Spring Autowired 空指针异常

Question

I'm having some problems developing a very simple web application using Spring-MVC (4.2.5), Spring-Security (4.0.3) and MongoDB.

I'm trying to implement a custom authentication provider, in order to login the user via database, using DAO pattern. Although it seems to have initialized properly the application context, I'm having Null Pointer Exception on the Autowired variables (CustomerDao and CustomUserDetailsService).

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
    id="WebApp_ID" version="3.1">
    <display-name>AcmeSpring</display-name>
    <servlet>
        <servlet-name>SpringController</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>/WEB-INF/spring-mvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>SpringController</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            /WEB-INF/spring-security.xml
        </param-value>
    </context-param>
    <filter>
        <filter-name>springSecurityFilterChain</filter-name>
        <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>springSecurityFilterChain</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

spring-mvc.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mongo="http://www.springframework.org/schema/data/mongo"
    xsi:schemaLocation="http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/data/mongo 
        http://www.springframework.org/schema/data/mongo/spring-mongo-1.5.xsd">

    <mvc:annotation-driven />
    <context:component-scan base-package="controller" />
    <context:component-scan base-package="model" />
    <context:component-scan base-package="dao" />
    <context:component-scan base-package="service" />

    <mvc:resources mapping="/resources/**" location="/resources/" />

    <bean id="templateResolver"
        class="org.thymeleaf.templateresolver.ServletContextTemplateResolver">
        <property name="prefix" value="/WEB-INF/html/" />
        <property name="suffix" value=".html" />
        <property name="templateMode" value="HTML5" />
    </bean>

    <bean id="templateEngine" class="org.thymeleaf.spring4.SpringTemplateEngine">
        <property name="templateResolver" ref="templateResolver" />
    </bean>

    <bean class="org.thymeleaf.spring4.view.ThymeleafViewResolver">
        <property name="templateEngine" ref="templateEngine" />
        <property name="order" value="1" />
    </bean>

    <mongo:db-factory id="mongoDbFactory" host="localhost"
        port="27017" dbname="AcmeSpring" />

    <bean id="mongoTemplate" class="org.springframework.data.mongodb.core.MongoTemplate">
        <constructor-arg ref="mongoDbFactory" />
    </bean>

    <bean id="customerDao" class="dao.CustomerDaoImpl">
    </bean>
</beans>

spring-security.xml

<beans:beans xmlns="http://www.springframework.org/schema/security"
    xmlns:beans="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
    http://www.springframework.org/schema/security
    http://www.springframework.org/schema/security/spring-security-4.0.xsd">

    <http pattern="/resources/**" security="none" />

    <http auto-config="true">
        <intercept-url pattern="/user/**" access="hasRole('USER')" />
        <form-login authentication-failure-url="/login" login-page="/login"
            login-processing-url="/login" default-target-url="/user" />
        <logout invalidate-session="true" success-handler-ref="logoutSuccessHandler" />
    </http>

    <authentication-manager>
        <authentication-provider ref="customAuthenticationProvider" />
    </authentication-manager>

    <beans:bean id="customUserDetailsService" class="service.CustomUserDetailsService">
    </beans:bean>

    <beans:bean id="customAuthenticationProvider" class="service.CustomAuthenticationProvider">
    </beans:bean>

    <beans:bean id="logoutSuccessHandler" class="service.CustomLogoutSuccessHandler">
    </beans:bean>
</beans:beans>

CustomAuthenticationProvider

@Component
public class CustomAuthenticationProvider implements AuthenticationProvider {
    @Autowired
    CustomUserDetailsService userDetails;

    @Override
    public Authentication authenticate(Authentication authentication) throws AuthenticationException {
        String username = authentication.getName();
        String password = authentication.getCredentials().toString();

        System.out.println(userDetails == null);

        Customer customer = userDetails.loadUserByUsername(username);

        if(customer == null) {
            throw new BadCredentialsException("Username errato");
        }

        if(!password.equals(customer.getPassword())) {
            throw new BadCredentialsException("Password errata");
        }

        List<GrantedAuthority> authorities = new ArrayList<>();
        authorities.add(new SimpleGrantedAuthority(customer.getRole()));

        return new UsernamePasswordAuthenticationToken(customer, password, authorities);
    }

    @Override
    public boolean supports(Class<?> clazz) {
        return clazz.equals(UsernamePasswordAuthenticationToken.class);
    }
}

CustomUserDetailsService

@Service
public class CustomUserDetailsService implements UserDetailsService {
    @Autowired
    private CustomerDao customerDao;

