Introduction to XML-RPC Web service protocol [i]

XML-RPC is a cross-platform, remote invocation protocol that is suitable for transmission over the Internet. The client sends a POST request to the server via the HTTP protocol, the post data is encoded with XML, the server receives the request, extracts the post data, gets the calling method and parameters, then executes, and finally returns the result of the XML format.

With XML-RPC protocol, different servers can communicate with each other and call remote procedures. Simpler than SOAP,XML-RPC, and more suitable for web development.

A simple XML-RPC request

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>

It's easy to understand even if it's never touched: Examples.getstatename is a remote calling method, 41 is a call parameter, and the server location is BETTY.USERLAND.COM/RPC2

Send Header requirements:

1, the path after post is not required, if the server only processes XML-RPC requests, this can be omitted; If the server also processes HTTP requests, the server's path should be fully filled.

2, User-agent and host must be specified.

3, Content-type must be text/xml format.

4, the number of bytes sent must be specified, and must be correct.

5, other header information can be added as needed.

PHP is easy to implement $xml = "Some request in XML format"; Request data
$fp = fopen ($host, $port, $error, $ERRSTR, 10);
if ($error)
Die ($ERRSTR);
Fwrite ($fp, "post/http1.1");
Fwrite ($fp, "User-agent:xml-rpc Client");
Fwrite ($FP, "Host: $host");
Fwrite ($fp, "content-type:text/xml");
Fwrite ($FP, "Content-length:". Strlen ($xml). " " );
while ($data = Fread ($fp, 1024)) {
Do something here
}
Fclose ($FP);

The XML request has only one root element <methodcall>, immediately after the root element is the calling method name <methodname>, indicating the remote procedure to invoke, and finally the argument list. The parameter list starts with <params>, with each parameter under <param> included. Parameter must indicate a numeric type, if not indicated, the default is string type. The simple types that can be supported are int (or I4), Boolean, String, base64, double, datetime.iso8601, complex data types support array arrays and struct struct types, if you want to transfer data for an object type, you must first convert the object to a struct type, and then export the object's properties to struct.

struct type: < struct >
    < member >
       < name > lowerbound </name >
       < value >< i4 > </i4 ></ Value >
     </member >
    < member >
        < name > upperbound </name >
       < value >< I4 > 139 </i4 ></value >
     </member >
  </struct >

  Array Type:   < array >
    < data >
       < value >< I4 > </i4 ></value >
       < value >< String > Egypt </string ></value >
       < value >< Boolean & Gt 0 </Boolean ></value >
       < value >< I4 > -31 </I4 ; </value >
      </data >
  </array >   Complex data types can be nested on each other: < struct >
    < member >
       < name > Lowerbound &L t;/name >
       < value >< i4 > </i4 ></value >
&N bsp;      </>
    < member >
     &n