Java 需要一个找不到的jakarta.sistence.EntityManager类型的Bean

我正在try 编译我的Spring Boot项目，但由于错误required a bean of type 'jakarta.persistence.EntityManager' that could not be found.the error is in TypeHunterDAOJpaImplementation.java，我在运行应用程序时遇到了问题.

• application.properties

# PostgreSQL
spring.datasource.url=jdbc:postgresql://localhost:5432/my_database
spring.datasource.username=postgres
spring.datasource.password=12345678
spring.datasource.driver-class-name=org.postgresql.Driver
spring.jpa.hibernate.ddl-auto=update
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect

• TypeHunter.java个

import jakarta.persistence.*;

@Entity
@Table(name="type_hunters")
public class TypeHunter {

    @Id
    @GeneratedValue (strategy = GenerationType.IDENTITY)
    @Column(name="id")
    private int id;

    @Column(name="description")
    private String description;

    public TypeHunter() {  // No-arg constructor for JPA

    }

    public TypeHunter(int id, String description) {
        this.id = id;
        this.description = description;
    }

    public int getId() { return id; }
    public void setId(int id) { this.id = id; }
    public String getDescription() { return description; }
    public void setDescription(String description) { this.description = description; }
}

• TypeHunterDAO.java个

import java.util.List;

public interface TypeHunterDAO {

    List<TypeHunter> findAll();

}

• TypeHunterDAOJpaImplementation.java个

import jakarta.persistence.EntityManager;
import jakarta.persistence.PersistenceContext;
import jakarta.persistence.TypedQuery;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
import java.util.List;

@Repository
public class TypeHunterDAOJpaImplementation implements TypeHunterDAO {

    @PersistenceContext
    private EntityManager entityManager;

    @Autowired
    public TypeHunterDAOJpaImplementation(EntityManager theEntityManager){
        entityManager = theEntityManager;
    }

    @Override
    public List<TypeHunter> findAll() {
        if (entityManager == null) throw new IllegalStateException("EntityManager does not work correctly.");
        TypedQuery<TypeHunter> query = entityManager.createQuery("from TypeHunter", TypeHunter.class);
        return query.getResultList();
    }

}

• TypeHunterREST.java个

import com.user.springboot3.project.DAO.TypeHunterDAO;
import com.user.springboot3.project.Entity.TypeHunterHunter;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;

@RequestMapping("/api")
@RestController
public class TypeHunterRest {

    private TypeHunterDAO type_hunter;

    public TypeHhnterRest(TypeHunterDAO typeHunterDAO) {
        this.type_hunter = typeHunterDAO;
    }

    @GetMapping("/type-hunter")
    public List<TypeHunter> findAll() {
        return type_hunter.findAll();
    }
}

建议的操作为Consider defining a bean of type 'jakarta.persistence.EntityManager' in your configuration.

在我的pom.xml人中有:

        <dependency>
            <groupId>jakarta.persistence</groupId>
            <artifactId>jakarta.persistence-api</artifactId>
            <version>3.1.0</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>5.6.6.Final</version>
        </dependency>

我想，这肯定起作用了.