Error creating Spring bean

问题:

I'm using Spring 3.1.4

Controller class

package com.demo.scheduler.controller;

import java.util.Map;

import com.demo.scheduler.service.SchedulerService;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class SchedulerController {

    private SchedulerService service;

    @Autowired
    public SchedulerController(SchedulerService service) {
        this.service = service;

    }

    @RequestMapping(value = "/tasklist",method = RequestMethod.GET)
    public String listTask(Map<String, Object> model) {
        model.put("task", service.getTask());

        return "tasklist";

    }
}

Service Implementation

package com.demo.scheduler.service;

import com.demo.scheduler.TaskConfig;

@Service
@Transactional(propagation = Propagation.SUPPORTS, readOnly = true)
public class SchedulerServiceImpl implements SchedulerService {
    @Autowired
    public SchedulerDAO schedulerDAO;

    @Override
    @Transactional(propagation = Propagation.REQUIRED, readOnly = false)
    public List<TaskConfig> getTask() {

        return schedulerDAO.getTask();
    }

}

DAO Implementation

package com.demo.scheduler.dao;

import com.demo.scheduler.TaskConfig;

import java.util.List;

import org.hibernate.SessionFactory;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

@Repository
public class HibernateDAO implements SchedulerDAO {

    @Autowired
    private SessionFactory sessionFactory;

    public HibernateDAO(SessionFactory sessionFactory) {
        this.sessionFactory = sessionFactory;

    }

    @SuppressWarnings("unchecked")
    @Override
    public List<TaskConfig> getTask() {

        return sessionFactory.getCurrentSession().createCriteria(
                TaskConfig.class).list();
    }

}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.4"
    xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
    <display-name>demoscheduler</display-name>
    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>default.html</welcome-file>
        <welcome-file>default.htm</welcome-file>
        <welcome-file>default.jsp</welcome-file>
    </welcome-file-list>

    <servlet>
        <servlet-name>demo</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet
        </servlet-class></servlet>

    <servlet-mapping>
        <servlet-name>demo</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping><session-config>
        <session-timeout>60</session-timeout>
    </session-config>
</web-app>

demo-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:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx"
    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/tx 
           http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">

    <context:component-scan base-package="com.demo.scheduler" />
    <context:annotation-config />
    <tx:annotation-driven />

    <bean id="jspViewResolver"
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass"
            value="org.springframework.web.servlet.view.JstlView" />
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>

    <bean id="propertyConfigurer"
        class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location">
            <value>/WEB-INF/resources/hibernate.properties
            </value>
        </property>
    </bean>


    <bean class="org.springframework.orm.hibernate3.LocalSessionFactoryBean"
        id="sessionFactory">
        <property name="dataSource" ref="dataSource">
        </property>
        <property name="configLocations">
            <list>
                <value>/WEB-INF/resources/schedulerTask.hbm.xml
                </value>
            </list>
        </property>
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">${hibernate.dialect}</prop>
                <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
                <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
                <prop key="hibernate.connection.provider_class">${hibernate.connection.provider_class}
                </prop>
                <prop key="hibernate.c3p0.acquire_increment">${hibernate.c3p0.acquire_increment}
                </prop>
                <prop key="hibernate.c3p0.idle_test_period">${hibernate.c3p0.idle_test_period}
                </prop>
                <prop key="hibernate.c3p0.max_size">${hibernate.c3p0.max_size}
                </prop>
                <prop key="hibernate.c3p0.max_statements">${hibernate.c3p0.max_statements}
                </prop>
                <prop key="hibernate.c3p0.min_size">${hibernate.c3p0.min_size}
                </prop>
                <prop key="hibernate.c3p0.timeout">${hibernate.c3p0.timeout}
                </prop>
            </props>
        </property>
    </bean>

    <bean class="org.springframework.jdbc.datasource.DriverManagerDataSource"
        id="dataSource">

        <property name="driverClassName" value="${hibernate.connection.driver_class}" />
        <property name="url" value="${hibernate.connection.url}" />
        <property name="username" value="${hibernate.connection.username}" />
        <property name="password" value="${hibernate.connection.password}" />
    </bean>



    <bean id="transactionManager"
        class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>

</beans>

After updating the code, I getting the following error:

9544 [http-4186-2] ERROR org.springframework.web.servlet.DispatcherServlet - Context initialization failed org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'schedulerController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.demo.scheduler.service.SchedulerService com.demo.scheduler.controller.SchedulerController.service; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'schedulerServiceImpl': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: public com.demo.scheduler.dao.SchedulerDAO com.demo.scheduler.service.SchedulerServiceImpl.schedulerDAO; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hibernateDAO': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.hibernate.SessionFactory com.demo.scheduler.dao.HibernateDAO.sessionFactory; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:287) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1106) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:607) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:925) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:472) at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:631) at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:588) at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:645) at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:508) at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:449) at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:133) at javax.servlet.GenericServlet.init(GenericServlet.java:212) at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1161) at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:806) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:129) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:263) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:584) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447) at java.lang.Thread.run(Thread.java:662) Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.demo.scheduler.service.SchedulerService com.demo.scheduler.controller.SchedulerController.service; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'schedulerServiceImpl': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: public com.demo.scheduler.dao.SchedulerDAO com.demo.scheduler.service.SchedulerServiceImpl.schedulerDAO; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hibernateDAO': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.hibernate.SessionFactory com.demo.scheduler.dao.HibernateDAO.sessionFactory; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:513) at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:92) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:284) ... 29 more Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'schedulerServiceImpl': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: public com.demo.scheduler.dao.SchedulerDAO com.demo.scheduler.service.SchedulerServiceImpl.schedulerDAO; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hibernateDAO': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.hibernate.SessionFactory com.demo.scheduler.dao.HibernateDAO.sessionFactory; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:287) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1106) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:269) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193) at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:871) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:813) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:730) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:485) ... 31 more Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: public com.demo.scheduler.dao.SchedulerDAO com.demo.scheduler.service.SchedulerServiceImpl.schedulerDAO; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hibernateDAO': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.hibernate.SessionFactory com.demo.scheduler.dao.HibernateDAO.sessionFactory; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:513) at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:92) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:284) ... 44 more Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hibernateDAO': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.hibernate.SessionFactory com.demo.scheduler.dao.HibernateDAO.sessionFactory; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:287) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1106) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193) at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:871) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:813) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:730) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:485) ... 46 more Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.hibernate.SessionFactory com.demo.scheduler.dao.HibernateDAO.sessionFactory; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:513) at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:92) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:284) ... 57 more Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1455) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193) at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:871) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:813) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:730) at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:485)

回答1:

If found out my error.The problem is that there is nothing in that configuration to instantiate my DAO bean. So, I modified my "context:component-scan" element in application context to also pick up my DAO.

<context:component-scan base-package="com.demo.scheduler">
        <context:include-filter type="annotation"
            expression="org.springframework.stereotype.Service" />
        <context:include-filter type="annotation"
            expression="org.springframework.stereotype.Repository" />
        <context:exclude-filter type="annotation"
            expression="org.springframework.stereotype.Controller" />
    </context:component-scan>

Thanks for the help @M.Deinum and @SotiriosDelimanolis

回答2:

Try to add the ContextLoaderListener in your web.xml:

<listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>