Create FacebookCustomApi

src/main/java/org/mamute/auth/FacebookCustomApi

@@ -0,0 +1,104 @@
+package org.mamute.auth;
+
+import org.codehaus.jettison.json.JSONObject;
+import org.scribe.builder.api.DefaultApi20;
+import org.scribe.exceptions.OAuthException;
+import org.scribe.extractors.AccessTokenExtractor;
+import org.scribe.model.OAuthRequest;
+import org.scribe.oauth.OAuth20ServiceImpl;
+import org.scribe.oauth.OAuthService;
+import org.scribe.utils.OAuthEncoder;
+import org.scribe.utils.Preconditions;
+import org.scribe.model.*;
+
+public class FacebookCustomApi extends DefaultApi20 {
+
+    private static final String AUTHORIZE_URL           = "https://www.facebook.com/dialog/oauth?response_type=code&client_id=%s&redirect_uri=%s";
+    private static final String SCOPED_AUTHORIZE_URL    = AUTHORIZE_URL + "&scope=%s";
+
+    @Override
+    public String getAccessTokenEndpoint() {
+        return "https://graph.facebook.com/oauth/access_token";
+    }
+
+    @Override
+    public AccessTokenExtractor getAccessTokenExtractor() {
+        return new AccessTokenExtractor() {
+
+            @Override
+            public Token extract(String response) {
+
+                Preconditions.checkEmptyString(response, "Response body is incorrect. Can't extract a token from an empty string");
+                try {
+                    //Here is the real deal, Just create the JSON from response and get the access token from it
+                    JSONObject json = new JSONObject(response);
+                    String token = json.getString("access_token");
+
+                    return new Token(token, "", response);
+                } catch (Exception e){
+                    throw new OAuthException("Response body is incorrect. Can't extract a token from this: '" + response + "'", null);
+                }
+            }
+        };
+    }
+
+    @Override
+    public String getAuthorizationUrl(OAuthConfig config) {
+        // Append scope if present
+        if (config.hasScope()) {
+            return String.format(SCOPED_AUTHORIZE_URL, config.getApiKey(),
+                    OAuthEncoder.encode(config.getCallback()),
+                    OAuthEncoder.encode(config.getScope()));
+        } else {
+            return String.format(AUTHORIZE_URL, config.getApiKey(),
+                    OAuthEncoder.encode(config.getCallback()));
+        }
+    }
+
+    @Override
+    public Verb getAccessTokenVerb() {
+        return Verb.POST;
+    }
+
+    @Override
+    public OAuthService createService(OAuthConfig config) {
+        return new FacebookOAuth2Service(this, config);
+    }
+
+    private class FacebookOAuth2Service extends OAuth20ServiceImpl {
+
+        private static final String GRANT_TYPE_AUTHORIZATION_CODE   = "authorization_code";
+        private static final String GRANT_TYPE                      = "grant_type";
+        private DefaultApi20 api;
+        private OAuthConfig config;
+
+        public FacebookOAuth2Service(DefaultApi20 api, OAuthConfig config) {
+            super(api, config);
+            this.api    = api;
+            this.config = config;
+        }
+
+        @Override
+        public Token getAccessToken(Token requestToken, Verifier verifier) {
+            OAuthRequest request = new OAuthRequest(api.getAccessTokenVerb(), api.getAccessTokenEndpoint());
+            switch (api.getAccessTokenVerb()) {
+                case POST:
+                    request.addBodyParameter(OAuthConstants.CLIENT_ID, config.getApiKey());
+                    request.addBodyParameter(OAuthConstants.CLIENT_SECRET, config.getApiSecret());
+                    request.addBodyParameter(OAuthConstants.CODE, verifier.getValue());
+                    request.addBodyParameter(OAuthConstants.REDIRECT_URI, config.getCallback());
+                    request.addBodyParameter(GRANT_TYPE, GRANT_TYPE_AUTHORIZATION_CODE);
+                    break;
+                case GET:
+                default:
+                    request.addQuerystringParameter(OAuthConstants.CLIENT_ID, config.getApiKey());
+                    request.addQuerystringParameter(OAuthConstants.CLIENT_SECRET, config.getApiSecret());
+                    request.addQuerystringParameter(OAuthConstants.CODE, verifier.getValue());
+                    request.addQuerystringParameter(OAuthConstants.REDIRECT_URI, config.getCallback());
+                    if (config.hasScope()) request.addQuerystringParameter(OAuthConstants.SCOPE, config.getScope());
+            }
+            Response response = request.send();
+            return api.getAccessTokenExtractor().extract(response.getBody());
+        }
+    }
+}