java - 将 Spring bean 注入(inject)到使用 new() 创建的外部类中

Question

我正在尝试在类中使用 spring bean。我正在从另一个 spring bean 访问这个类。我尝试使用 AutoWireCapableBeanFacory 以及 @Configurable + AspectJ LTW，但一次又一次地收到 java.lang.UnsupportedOperationException 。

我的场景如下:

ServiceOneImpl 调用 MyClass，并且 MyClass 使用另一个名为 MyService 的 bean( Autowiring )

//-------------------ServiceOne--------------
@Service("serviceOne")
public class ServiceOneImpl implements ServiceOne {
   @Override
   public void myMethod() {
       ClassA obj = new ClassA(arg1,arg2);
       obj.doSometing();

   } 
}

//-------------------MyService-------------
@Service("myService")
public class MyServiceImpl implements MyService {
   @Override
   public MyDTO getConfiguration(String arg) {
      return myDao.getConfiguration(arg);
   }
}

//-------------------MyClass--------------
@Component
public Class MyClass {

   @Autowired
   private MyService myService;

   private MyDTO myDTO;

   private String mailhost;
   private String arg1;
   private String arg2;

   public A() {
   }

   public A(String param1, String param2) {
       ServletContext context = (ServletContext) FacesContext.getCurrentInstance().getExternalContext().getContext();
       ApplicationContext applicationContext = WebApplicationContextUtils.getWebApplicationContext(context);   

       applicationContext.getAutowireCapableBeanFactory().
       autowireBeanProperties(this, AutowireCapableBeanFactory.AUTOWIRE_AUTODETECT,
       true);
       myDTO = myService.getConfiguration(); 
       mailhost = myDTO.getMailhost();

      //Do some process
   }
   public doSometing() {
      //Do some process
   }       
}

但我收到 java.lang.UnsupportedOperationException MyService 未 Autowiring ，它返回 null 值

javax.faces.el.EvaluationException: java.lang.UnsupportedOperationException
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:102)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
at javax.faces.component.UICommand.broadcast(UICommand.java:315)
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794)
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259)
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:329)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248)
at com.beo.atlas.common.filter.ClientSideCacheClearingFilter.doFilter(ClientSideCacheClearingFilter.java:34)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:280)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:248)
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$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:113)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:154)
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.www.BasicAuthenticationFilter.doFilter(BasicAuthenticationFilter.java:150)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:199)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:110)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:50)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersisten

我正在使用SpringFramework 4.0.3.RELEASE

我无法解决此问题。如果有人为我提供一些启发，这对我来说将是巨大的帮助

提前致谢

iMmo

Answer 1

除非您有充分的理由这样做，否则当您希望 Spring 将 bean 连接到对象时，请勿使用 new。并避免将域类绑定(bind)到 Spring。

恕我直言，您最好使用自定义构建器 bean:

public class ABuilder {
   @Autowired
   private MyService myService;

   public A getA(String param1, String param2) {
       A a = new A(param1, param2);
       a.setMyDTO(myService.getConfiguration()); 
       a.setMailhost(myDTO.getMailhost());
       return a;
   }
}

并相应地修改ServiceOne:

//-------------------ServiceOne--------------
@Autowired
ABuilder aBuilder;

@Service("serviceOne")
public class ServiceOneImpl implements ServiceOne {
   @Override
   public void myMethod() {
       ClassA obj = aBuilder.getA(arg1, arg2);
       obj.doSometing();
   } 
}

这样，A(或MyClass或ClassA)就可以没有对Spring的显式依赖，并且将通过其其他bean注入(inject) build 者。

当然，这不是真正的代码(参数和命名不连贯)，但你的也不是......