    @Override
    public Customer loadUserByUsername(String username) throws UsernameNotFoundException {
        return customerDao.findCustomerByUsername(username);
    }
}

CustomerDaoImpl

@Repository
public class CustomerDaoImpl implements CustomerDao {
    private static final String COLLECTION = "Customer";
    @Autowired
    private MongoTemplate mongoTemplate;

    @Override
    public void create(Customer customer) {
        this.mongoTemplate.insert(customer, COLLECTION);
    }

    @Override
    public Customer findCustomerByUsername(String username) {
        Query query = new Query();
        query.addCriteria(Criteria.where("username").is(username));
        System.out.println(query.toString());
        return this.mongoTemplate.findOne(query, Customer.class);
    }
}

stack trace

java.lang.NullPointerException
    service.CustomUserDetailsService.loadUserByUsername(CustomUserDetailsService.java:18)
    service.CustomAuthenticationProvider.authenticate(CustomAuthenticationProvider.java:32)
    org.springframework.security.authentication.ProviderManager.authenticate(ProviderManager.java:167)
    org.springframework.security.authentication.ProviderManager.authenticate(ProviderManager.java:192)
    org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter.attemptAuthentication(UsernamePasswordAuthenticationFilter.java:93)
    org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:217)
    org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:120)
    org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    org.springframework.security.web.csrf.CsrfFilter.doFilterInternal(CsrfFilter.java:120)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:64)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:53)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:91)
    org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:213)
    org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:176)
    org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)
    org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262)

Where am I wrong? Thank you in advance.

EDIT: I don't have initialized the autowired variable manually, just bad paste, I've edited my code.

EDIT2: as suggested by @iMysak I remove the customerDao bean declaration from spring-mvc.xml and the 3 services bean declaration from spring-security.xml

new stack trace

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.security.filterChains': Cannot resolve reference to bean 'org.springframework.security.web.DefaultSecurityFilterChain#1' while setting bean property 'sourceList' with key [1]; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.security.web.DefaultSecurityFilterChain#1': Cannot create inner bean '(inner bean)#5adbfd3' of type [org.springframework.security.web.authentication.logout.LogoutFilter] while setting constructor argument with key [4]; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#5adbfd3': Cannot resolve reference to bean 'logoutSuccessHandler' while setting constructor argument; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'logoutSuccessHandler' is defined
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:359)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:108)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveManagedList(BeanDefinitionValueResolver.java:382)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:157)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1481)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1226)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:753)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:444)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:326)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4853)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5314)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1408)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1398)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.security.web.DefaultSecurityFilterChain#1': Cannot create inner bean '(inner bean)#5adbfd3' of type [org.springframework.security.web.authentication.logout.LogoutFilter] while setting constructor argument with key [4]; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#5adbfd3': Cannot resolve reference to bean 'logoutSuccessHandler' while setting constructor argument; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'logoutSuccessHandler' is defined
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:313)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:129)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveManagedList(BeanDefinitionValueResolver.java:382)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:157)
    at org.springframework.beans.factory.support.ConstructorResolver.resolveConstructorArguments(ConstructorResolver.java:634)
    at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:140)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1143)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1046)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:351)
    ... 26 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#5adbfd3': Cannot resolve reference to bean 'logoutSuccessHandler' while setting constructor argument; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'logoutSuccessHandler' is defined
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:359)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:108)
    at org.springframework.beans.factory.support.ConstructorResolver.resolveConstructorArguments(ConstructorResolver.java:634)
    at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:140)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1143)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1046)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveInnerBean(BeanDefinitionValueResolver.java:299)
    ... 40 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'logoutSuccessHandler' is defined
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:698)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1175)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:284)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:351)
    ... 48 more

I also tried adding aop, tx and expressions dependencies as suggested here but I get the above stack trace

Answer 1

It could be problem with using multiple context:component-scan tags. Please try next:

<context:component-scan base-package="controller model dao service" />

instead of declaration them separately.

Answer 2

You made the classic Spring bean mistake. You annotated the bean:

@Autowired
CustomUserDetailsService userDetails;

You called new:

userDetails = new CustomUserDetailsService();

It's either under Spring control or yours. The moment you called new, it was out of Spring's hands.

If you want Spring to auto wire dependencies, you cannot call new to initialize the reference. Let Spring do it.

Answer 3

Can you try getting rid of

<beans:bean id="customAuthenticationProvider" class="service.CustomAuthenticationProvider">
</beans:bean>

and

<beans:bean id="customUserDetailsService" class="service.CustomUserDetailsService">
    </beans:bean>

I think the XML declaration might be redundant with the annotation declaration and component scan