Originally posted by: sashok

http://www.midrangenews.com/view?id=2376&p=9

This package allows GET, PUT, POST from within RPG.

Originally posted by: dxd

if the HMC is using its self-signed certificate you'll likely need to first export the HMC cert  from a browser then import to the IBM i default java keystore. 
 keytool -import -v -trustcacerts -alias icr9 -file /icr9.rchland.ibm.com -key
 store /QOpenSys/QIBM/ProdData/JavaVM/jdk70/32bit/jre/lib/security/cacerts    

default pwd:  changeit

Here's an example of the login and a simple query:

SELECT varchar(responseMsg,2048), varchar(responseHttpHeader,1024)
 from table(  systools.HTTPPUTCLOBVERBOSE('https://icr9.rchland.ibm.com:12443/rest/api/web/Logon',
CAST ('<httpHeader>
       <header name="Content-Type" value="application/vnd.ibm.powervm.web+xml; type=LogonRequest"/>
       <header name="Accept" value="application/vnd.ibm.powervm.web+xml; type=LogonResponse"/>
       </httpHeader>' AS CLOB(1K)),
CAST('<?xml version="1.0" encoding="UTF-8" standalone="yes"?>                                                    
<LogonRequest xmlns="http://www.ibm.com/xmlns/systems/power/firmware/web/mc/2012_10/" schemaVersion="V1_0">
  <UserID>hscroot</UserID>                                                                                  
  <Password>abc123</Password>                                                                             
</LogonRequest>'
AS CLOB(10K))  
)) as HMC;

Pass the X-API-Session value from the login reply to the next query.

SELECT varchar(responseMsg,4096), varchar(responseHttpHeader,1024)
 from table(  systools.HTTPGETCLOBVERBOSE('https://icr9.rchland.ibm.com:12443/rest/api/uom/ManagementConsole',
'<httpHeader>
     <header name="Accept" value="application/atom+xml; charset=UTF-8"/>
       <header name="X-API-Session" value="wZ2BHTWSv8FuPu3Lp-mcxMNrFInDZF4lYLRlMAbFGtiGH39pHgPEtbYts6yMSPS4cONApow8w-CNwpl7lAzCI8A9tR4_d-oex53k65JQLbQ_HlVF4zFhZVhFYznetNDvZGsq-0G7aQS0Nzvvhm-kXHvlg_k7TVO1xwy-kciOFJ6tLIXJnjaAphaUeIUIA-DrBeYCJAJnJTmRP2s_oeOtYEhH6xNloJSEv6SVaBHPRTg="  />
       </httpHeader>'
)) as HMC;