Spring Social Twitter - NPE при разыменовании объекта Twitter

Question

Я использую Spring Social Twitter v. 1.1.0.M4. Я успешно включил соединения в памяти с Twitter. Сейчас я пытаюсь сохранить связь. Соединение с моей базой данных и ведение журнала, кажется, работают, поскольку пользователь аутентифицирован, и я могу видеть его логин в твиттере. Проблема в том, что я не могу получить доступ к их деталям (твиды, подписки и т. Д.). Код, который я имею в своем контроллере для показа твитов пользователя:

@Autowired
private Twitter twitter;

@Autowired
private TwitterConnectionUtils twitterConnectionUtils;

@Autowired
private SessionBean sessionBean;

@RequestMapping("/")
public String index(Model model) {
    logger.warning("index");
    model.addAttribute("sessionBean", sessionBean);
    List<Tweet> tweets = new ArrayList<Tweet>();

    try {
        if (!twitterConnectionUtils.isConnectedToTwitter()) {
            return "index";
        }
        tweets.addAll(twitter.timelineOperations().getHomeTimeline());
    } catch (Exception e) {
        logger.warning(ExceptionUtils.getStackTrace(e));
        model.addAttribute("exception", e.toString());
        return "index";
    }

    model.addAttribute("tweets", tweets);
    return "twitter/tweets";
}

Исключение брошено в линию tweets.addAll(twitter.timelineOperations().getHomeTimeline());, twitter не является нулевым, но в то же время я не могу вызвать какие-либо методы для него (например, toString), потому что я получаю NPE немедленно. Вот трассировка стека ошибки, полученной в logger.warning(ExceptionUtils.getStackTrace(e));:

WARNING: java.lang.NullPointerException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:319)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:131)
at org.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:119)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
at com.sun.proxy.$Proxy16.timelineOperations(Unknown Source)
at agh.sr.tweedle.controller.TweetsController.index(TweetsController.java:43)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:219)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:100)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:604)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:565)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:923)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:778)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:118)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:84)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:103)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:113)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:54)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:183)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:105)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:87)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:192)
at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160)
at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)
at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:259)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:947)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1009)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:724)

Есть идеи, что может быть причиной проблемы? Я также включил мой javaconfig для библиотеки, для справки:

@Configuration
@EnableTwitter(appId="myAppId", appSecret="myAppSecret")
public class TwitterConfig {

    @Autowired
    private TwitterConnectInterceptor twitterConnectInterceptor;

    @Inject
    private DataSource dataSource;

    @Inject
    private Environment environment;

    @Bean
    public UserIdSource userIdSource() {
        return new UserIdSource() {         
            @Override
            public String getUserId() {
                return "myTestingPurposesLogin"; // TODO change to security-obtained user login
            }
        };
    }

    @Bean
    public ConnectController connectController() {
        CustomConnectController connectionController = 
                new CustomConnectController(connectionFactoryLocator(), connectionRepository());
        connectionController.addInterceptor(twitterConnectInterceptor);
        return connectionController;
    }

    @Bean
    public ConnectionFactoryLocator connectionFactoryLocator() {
        ConnectionFactoryRegistry registry = new ConnectionFactoryRegistry();

        registry.addConnectionFactory(new TwitterConnectionFactory(
                "myAppId", "myAppSecret"));

        return registry;
    }

    @Bean
    @Scope(value="request", proxyMode=ScopedProxyMode.INTERFACES)
    public ConnectionRepository connectionRepository() {
        Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
        if (authentication == null) {
            throw new IllegalStateException("Unable to get a ConnectionRepository: no user signed in");
        }
        return usersConnectionRepository().createConnectionRepository(authentication.getName());
    }

    @Bean
    public UsersConnectionRepository usersConnectionRepository() {
        return new JdbcUsersConnectionRepository(dataSource, connectionFactoryLocator(), 
            textEncryptor());
    }

    @Bean
    public TextEncryptor textEncryptor() {
        return Encryptors.noOpText();
    }

}

Answer 1

Хорошо, я делал это совершенно неправильно! Вот простой в использовании рабочий пример:

@Configuration
@EnableTwitter(appId="myAppId", appSecret="myAppSecret")
@EnableJdbcConnectionRepository
public class TwitterConfig {

    @Autowired
    private TwitterConnectInterceptor twitterConnectInterceptor;

    @Bean
    public UserIdSource userIdSource() {
        return new UserIdSource() {         
            @Override
            public String getUserId() {
                return "myTestingPurposesLogin";
            }
        };
    }

    @Bean
    public ConnectController connectController(ConnectionFactoryLocator connectionFactoryLocator, ConnectionRepository connectionRepository) {
        CustomConnectController connectionController = new CustomConnectController(connectionFactoryLocator, connectionRepository);
        connectionController.addInterceptor(twitterConnectInterceptor);
            return connectionController;
    }

    @Bean
    public TextEncryptor textEncryptor() {
        return Encryptors.noOpText();
    }

}

@EnableJdbcConnectionRepository аннотация имела решающее значение, чтобы вывести меня на правильный путь.

Answer 2

+ Изменить

tweets.addAll(twitter.timelineOperations().getHomeTimeline());

Примерно так (псевдокод, я не знаю всех типов, которые возвращаются):

var timelineOperations = twitter.TimelineOperations();
var homeTimeline = timelineOperations.GetHomeTimeline();
tweets.addAll(homeTimeline);

Это скажет вам, какой вызов метода не возвращает объект.