final String FACEBOOK_APP_ID_NAME = "com.facebook.sdk.ApplicationId";
        final String facebookAppIdValue = getEnvironment().getAndroidManifest().getMetaDataQualifiedNames().get(FACEBOOK_APP_ID_NAME);
        if (facebookAppIdValue == null) {
            valid.addError( 
                    "Your application must include the meta-data named " + FACEBOOK_APP_ID_NAME + "." + 
                    "\nEx. <meta-data android:name=\"com.facebook.sdk.ApplicationId\"" +
                    "\n             android:value=\"<Your Facebook App Id>\"/>"
                );
        }

        final String FACEBOOK_LOGIN_ACTIVITY_NAME = "com.facebook.LoginActivity";
        if (!getEnvironment().getAndroidManifest().getComponentQualifiedNames().contains(FACEBOOK_LOGIN_ACTIVITY_NAME)) {
            valid.addError( 
                    "Your application must declare " + FACEBOOK_LOGIN_ACTIVITY_NAME + " activity." + 
                    "\nEx. <activity android:name=\"com.facebook.LoginActivity\"/>"
                );
        }