关于 java:org.springframework.beans.factory.UnsatisfiedDependencyException: Error created bean with name //’bookDaoImpl//’

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name ‘bookDaoImpl’: Unsatisfied dependency expressed through field ‘sessionFactory’; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘getSessionFactory’ defined in com.example.spring.config.AppConfig: Invocation of init method failed;

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.example.spring</groupId>
  library–service</artifactId>
  <version>0.0.1–SNAPSHOT</version>
  <packaging>war</packaging>

  <properties>
    <project.build.sourceEncoding>UTF–8</project.build.sourceEncoding>
    <failOnMissingWebXml>false</failOnMissingWebXml>
    <hibernate.version>5.2.8.Final</hibernate.version>
  </properties>

  <dependencies>
    <!– Servlet API –>
    <dependency>
        <groupId>javax.servlet</groupId>
        javax.servlet–api</artifactId>
        <version>3.1.0</version>
        <scope>provided</scope>
    </dependency>
    <!– Spring MVC –>
    <dependency>
        <groupId>org.springframework</groupId>
        spring–webmvc</artifactId>
        <version>4.3.10.RELEASE</version>
    </dependency>
    <!– Spring ORM –>
    <dependency>
        <groupId>org.springframework</groupId>
        spring–orm</artifactId>
        <version>4.3.10.RELEASE</version>
    </dependency>
    <!– Hibernate ORM –>
    <dependency>
        <groupId>org.hibernate</groupId>
        hibernate–core</artifactId>
        <version>${hibernate.version}</version>
    </dependency>
    <!– Hibernate–c3p0 Integration –>
    <dependency>
        <groupId>org.hibernate</groupId>
        hibernate–c3p0</artifactId>
        <version>${hibernate.version}</version>
    </dependency>
    <!– c3p0 –>
    <dependency>
        <groupId>com.mchange</groupId>
        c3p0</artifactId>
        <version>0.9.5.2</version>
    </dependency>
    <!– MySQL Connector –>
    <dependency>
        <groupId>mysql</groupId>
        mysql–connector–java</artifactId>
        <version>6.0.5</version>
    </dependency>
    <!– Jackson API for JSON –>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        jackson–databind</artifactId>
        <version>2.8.7</version>
    </dependency>

  </dependencies>

  <build>
    <sourceDirectory>src/main/java</sourceDirectory>
    <plugins>
        <plugin>
            maven–compiler–plugin</artifactId>
            <version>3.5.1</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>

        <!– Embedded Apache Tomcat required for testing war –>
        <plugin>
            <groupId>org.apache.tomcat.maven</groupId>
            tomcat7–maven–plugin</artifactId>
            <version>2.2</version>
            <configuration>
                <path>/</path>
            </configuration>
        </plugin>
    </plugins>
  </build>
</project>

    package com.example.spring.model;

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

    @Entity(name ="Book")
    public class Book {

        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private Long id;
        private String title;
        private String author;

        public Book() {
        }

        public Long getId() {
            return id;
        }

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

        public String getTitle() {
            return title;
        }

        public void setTitle(String title) {
            this.title = title;
        }

        public String getAuthor() {
            return author;
        }

        public void setAuthor(String author) {
            this.author = author;
        }
    }

package com.example.spring.service;

    import java.util.List;

    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import org.springframework.transaction.annotation.Transactional;

    import com.example.spring.dao.BookDao;
    import com.example.spring.model.Book;

    @Service
    @Transactional(readOnly = true)
    public class BookServiceImpl implements BookService {

        @Autowired
        private BookDao bookDao;

        @Transactional
        public long save(Book book) {
            return bookDao.save(book);
        }

        public Book get(long id) {
            return bookDao.get(id);
        }

        @Transactional
        public void update(long id, Book book) {
            bookDao.update(id, book);

        }

        @Transactional
        public void delete(long id) {
            bookDao.delete(id);
        }

        public List<Book> list() {
            return bookDao.list();
        }

    }

package com.example.spring.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import com.example.spring.dao.BookDao;
import com.example.spring.model.Book;

@Service
@Transactional(readOnly = true)
public class BookServiceImpl implements BookService {

    @Autowired
    private BookDao bookDao;

    @Transactional
    public long save(Book book) {
        return bookDao.save(book);
    }

    public Book get(long id) {
        return bookDao.get(id);
    }

    @Transactional
    public void update(long id, Book book) {
        bookDao.update(id, book);

    }

    @Transactional
    public void delete(long id) {
        bookDao.delete(id);
    }

    public List<Book> list() {
        return bookDao.list();
    }

}

package com.example.spring.dao;

import java.util.List;

import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;

