I am a beginner to spring. So right now I am starting to learn spring boot and build this simple project, but when I ran it I got this error " Field entityManager in sagala.rest.boot.remade.dao.EmployeeDaoImpl required a bean of type 'javax.persistence.EntityManager' that could not be found.".
Here is my controller class
package sagala.rest.boot.remade.controller;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import sagala.rest.boot.remade.entity.Employee;
import sagala.rest.boot.remade.service.EmployeeService;
@RestController
@RequestMapping("/api")
public class MainController {
@Autowired
private EmployeeService employeeService;
@GetMapping("/employees")
public List<Employee> findAll() {
    return employeeService.findAll();
}
}
Here is the Service class
package sagala.rest.boot.remade.service;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import sagala.rest.boot.remade.dao.EmployeeDao;
import sagala.rest.boot.remade.entity.Employee;
@Service
public class EmployeeServiceImpl implements EmployeeService {
@Autowired
private EmployeeDao employeeDao;
@Override
@Transactional
public List<Employee> findAll() {
    return employeeDao.findAll();
}
}
Here is the DAO class
package sagala.rest.boot.remade.dao;
import java.util.List;
import javax.persistence.EntityManager;
import org.hibernate.Session;
import org.hibernate.query.Query;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
import sagala.rest.boot.remade.entity.Employee;
@Repository
public class EmployeeDaoImpl implements EmployeeDao {
@Autowired
private EntityManager entityManager;
@Override
public List<Employee> findAll() {
    Session session =entityManager.unwrap(Session.class);
    Query<Employee> query =session.createQuery("from Employee", Employee.class);
    List<Employee> employees =query.getResultList();
    return employees;
}
}
Here is the entity class
package sagala.rest.boot.remade.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="employee")
public class Employee {
@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 Employee() {
}
public Employee(String firstName, String lastName, String email) {
    this.firstName = firstName;
    this.lastName = lastName;
    this.email = email;
}
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;
}
}
Here is the POM file
<?xml version="1.0" encoding="UTF-8"?>
<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 
https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.2.6.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>sagala</groupId>
<artifactId>rest.boot.remade</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>rest.boot.remade</name>
<description>Demo project for Spring Boot</description>
<properties>
    <java.version>1.8</java.version>
    <maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>
</properties>
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
        <exclusions>
            <exclusion>
                <groupId>org.junit.vintage</groupId>
                <artifactId>junit-vintage-engine</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
</dependencies>
<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>
</project>
Here is the application properties
spring.datasource.url=jdbc:mysql://localhost:3306/employee_directory?useSSL=false&serverTimezone=UTC spring.datasource.username=spring******* spring.datasource.password=spring*******
If anyone can help me. Thanks
