Question

我有一个AuthenticationSuccessHandler，它应该持有UserService。我的问题是我在这行的userService上得到一个NullPointerException：

logger.debug(userService.getAllUsers().toString());

AuthenticationSuccessHandlerImpl：

@Repository
public class AuthenticationSuccessHandlerImpl implements AuthenticationSuccessHandler {
    private static final Logger logger = LoggerFactory.getLogger(AuthenticationSuccessHandlerImpl.class);

    @Autowired
    private UserService userService;

    @Override
    public void onAuthenticationSuccess(HttpServletRequest request, HttpServletResponse response, Authentication authentication) throws IOException, ServletException {         
        logger.debug(userService.getAllUsers().toString());

        response.setStatus(HttpServletResponse.SC_OK);  
        response.sendRedirect("index"); 
    }
}

我也尝试了@Service和@Component Annotation但是同样的错误。

它适用于我项目中的所有其他服务和控制器，但不适用于此Handler。

我的配置中也有这行代码：

<context:component-scan base-package="com.net4you.*" />

<tx:annotation-driven />

编辑： AuthenticationSuccessHandlerImpl不是使用new创建的，而是使用：

   <security:form-login login-page="/login" default-target-url="/index" authentication-failure-url="/fail2login" 
authentication-success-handler-ref="customAuthenticationSuccessHandler"/>

<beans:bean id="customAuthenticationSuccessHandler" class="com.net4you.slamanagement.helper.AuthenticationSuccessHandlerImpl"/>

项目结构：

调试器：

Answer 1

1）你不需要。*

<context:component-scan base-package="com.net4you.*" />

这就够了

<context:component-scan base-package="com.net4you" />

2）你确定userService是空的吗？

3）配置看起来很好，也许getAllUsers（）方法返回null，你能展示它的实现吗？

<强>更新

您可以通过两种方式解决此问题

1）删除

<beans:bean id="customAuthenticationSuccessHandler" class="com.net4you.slamanagement.helper.AuthenticationSuccessHandlerImpl"/>

并注释AuthenticationSuccessHandlerImpl，如下所示

@Component("customAuthenticationSuccessHandler")
public class AuthenticationSuccessHandlerImpl implements AuthenticationSuccessHandler {
    private static final Logger logger = LoggerFactory.getLogger(AuthenticationSuccessHandlerImpl.class);

    @Autowired
    private UserService userService;

    @Override
    public void onAuthenticationSuccess(HttpServletRequest request, HttpServletResponse response, Authentication authentication) throws IOException, ServletException {         
        logger.debug(userService.getAllUsers().toString());

        response.setStatus(HttpServletResponse.SC_OK);  
        response.sendRedirect("index"); 
    }
}

2）第二种方法是在AuthenticationSuccessHandlerImpl中创建用户服务的setter，手动在xml中创建userservice bean，然后使用xml中的authenticationSuccessHandlerImpl的setter属性直接注入它，这个解决方案比较复杂，我建议你先用一个

您的实现不起作用，因为您在xml中定义了bean而没有为其设置用户服务（如果您手动定义bean，则@autowired不起作用）然后您将此bean注入到form-login

Spring AuthenticationSuccessHandler自动装配服务/ DAO为空

1 个答案: