在 spring security dofilter 身份验证方法中使用 @Autowired 注释时出现空指针异常

Question

我用 @Service 注释了服务 class，如下所示：

@Service
public class SimpleApplicationSettingManager implements ApplicationSettingManager {
  
    @Autowired
    ApplicationSettingsDao applicationSettingsDao;

    //Method to Fetch value from the database
    @Override
    public boolean isConfigValue() {
         return applicationSettingsDao.getSettingsByKey(Constants.CONFIG_VALUE)
                .getValue().equalsIgnoreCase("true")?true:false;
    }
}

DAO class

public interface ApplicationSettingsDao extends GenericDao<ApplicationSettings, Long> {

    /**
     * @param key of the setting to retrive value
     * @return the value mapped against the key.
     */
    @Transactional
    ApplicationSettings getSettingsByKey(String key);
}

下面我正在尝试在 Spring 安全性中自动装配以保持进入会话

public class AuthenticationProcessingFilter extends AbstractAuthenticationProcessingFilter {
   
    private static final Log LOG = LogFactory.getLog(AuthenticationProcessingFilter.class);

    @Autowired
    private ApplicationSettingManager applicationSettingManager;

    public AuthenticationProcessingFilter(String filterProcessesUrl){
      super(filterProcessesUrl);
    }

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {

      if (req instanceof HttpServletRequest) {
        HttpServletRequest httpRequest = (HttpServletRequest) req;
        HttpSession httpSession = httpRequest.getSession();
        isCIAMEnabled= **applicationSettingManager**.isConfigValue();
        httpSession.setAttribute(Constants.SESSION_ATTR_CIAM_ENABLED, isCIAMEnabled);
      }
      super.doFilter(req, res, chain);
    }
}

结果如下所示 NullPointerException：

java.lang.NullPointerException
at service.SimpleApplicationSettingManager.isConfigValue(SimpleApplicationSettingManager.java:20)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:302)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor.proceedWithInvocation(TransactionInterceptor.java:99)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:208)
at com.sun.proxy.$Proxy124.isConfigValue(Unknown Source)
at web.filter.security.ciam.AuthenticationProcessingFilter.doFilter(AuthenticationProcessingFilter.java:85)

Answer 1

在我看来，这可能有两个原因：

getSettingsByKey(Constants.CONFIG_VALUE) returns null;
getSettingsByKey(Constants.CONFIG_VALUE) 事实上 returns 一个有效的非空值 ApplicationSettings 但是 getValue() 方法调用了它 returns null.

在 spring security dofilter 身份验证方法中使用 @Autowired 注释时出现空指针异常

Nullpointer Exception for @Autowired annotation while using that in spring security dofilter method of authentication

java

spring

hibernate

spring-security