尝试从另一个项目编写相同的代码时出现了几个问题

Question

我java编程课的老师在他的网页上发布了一个他希望我们自己编写代码的例子。然而，当我试图在自己的实验室中重新创建相同的代码时，我遇到了几个错误。下面是代码:

public class StudentRepositoryImpl extends Repository<Student, Long> implements StudentRepositoryCustom {
private static final Logger log = LoggerFactory.getLogger(StudentRepositoryImpl.class);
public StudentRepositoryImpl()
{
    super(Student.class);
}
@Override
@Transactional
public List<Student> findAllWithLabsSqlQuery()
{
    log.trace("findAllWithLabsSqlQuery: method entered");
    HibernateEntityManager hibernateEntityManager = getEntityManager().unwrap(HibernateEntityManager.class);
    Session session = hibernateEntityManager.getSession();
    Query query = session.createSQLQuery("select distinct {s.*}, {sd.*}, {d.*}" +
            " from student s" +
            " left join student_lab sd on sd.student_id = s.id" +
            " left join lab d on d.id = sd.lab_id")
            .addEntity("s", Student.class)
            .addJoin("sd", "s.studentLabs")
            .addJoin("d", "sd.lab")
            .addEntity("s", Student.class)
            .setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);
    List<Student> students = query.list();
    log.trace("findAllWithLabsSqlQuery: students={}", students);
    return students;
}
@Override
@Transactional
public List<Student> findAllWithLabsJpql() {
    log.trace("findAllWithLabsJpql: method entered");
    javax.persistence.Query query = getEntityManager().createQuery("select distinct s from Student s" +
            " left join fetch s.studentLabs sd" +
            " left join fetch sd.lab d");
    List<Student> students = query.getResultList();
    log.trace("findAllWithLabsJpql: students={}", students);
    return students;
}
@Override
@Transactional
public List<Student> findAllWithLabsJpaCriteria() {
    log.trace("findAllWithLabsJpaCriteria: method entered");
    CriteriaBuilder criteriaBuilder = getEntityManager().getCriteriaBuilder();
    CriteriaQuery<Student> query = criteriaBuilder.createQuery(Student.class);
    query.distinct(Boolean.TRUE);
    Root<Student> from = query.from(Student.class);
    Fetch<Student, StudentLab> studentLabFetch = from.fetch(Student_.studentLabs, JoinType.LEFT);
    studentLabFetch.fetch(StudentLab_.discipline, JoinType.LEFT);
    List<Student> students = getEntityManager().createQuery(query).getResultList();
    log.trace("findAllWithLabsJpaCriteria: students={}", students);
    return students;
}

}

我面临的错误是:

1 -超级方法("Cannot resolve method 'super(java.lang.Class)'")

2 -每个getEntityManager函数("不能解析方法'getEntityManager ")

3 - "Student_"one_answers"StudentLab_" ("Cannot resolve symbol")

在他的项目中，相同的代码，尽管类名修改，工作。是否与.iml或pom.xml文件有关?

下面是导入的库:

    import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.jpa.HibernateEntityManager;
import org.hibernate.jpa.internal.EntityManagerFactoryImpl;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.transaction.annotation.Transactional;
import javax.persistence.criteria.*;
import java.util.List;
import ro.ubb.books.core.model.*;
import ro.ubb.books.core.repository.*;

Answer 1

如果您也复制了pom.xml，请尝试运行以下命令。

mvn clean package