Question

你好每个人都在做spring mvc和hibernate项目

我一直得到这个例外，我有controller class和DAO interface和DAO Implementation我配置了所有内容，但无法追查我的错误请看一下

HTTP Status 500 - Servlet.init() for servlet spring threw exception
 javax.servlet.ServletException: Servlet.init() for servlet spring threw exception
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
    org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1100)
    org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:687)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
    java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    java.lang.Thread.run(Unknown Source)


root cause
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'customerController': Unsatisfied dependency expressed through field 'customerDAO': No qualifying bean of type [com.loveTodo.springPractice.dao.inter.CustomerDAO] found for dependency [com.loveTodo.springPractice.dao.inter.CustomerDAO]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.loveTodo.springPractice.dao.inter.CustomerDAO] found for dependency [com.loveTodo.springPractice.dao.inter.CustomerDAO]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:569)
    org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
    org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:349)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
    org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:776)
    org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:861)
    org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:541)
    org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:668)
    org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:634)
    org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:682)
    org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:553)
    org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:494)
    org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
    javax.servlet.GenericServlet.init(GenericServlet.java:158)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
    org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1100)
    org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:687)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
    java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    java.lang.Thread.run(Unknown Source)


root cause
org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.loveTodo.springPractice.dao.inter.CustomerDAO] found for dependency [com.loveTodo.springPractice.dao.inter.CustomerDAO]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1406)
    org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1057)
    org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1019)
    org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:566)
    org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
    org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:349)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543)
    org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
    org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:776)
    org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:861)
    org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:541)
    org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:668)
    org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:634)
    org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:682)
    org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:553)
    org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:494)
    org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
    javax.servlet.GenericServlet.init(GenericServlet.java:158)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
    org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1100)
    org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:687)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
    java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    java.lang.Thread.run(Unknown Source

这是我的控制器类

package com.loveTodo.springPractice.controller;


import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.ModelAndView;

import com.loveTodo.springPractice.dao.inter.CustomerDAO;
import com.loveTodo.springPractice.entity.Customer;

@RestController  
@RequestMapping("/customer")
public class CustomerController   
{

    //need to inject the customer dao
    @Autowired
    private CustomerDAO customerDAO;

    @RequestMapping("/list")
    ModelAndView listCostomers(Model theModel)
    {
          //get the customers from the dao

        List<Customer> theCustomers=customerDAO.getCustomers();
        theModel.addAttribute("Customers",theCustomers);
        //add the customer to the modal
        return new ModelAndView("list-customers");

    }
}

这是我的DAO

    ackage com.loveTodo.springPractice.dao.inter;

import java.util.List;

import org.springframework.stereotype.Service;

import com.loveTodo.springPractice.entity.Customer;

public interface CustomerDAO {
    public List<Customer> getCustomers();
}

这是我的DAO实现类

package com.loveTodo.springPractice.dao.imp;

import java.util.List;

import javax.transaction.Transactional;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.query.Query;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import com.loveTodo.springPractice.dao.inter.CustomerDAO;
import com.loveTodo.springPractice.entity.Customer;

@Repository
public class CustomerDAOImpl implements CustomerDAO {

    @Autowired
    private SessionFactory sessionFactory;
    @Override
    @Transactional
    public List<Customer> getCustomers() 
    {
        //get the current hibernate session
        Session currentSession=sessionFactory.getCurrentSession();

        //create a query
        Query<Customer> theQuery=currentSession.createQuery("from Customer",Customer.class);

        //execute query and get the result list
        List<Customer> customers=theQuery.getResultList();

        //return the result

        return customers;
    }

}

请查看我的spring配置文件spring-servelt.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"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="
        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/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/tx 
        http://www.springframework.org/schema/tx/spring-tx.xsd">    

    <!-- Add support for component scanning -->  
    <context:component-scan base-package="com.loveTodo.springPractice.controller" />

    <!-- Add support for conversion, formatting and validation support -->
    <mvc:annotation-driven/>

    <!-- Define Spring MVC view resolver -->
    <bean
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/view/" />
        <property name="suffix" value=".jsp" />     
    </bean>

    <!-- Step 1: Define Database DataSource / connection pool -->
    <bean id="myDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
          destroy-method="close">
        <property name="driverClass" value="com.mysql.jdbc.Driver" />
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/hb_student_tracker?useSSL=false" />
        <property name="user" value="root" />
        <property name="password" value="root" /> 

        <!-- these are connection pool properties for C3P0 -->
        <property name="minPoolSize" value="5" />
        <property name="maxPoolSize" value="20" />
        <property name="maxIdleTime" value="30000" />
    </bean>  

    <!-- Step 2: Setup Hibernate session factory --> 
    <bean id="sessionFactory"
        class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
        <property name="dataSource" ref="myDataSource" />
        <property name="packagesToScan" value="com.loveTodo.springPractice.data" />  
        <property name="hibernateProperties">  
           <props>
              <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
              <prop key="hibernate.show_sql">true</prop>
           </props>
        </property>
   </bean>    

    <!-- Step 3: Setup Hibernate transaction manager -->
    <bean id="myTransactionManager"
            class="org.springframework.orm.hibernate5.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory"/>
    </bean>

    <!-- Step 4: Enable configuration of transactional behavior based on annotations -->
    <tx:annotation-driven transaction-manager="myTransactionManager" />

</beans>

请查看我的entity class

package com.loveTodo.springPractice.entity;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="customer")
public class Customer
{
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name="id")
    private int id;
    @Column(name="first_name")
    private String firstName;
    @Column(name="last_name")
    private String lastName;
    @Column(name="email")
    private String email;

    public Customer() {}

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    @Override
    public String toString() {
        return "Customer [id=" + id + ", firstName=" + firstName + ", lastName=" + lastName + ", email=" + email + "]";
    }


}

当我跑步时我一直得到这个例外，我无法追查我出错的地方请帮帮我

Answer 1

基于xml上下文配置文件，包含应由spring扫描的DAO实现的包不包含在component-scan标记中。正如您所看到的，它只是包含您的控制器的包，因此更改此行：

<context:component-scan base-package="com.loveTodo.springPractice.controller" />

这可以解决问题：

<context:component-scan base-package="com.loveTodo.springPractice" />

Answer 2

Spring没有检测到CustomerDaoImpl，因为它未定义xml配置且未包含在类路径扫描中

    <context:component-scan base-package="com.loveTodo.springPractice.controller" />

base-package控制搜索发生的位置，在你的情况下，只有om.loveTodo.springPractice.controller中的类或它的子包被spring扫描。

您可以通过在上下文中包含包含DAO的包来解决此问题：组件扫描，您可以指定多个包，如下所示：

<context:component-scan base-package="com.loveTodo.springPractice.controller, com.loveTodo.springPractice.dao.imp"/>

当然，例外本身就是非常自我解释的：

UnsatisfiedDependencyException: Error creating bean with name 'customerController': Unsatisfied dependency expressed through field 'customerDAO': No qualifying bean of type [com.loveTodo.springPractice.dao.inter.CustomerDAO]

它说spring不能创建customerController，因为它有一个依赖，spring不能在现场customerDAO中提供哪种类型的CustomerDAO

org.springframework.beans.factory.UnsatisfiedDependencyException：使用名称创建bean时出错（控制器）

2 个答案: