How to get google adwords reports in salesforce? -

hi developing application in salesforce accessing google adwords reports data e.g. adgroup_performance_report. sending http post request https://adwords.google.com/api/adwords/reportdownload/v201302, , using apex(java language in salesforce) below request.

http h = new http(); httprequest req = new httprequest(); googleauthorization auth=new googleauthorization(); req.setheader('authorization', 'googlelogin ' + auth.token); req.setheader('useragent', 'xxxxx'); req.setheader('developertoken','xxxxxxxx'); req.setheader('clientcustomerid','xxxxxxxx'); req.setendpoint('https://adwords.google.com/api/adwords/reportdownload/v201302'); req.setheader('content-type', 'application/x-www-form-urlencoded'); req.setmethod('post'); string xml='<reportdefinition xmlns="https://adwords.google.com/api/adwords/cm/v201302">'+           '<selector>'+             '<fields>campaignid</fields>'+             '<fields>id</fields>'+             '<fields>impressions</fields>'+             '<fields>clicks</fields>'+             '<fields>cost</fields>'+             '<predicates>'+               '<field>status</field>'+               '<operator>in</operator>'+               '<values>enabled</values>'+               '<values>paused</values>'+             '</predicates>'+           '</selector>'+           '<reportname>custom adgroup performance report</reportname>'+           '<reporttype>adgroup_performance_report</reporttype>'+           '<daterangetype>last_7_days</daterangetype>'+           '<downloadformat>xml</downloadformat>'+         '</reportdefinition>'; req.setbody('__rdxml='+encodingutil.urlencode(xml, 'utf-8')); httpresponse res=h.send(req); 

after requesting getting authenticationerror system.httpresponse[status=bad request, statuscode=400].

 <?xml version="1.0" encoding="utf-8" standalone="yes"?><reportdownloaderror><apierror><type>authenticationerror.user_id_invalid</type><trigger>&lt;null&gt;</trigger><fieldpath></fieldpath></apierror></reportdownloaderror> 

however loginid , password correct. doing wrong can please help!

check app's configuration. must have there :

<adwordsapi>     <add key="maskcredentials" value="true" />     <add key="enablegzipcompression" value="true" />     <add key="proxyserver" value="" />     <add key="proxyuser" value="" />     <add key="proxypassword" value="" />     <add key="proxydomain" value="" />     <add key="useragent" value="*******" />     <add key="developertoken" value="*******" />     <add key="clientcustomerid" value="*******" />     <add key="skipreportheader" value="false" />     <add key="skipreportsummary" value="false" />     <add key="oauth2clientid" value="*******" />     <add key="oauth2clientsecret" value="*******" />     <add key="oauth2mode" value="application" />     <add key="oauth2refreshtoken" value="1/*******" /> </adwordsapi> 

fill required values *****.