Java 在tomcat启动时，自动连线：异常将上下文初始化事件发送到类的侦听器实例

我尝试使用find all从db获取所有更新，但出现此错误。我使用debug，并在ServletContextListener中看到DbUpdateService为null。我觉得autowired有些问题，只是我不明白。在控制器类中，它只在ServletContextListener中正常工作，而不是在ServletContextListener中。我尝试将@Controller或@Component或@service注释放在ServletContextListener类之前，但没有帮助我。有什么想法吗

ServletContextListener

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不确定要自动连接时是否应创建新对象

@Autowired
private IDbUpdatesService dbUpdatesService = new DbUpdatesService();

试一试

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我在我的问题上找到了一个很好的答案，首先是@Alan Barrows如何说我不需要

new DbUpdateService（）我用了这个

@Override
public void contextInitialized(ServletContextEvent sce) {
    WebApplicationContextUtils
        .getRequiredWebApplicationContext(sce.getServletContext())
        .getAutowireCapableBeanFactory()
        .autowireBean(this);

    //Do something with props
    ...
}    

@Override
    @Transactional("txManager")
    public List<T> findAll() {
        return getDao().findAll();
    }

@Service("iDbUpdatesService")
@Transactional(propagation = Propagation.SUPPORTS, readOnly = true)  
public class DbUpdatesService extends  AbstractService<DbUpdates, Long> implements IDbUpdatesService{

    @Autowired
    private IDbUpdatesDao DbUpdatesDao;

    public DbUpdatesService() {
        super();
    }

    public void setDbUpdatesDao(IDbUpdatesDao DbUpdatesDao) {
        this.DbUpdatesDao = DbUpdatesDao;
    }

    @Override
    protected IOperations<DbUpdates, Long> getDao() {
        return DbUpdatesDao;
    }

}

SEVERE: Exception sending context initialized event to listener instance of class com.atni.hrms.persistence.model.listeners.HRMSServletContextListener
java.lang.NullPointerException
    at com.awinta.hrms.persistence.service.common.AbstractService.findAll(AbstractService.java:24)
    at com.awinta.hrms.persistence.model.listeners.HRMSServletContextListener.checkNewUpdate(HRMSServletContextListener.java:69)
    at com.awinta.hrms.persistence.model.listeners.HRMSServletContextListener.contextInitialized(HRMSServletContextListener.java:47)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4791)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5285)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)

@Autowired
private IDbUpdatesService dbUpdatesService = new DbUpdatesService();

@Autowired
private IDbUpdatesService dbUpdatesService;

@Override
public void contextInitialized(ServletContextEvent sce) {
    WebApplicationContextUtils
        .getRequiredWebApplicationContext(sce.getServletContext())
        .getAutowireCapableBeanFactory()
        .autowireBean(this);

    //Do something with props
    ...
}