Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/spring-mvc-crud-demo-servlet.xml]:

Question

Why am I getting error as below:

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/spring-mvc-crud-demo-servlet.xml]: Invocation of init method failed; nested exception is org.hibernate.AnnotationException: No identifier specified for entity: springmvc.miniproject.entity.Review

import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToMany;
import javax.persistence.Table;

@Entity
@Table(name="reviews")
public class Review {
    
    private int id;
    private String reviews;
    @ManyToMany(fetch=FetchType.LAZY,cascade= {CascadeType.DETACH,CascadeType.MERGE,CascadeType.PERSIST,CascadeType.REFRESH})
    @JoinColumn(name="id")
    private Course course;
    
    public Review() {}
    public Review(int id, String reviews) {
    //  super();
        this.id = id;
        this.reviews = reviews;
    }

    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getReviews() {
        return reviews;
    }
    
    public void setReviews(String reviews) {
        this.reviews = reviews;
    }
    public Course getCourse() {
        return course;
    }
    public void setCourse(Course course) {
        this.course = course;
    }
    
}

package springmvc.miniproject.entity;

import java.util.List;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToMany;
import javax.persistence.Table;

@Entity
@Table(name="courses")
public class Course {
    
    @Id
    @Column(name="id")
    private int id;
    @Column(name="Course_name")
    private String courseName;
    
    @OneToMany(fetch=FetchType.LAZY,cascade=CascadeType.ALL)
    @JoinColumn(name="course_id")
    private List<Review> review;
    
    public Course() {}
    public Course(int id, String courseName) {
        this.id = id;
        this.courseName = courseName;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getCourseName() {
        return courseName;
    }
    public void setCourseName(String courseName) {
        this.courseName = courseName;
    }
    public List<Review> getReview() {
        return review;
    }
    public void setReview(List<Review> review) {
        this.review = review;
    }
    
}


package springmvc.miniproject.DAO;

import java.util.List;

import springmvc.miniproject.entity.Course;

public interface CourseDAO {
    
    public List<Course> getAllCourses();

}


package springmvc.miniproject.DAO;

import java.util.ArrayList;
import java.util.List;

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

import springmvc.miniproject.entity.Course;
import springmvc.miniproject.entity.InstructorPersonalInfo;
import springmvc.miniproject.entity.Review;
import springmvc.miniproject.DAO.Instructor;
import springmvc.miniproject.controller.InstructorDetails;

@Repository
public class CourseDAOImpl implements CourseDAO,ReviewDAO {
    
    @Autowired
    private SessionFactory factory;
    
    @Override
    @Transactional
    public List<Course> getAllCourses() {
        System.out.println("getAllCourses");
        //get current session
        Session session = factory.getCurrentSession();
        //create query
        Query<Course> query = session.createQuery("from Course", Course.class);
        //execute query
        List<Course> course = query.getResultList();
        if (course == null) {
            System.out.println("null returned from query");
        } else {System.out.println(course);}
        return course;
    }

    @Override
    public List<Review> getReviewForACourse(int courseId) {
        // TODO Auto-generated method stub
        return null;
    }

}

-----------------------

<?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="springmvc.miniproject" />

    <!-- 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.cj.jdbc.Driver" />
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/hb_tution_tracker?useSSL=false&amp;serverTimezone=UTC" />
        <property name="user" value="hbstudent" />
        <property name="password" value="hbstudent" /> 

        <!-- these are connection pool properties for C3P0 -->
        <property name="initialPoolSize" value="5"/>
        <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="springmvc.miniproject.entity" />
        <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" />

    <!-- Add support for reading web resources: css, images, js, etc ... -->
    <mvc:resources location="/resources/" mapping="/resources/**"></mvc:resources>

</beans>```

Answer 1

org.hibernate.AnnotationException: No identifier specified for entity: springmvc.miniproject.entity.Review

Looks like you are missing @Id annotation on Review entity