SAML2 usage with axis2 web service
Is there any way that i can use SAML to authenticate(SSO) to an Idp using an axis2 web service?
SAML WebBrowser SSO Profile is used to convey an authentication assertion FROM an IdP (identity provider) TO a SP (service provider), which may result in authentication occurring at the SP. SAML SSO isn't used to perform authentication to an IdP. An SP can send an authentication request (AuthnRequest) to an IdP, but that's simply a request, not the authentication itself. The SAML SSO profile allows for AuthnRequest over HTTP (Redirect/POST/Artifact) and Response (the authentication assertion from the IdP) over HTTP (POST/Artifact). If IdP supports/uses HTTP Artifact, then the authentication assertions would be obtained by calling a web service at the IdP, rather than being conveyed directly in the response XML.
Perhaps you should look at the Enhanced Client or Proxy (ECP) profile, which uses Reverse SOAP (PAOS). This certainly would be possible with Axis2, although to be clear, the web service itself would live at the IdP.
Which end are you implementing, IdP or SP?
You could try using the saml library opensaml http://www.opensaml.org/ to generate your authnRequest and process the response sent by the idp.