org.springframework.web.client.HttpClientErrorException: 401 Authorization Required
	at org.springframework.web.client.DefaultResponseErrorHandler.handleError(DefaultResponseErrorHandler.java:91)
	at org.springframework.web.client.RestTemplate.handleResponse(RestTemplate.java:641)
	at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:597)
	at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:572)
	at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:493)
	at org.springframework.social.oauth1.OAuth1Template.exchangeForToken(OAuth1Template.java:187)
	at org.springframework.social.oauth1.OAuth1Template.exchangeForAccessToken(OAuth1Template.java:132)
	at com.vaadin.frontend.spring.security.authentication.twitter.TwitterAuthInfo.exchangeForAccessToken(TwitterAuthInfo.java:51)
	at com.vaadin.frontend.spring.security.authentication.twitter.TwitterAuthInfo.getPerson(TwitterAuthInfo.java:58)
	at com.vaadin.frontend.spring.security.authentication.twitter.TwitterAuthenticationToken.getPrincipal(TwitterAuthenticationToken.java:26)
	at com.vaadin.frontend.spring.security.authentication.twitter.TwitterAuthenticationProvider.authenticate(TwitterAuthenticationProvider.java:29)
	at org.springframework.security.authentication.ProviderManager.authenticate(ProviderManager.java:174)
	at com.vaadin.frontend.spring.security.authentication.twitter.TwitterAuthFilter.attemptAuthentication(TwitterAuthFilter.java:36)
	at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:218)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
	at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:206)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
	at org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter.doFilter(RememberMeAuthenticationFilter.java:150)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
	at com.vaadin.frontend.spring.security.authentication.RequestResponseReferenceFilter.doFilter(RequestResponseReferenceFilter.java:29)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
	at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:214)
	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:177)
	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)
	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1613)
	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:541)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
	at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:190)
	at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1584)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:188)
	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1228)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:168)
	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:481)
	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1553)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:166)
	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1130)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
	at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:213)
	at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:118)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
	at org.eclipse.jetty.server.Server.handle(Server.java:564)
	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:318)
	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:251)
	at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:279)
	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:112)
	at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:124)
	at org.eclipse.jetty.util.thread.Invocable.invokePreferred(Invocable.java:122)
	at org.eclipse.jetty.util.thread.strategy.ExecutingExecutionStrategy.invoke(ExecutingExecutionStrategy.java:58)
	at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.produceConsume(ExecuteProduceConsume.java:201)
	at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.run(ExecuteProduceConsume.java:133)
	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:672)
	at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:590)
	at java.lang.Thread.run(Thread.java:745)