我正在开发一个使用 Spring 3 和 Spring Security 的项目。我的问题是 IoC 容器。当我编写自己的 UserDetailsService 实现时，问题就开始了对于 Spring Security-3。我检查了其他问题，但仍然无法解决问题。

问题的定义是:

我有两个单独的类(一个是 UsersController.java 扩展 @Controller 和 ProjectUserDetailsService 扩展 @Service )使用一个通用对象进行 Autowiring 。但是当对象在 UsersController 中成功 Autowiring 时, 是 null在 ProjectUserDetailsService虽然这个类的对象(ProjectUserDetailsService)已经成功创建(我通过调试验证了这一点)。

有什么建议可以解决这个问题吗？

这是我的web.xml , project-servlet.xml和 project-security.xml文件和相关类。

Web.xml`

<?xml version="1.0" encoding="UTF-8"?>
<!--
  - Tutorial web application
  -
  -->
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
  <display-name>Ecognitio with Spring Security</display-name>
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>
            /WEB-INF/ecognitio-servlet.xml
            /WEB-INF/ecognitio-security.xml
        </param-value>
  </context-param>
  <context-param>
    <param-name>webAppRootKey</param-name>
    <param-value>tutorial.root</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>
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  <listener>
    <listener-class>org.springframework.security.web.session.HttpSessionEventPublisher</listener-class>
  </listener>
  <servlet>
    <servlet-name>ecognitio</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>project</servlet-name>
    <url-pattern>*.action</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>project</servlet-name>
    <url-pattern>*.html</url-pattern>
  </servlet-mapping>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

project-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="
    http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

    <!-- Scans the classpath of this application for @Components to deploy as beans -->
    <context:component-scan base-package="com.project" />

    <!-- Configures the @Controller programming model -->
    <mvc:annotation-driven />

     <bean  id="messageSource" 
            class="org.springframework.context.support.ResourceBundleMessageSource"
            p:basename="Messages"/>

  <!-- misc -->
<!--    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
        <property name="suffix" value=".jsp"/>
    </bean>  --> 


    <bean id="viewResolver"
        class="org.springframework.web.servlet.view.UrlBasedViewResolver">

       <property name="viewClass">
         <value>
              org.springframework.web.servlet.view.tiles2.TilesView
            </value>
        </property>
    </bean>

    <bean id="tilesConfigurer"
    class="org.springframework.web.servlet.view.tiles2.TilesConfigurer">
      <property name="definitions">
             <list>
                <value>/WEB-INF/tiles.xml</value>
             </list>
      </property>
    </bean>

    <!-- Configures Hibernate - Database Config -->
    <import resource="db-config.xml" />
</beans>

project-security.xml

<?xml version="1.0" encoding="UTF-8"?>

<!--
  - Sample namespace-based configuration
  -
  -->

<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-3.0.xsd
                        http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.1.xsd">

    <debug />

    <global-method-security pre-post-annotations="enabled">
        <!-- AspectJ pointcut expression that locates our "post" method and applies security that way
        <protect-pointcut expression="execution(* bigbank.*Service.post*(..))" access="ROLE_TELLER"/>
        -->
    </global-method-security>

    <http pattern="/loggedout.jsp" security="none"/>

    <http use-expressions="true" >
        <intercept-url pattern="/secure/extreme/**" access="hasRole('ROLE_SUPERVISOR')"/>
        <intercept-url pattern="/secure/**" access="isAuthenticated()" />

        <!--
             Allow all other requests. In a real application you should
             adopt a whitelisting approach where access is not allowed by default
          -->
        <intercept-url pattern="/login.jsp*" access="isAuthenticated()==false"/>
        <intercept-url pattern="/timeout.jsp*" access="isAuthenticated()==false"/>
        <intercept-url pattern="/**" access="hasRole('ROLE_USER')" />

       <!-- <intercept-url pattern="/**" access="permitAll" /> --> 
        <form-login login-page="/login.jsp" authentication-failure-url="/login.jsp?login_error=1" default-target-url="/dashboard.html" />
        <logout logout-success-url="/login.jsp" delete-cookies="JSESSIONID"/>
        <remember-me />
<!--
    Uncomment to enable X509 client authentication support
        <x509 />
-->
        <!-- Uncomment to limit the number of sessions a user can have 
        <session-management invalid-session-url="/login.jsp">
            <concurrency-control max-sessions="1" error-if-maximum-exceeded="true" />
        </session-management>
        -->

