OAuth 2.0 客户端，第 2 部分: 客户端凭据授权

POST /token HTTP/1.1
Host: server.example.com
Authorization:Basic czZCaGRSa3F0MzpnWDFmQmF0M2JW
Content-Type: application/x-www-form-urlencoded
grant_type=client_credentials&client_id=myApp&client_secret=ab32vr

HTTP/1.1 200 OK
Content-Type: application/json;charset=UTF-8
Cache-Control: no-store
Pragma: no-cache
{"access_token":"2YotnFZFEjr1zCsicMWpAA","token_type":"example","expires_in":3600,"example_parameter":"example_value"
}

//Load the properties file
Properties config = OauthUtils.getClientConfigProps(OauthConstants.CONFIG_FILE_PATH);//Generate the OAuthDetails bean from the config properties file
Oauth2Details oauthDetails = OauthUtils.createOauthDetails(config);//Validate Input
if(!OauthUtils.isValidInput(oauthDetails)){System.out.println("Please provide valid config properties to continue.");System.exit(0);
}//Determine operation
if(oauthDetails.isAccessTokenRequest()){//Generate new Access tokenString accessToken = OauthUtils.getAccessToken(oauthDetails);if(OauthUtils.isValid(accessToken)){System.out.println("Successfully generated Access token forclient_credentials grant_type:"+accessToken);}else{System.out.println("Could not generate Access token forclient_credentials grant_type");}
}else {//Access protected resource from server using OAuth2.0//Response from the resource server must be in Json or Urlencoded or xmlSystem.out.println("Resource endpoint url:" + oauthDetails.getResourceServerUrl());System.out.println("Attempting to retrieve protected resource");OauthUtils.getProtectedResource(oauthDetails);
}

String resourceURL = oauthDetails.getResourceServerUrl();HttpGet get = new HttpGet(resourceURL);
get.addHeader(OAuthConstants.AUTHORIZATION,getAuthorizationHeaderForAccessToken(oauthDetails.getAccessToken()));
DefaultHttpClient client = new DefaultHttpClient();
HttpResponse response = null;
int code = -1;try {response = client.execute(get);code = response.getStatusLine().getStatusCode();if (code == 401) {// Access token is invalid or expired.Regenerate the access// tokenSystem.out.println("Access token is invalid or expired.Regenerating access 	  token....");String accessToken = getAccessToken(oauthDetails);if (isValid(accessToken)) {// update the access token// System.out.println("New access token:" + accessToken);oauthDetails.setAccessToken(accessToken);get.removeHeaders(OAuthConstants.AUTHORIZATION);get.addHeader(OAuthConstants.AUTHORIZATION,getAuthorizationHeaderForAccessToken(oauthDetails.getAccessToken()));get.releaseConnection();response = client.execute(get);code = response.getStatusLine().getStatusCode();if (code == 401) {throw new RuntimeException("Could not access protected resource.Server returned http 	  code:" + code);}}else {throw new RuntimeException(Could not regenerate access token");}}handleResponse(response);

 HttpPost post = new HttpPost(oauthDetails.getAuthenticationServerUrl());String clientId = oauthDetails.getClientId();String clientSecret = oauthDetails.getClientSecret();String scope = oauthDetails.getScope();List<BasicNameValuePair> parametersBody =new ArrayList<BasicNameValuePair>();parametersBody.add(new BasicNameValuePair(OAuthConstants.GRANT_TYPE,oauthDetails.getGrantType()));parametersBody.add(new BasicNameValuePair(OAuthConstants.Client_ID,clientId));parametersBody.add(new BasicNameValuePair(OAuthConstants.Client_Secret,clientSecret));if (isValid(scope)) {parametersBody.add(new BasicNameValuePair(OAuthConstants.SCOPE,scope));}DefaultHttpClient client = new DefaultHttpClient();HttpResponse response = null;String accessToken = null;try {post.setEntity(new UrlEncodedFormEntity(parametersBody,HTTP.UTF_8));response = client.execute(post);int code = response.getStatusLine().getStatusCode();if (code == 401) {System.out.println("Authorizationserver expects Basic authentication");// Add Basic Authorization headerpost.addHeader(OAuthConstants.AUTHORIZATION,getBasicAuthorizationHeader(oauthDetails.clientId,clientSecret));System.out.println("Retry with client credentials");post.releaseConnection();response = client.execute(post);code = response.getStatusLine().getStatusCode();if (code == 401) {throw new RuntimeException("Could not retrieve access token for client:"clientId);}}}Map<String, String> map = handleResponse(response);accessToken = map.get(OAuthConstants.ACCESS_TOKEN);} catch (ClientProtocolException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}return accessToken;

Resource server URL is null.Will assume request is for generating Access token
Validated Input********** Response Received **********expires_in = 3600token_type = bearerscope =access_token = mc20Tn3Br8raUvCrBEap3VYMbErGXshjiXYFAwEB
Successfully generated Access token for client_credentials grant_type:
mc20Tn3Br8raUvCrBEap3VYMbErGXshjiXYFAwEB

Resource endpoint url: https://localhost/protectedResource
Attempting to retrieve protected resource********** Response Received **********
{"Author":"Varun Ojha","Authenticatation":"Oauth2.0","Result":"Success"
}