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

import com.example.spring.model.Book;

@Repository
public class BookDaoImpl implements BookDao {

    @Autowired
    private SessionFactory sessionFactory;

    public long save(Book book) {
        sessionFactory.getCurrentSession().save(book);
        return book.getId();
    }

    public Book get(long id) {
        return sessionFactory.getCurrentSession().get(Book.class, id);
    }

    public void update(long id, Book book1) {
        Session session = sessionFactory.getCurrentSession();
        Book book2 = session.byId(Book.class).load(id);
        book2.setTitle(book1.getTitle());
        book2.setAuthor(book1.getAuthor());
        session.flush();
    }

    public void delete(long id) {
        Session session = sessionFactory.getCurrentSession();
        Book book = session.byId(Book.class).load(id);
        session.delete(book);
    }

    public List<Book> list() {
        Session session = sessionFactory.getCurrentSession();
        CriteriaBuilder cb = session.getCriteriaBuilder();
        CriteriaQuery<Book> cq = cb.createQuery(Book.class);
        Root<Book> root = cq.from(Book.class);
        cq.select(root);
        Query<Book> query = session.createQuery(cq);
        return query.getResultList();
    }

}

package com.example.spring.config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@Configuration
@EnableWebMvc
@ComponentScan(basePackages = {"com.example.spring.controller" })
public class WebConfig extends WebMvcConfigurerAdapter {

}

package com.example.spring.config;

import java.util.Properties;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.ComponentScans;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.orm.hibernate5.HibernateTransactionManager;
import org.springframework.orm.hibernate5.LocalSessionFactoryBean;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import static org.hibernate.cfg.Environment.*;

@Configuration
@PropertySource("classpath:db.properties")
@EnableTransactionManagement
@ComponentScans(value = { @ComponentScan("com.example.spring.dao"),
        @ComponentScan("com.example.spring.service")})
public class AppConfig {

    @Autowired
    private Environment env;

    @Bean
    public LocalSessionFactoryBean getSessionFactory() {
        LocalSessionFactoryBean factoryBean = new LocalSessionFactoryBean();

        Properties props = new Properties();
        // Setting JDBC properties
        props.put(DRIVER, env.getProperty("mysql.driver"));
        props.put(URL, env.getProperty("mysql.url"));
        props.put(USER, env.getProperty("mysql.user"));
        props.put(PASS, env.getProperty("mysql.password"));

        // Setting Hibernate properties
        props.put(SHOW_SQL, env.getProperty("hibernate.show_sql"));
        props.put(HBM2DDL_AUTO, env.getProperty("hibernate.hbm2ddl.auto"));

        // Setting C3P0 properties
        props.put(C3P0_MIN_SIZE, env.getProperty("hibernate.c3p0.min_size"));
        props.put(C3P0_MAX_SIZE, env.getProperty("hibernate.c3p0.max_size"));
        props.put(C3P0_ACQUIRE_INCREMENT, env.getProperty("hibernate.c3p0.acquire_increment"));
        props.put(C3P0_TIMEOUT, env.getProperty("hibernate.c3p0.timeout"));
        props.put(C3P0_MAX_STATEMENTS, env.getProperty("hibernate.c3p0.max_statements"));

        factoryBean.setHibernateProperties(props);
        factoryBean.setPackagesToScan("com.example.spring.model");

        return factoryBean;
    }

    @Bean
    public HibernateTransactionManager getTransactionManager() {
        HibernateTransactionManager transactionManager = new HibernateTransactionManager();
        transactionManager.setSessionFactory(getSessionFactory().getObject());
        return transactionManager;
    }
}

package com.example.spring.config;

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

public class MyWebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    protected Class< ? >[] getRootConfigClasses() {
        return new Class[] { AppConfig.class };
    }

    @Override
    protected Class< ? >[] getServletConfigClasses() {
        return new Class[] { WebConfig.class };
    }

    @Override
    protected String[] getServletMappings() {
        return new String[] {"/" };
    }

}

# MySQL properties
mysql.driver=com.mysql.cj.jdbc.Driver
mysql.url=jdbc:mysql://localhost:3306/library
mysql.user=root
mysql.password=****

# Hibernate properties
hibernate.show_sql=true
hibernate.hbm2ddl.auto=update

#C3P0 properties
hibernate.c3p0.min_size=5
hibernate.c3p0.max_size=20
hibernate.c3p0.acquire_increment=1
hibernate.c3p0.timeout=1800
hibernate.c3p0.max_statements=150

<dependency>
    <groupId>mysql</groupId>
    mysql–connector–java</artifactId>
    <version>8.0.16</version>
</dependency>