    </http>

            <!-- HERE IS WHERE I USE an object of ProjectUserDetailsService -->
    <authentication-manager>
         <authentication-provider user-service-ref="userDetailsService" />   
    </authentication-manager>


 <!--  

</beans:beans>

UsersController.java (该类的UsersDAO类对象 Autowiring 成功)

package com.project.users;

//required imports



@Controller
public class UsersControllers
{

@Autowired
private UsersDAO usersDAO;

    //Some more autowires and some class specific code


}

ProjectUserDetailsService.java (UsersDAO 的 Autowiring 不起作用)

package com.project.security;

import java.util.ArrayList;
import java.util.Collection;

//required imports


@SuppressWarnings("deprecation")
@Service("userDetailsService") 
public class ProjectUserDetailsService implements UserDetailsService {

   @Autowired
   private UsersDAO usersDAO;
  @Autowired private Assembler assembler;

  @Transactional(readOnly = true)
  public UserDetails loadUserByUsername(String username)
      throws UsernameNotFoundException, DataAccessException {

    UserDetails userDetails = null;
    //For debugging purposes
    if(usersDAO==null){
        System.out.println("DAO IS NULL");
        System.out.println("DAO IS NULL");
        System.out.println("DAO IS NULL");

    }
    User userEntity = usersDAO.findUserbyEmail("'"+username+"'");


    if (userEntity == null)
      throw new UsernameNotFoundException("user not found");

    return assembler.buildUserFromUserEntity(userEntity);

  }
}

最佳答案

是的，将对象 Autowiring 到从 Spring 安全类继承的 bean 中似乎是不可能的。我不知道这是否是 Spring Security 中的一个错误，或者它是为了安全还是什么。如果有人有解释，我很想听听。您可以通过 xml 配置手动注入(inject) bean(而不是使用 @Autowired 注释)来解决您的问题，然后它们就会出现。不过要注意一句..

我这样做了，我注意到我的带有注释的 userDao(特别是 @Transactional)不再在事务中运行。我的 userDao 正在多个地方使用。但是，如果我将它注入(inject)到我的自定义 AbstractUserDetailsAuthenticationProvider 中，它就不再在使用它的任何其他类的事务中运行。当其他正在接收它的对象(通过@Autowired 或手动 xml 注入(inject))使用时，删除对自定义 AbstractUserDetailsAuthenticationProvider 的注入(inject)将事务功能恢复到我的 userDao。

那么我是如何让我的 userDao 进入我的 Spring Security 上下文并仍然保留它@Transactional 的呢？我必须创建一个工厂类:

public class UserDaoFactory {

private static UserDao userDao;

public static UserDao getUserDao() {
    return UserDaoFactory.userDao;
}

public void setUserDao(UserDao userDao) {
    UserDaoFactory.userDao = userDao;
}
}

然后把这个和你的dao两个对象放入spring容器中:

<bean id="userDao" class="com.package.UserDaoImpl">
    <property name="sessionFactory" ref="sessionFactory" />
</bean>

<bean id="userDaoFactory" class="com.package.UserDaoFactory">
    <property name="userDao" ref="userDao" />
</bean>

因此 userDao 将 Autowiring 到您的 userDaoFactory 中。它将具有所有 @Transactional 功能(因为 spring security 没有将其剥离？)。然后在您的 spring 安全对象中，您可以执行以下操作:

userDao = UserDaoFactory.getUserDao();

我在我的自定义 AbstractUserDetailsAuthenticationProvider 对象中实现了 ServletContextAware 以在初始化期间执行上述操作一次，中提琴。

所以请注意，虽然您可以通过 xml 配置手动将 bean 注入(inject)到 spring 安全对象中以克服 @Autowired 问题，但如果您尝试将该 DAO 包装在 @Transactional 中，您最终会遇到一个新问题。

现在也许有人知道为什么会发生这种情况。这可能是我的错误配置(我承认我不是 Spring 专家)，或者它可能是 Spring 的一个特性。我很想听听任何人要说什么以及如何改进这一点。

关于spring - @Autowired 对象在一个类中获得空值，而在另一个类中成功连接，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/5921717/