_LENGTH"), "%d", &cl) != 1) {   
    data_error(NULL,"bad http format or missing content length received");      
    return 1;   
  }                   
  // Create space for content: 
  xmlquerybuf = malloc(cl + 1);
  if (xmlquerybuf == NULL) {
    data_error(NULL,"cannot malloc for http request: bad content length?");
    return 1;
  }
  // Read content:    
  c='a';
  for(i=0; i<cl && c!=EOF; i++) {
   c=fgetc(stdin);
   xmlquerybuf[i]=c; 
  }  
  xmlquerybuf[i]=0;

Json

JSON details and official spec:

• http://en.wikipedia.org/wiki/JSON
• www.json.org
• http://tools.ietf.org/html/rfc4627

JSON-RPC: http://json-rpc.org/wiki/specification

xml-rpc

Read: http://www.xmlrpc.com/

Call example:

POST /RPC2 HTTP/1.0
User-Agent: Frontier/5.1.2 (WinNT)
Host: betty.userland.com
Content-Type: text/xml
Content-length: 181

<?xml version="1.0"?> 
 <methodCall> 
       <methodName>examples.getStateName</methodName> 
       <params> 
           <param> <value><i4>41</i4></value> </param> 
      </params> 
  </methodCall> 

SOAP

Read in this order:

• wikipedia
• w3schools micro-tutorial
• w3c primer

Small recent example from xTee:

Request:

<soapenv:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xtee="http://x-tee.riik.ee/xsd/xtee.xsd" xmlns:ehis="http://producers.ehis.xtee.riik.ee/producer/ehis">
   <soapenv:Header>
      <xtee:id xsi:type="xsd:string">680e0c731a244e2c91210e1540458441</xtee:id>
      <xtee:nimi xsi:type="xsd:string">ehis.idpilet</xtee:nimi>
      <xtee:isikukood xsi:type="xsd:string">10101010101</xtee:isikukood>
      <xtee:andmekogu xsi:type="xsd:string">ehis</xtee:andmekogu>
      <xtee:asutus xsi:type="xsd:string">10747013</xtee:asutus>
   </soapenv:Header>
   <soapenv:Body>
      <ehis:idpilet soapenv:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
         <keha xsi:type="ehis:EHIS_Isikukood">10101010101</keha>
      </ehis:idpilet>
   </soapenv:Body>
</soapenv:Envelope>

Answer:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <soapenv:Body>
      <ns1:idpiletResponse soapenv:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" xmlns:ns1="http://producers.ehis.xtee.riik.ee/producer/ehis">
         <paring xsi:type="ns1:EHIS_Isikukood">10101010101</paring>
         <keha xsi:type="ns1:EHIS_Boolean">ei</keha>
      </ns1:idpiletResponse>
   </soapenv:Body>
</soapenv:Envelope>

XML Schema

Read in this order:

• wikipedia
• w3schools micro-tutorial
• w3c primer