1）实现服务层：定义教师查询、班级查询、学生查询相关接口，并分别实现对应的接口；

好的，我来给你演示一下如何实现教师查询、班级查询和学生查询相关接口。

首先，我们定义三个接口：`TeacherService`、`ClassService`和`StudentService`。

public interface TeacherService {
    Teacher getTeacherById(int id);
    List<Teacher> getTeachersByDepartment(String department);
}

public interface ClassService {
    List<Class> getClassesByGrade(int grade);
    List<Class> getClassesByTeacher(int teacherId);
}

public interface StudentService {
    List<Student> getStudentsByClass(int classId);
    List<Student> getStudentsByTeacher(int teacherId);
}

接着，我们分别实现这些接口。

@Service
public class TeacherServiceImpl implements TeacherService {
    @Autowired
    private TeacherDao teacherDao;

    @Override
    public Teacher getTeacherById(int id) {
        return teacherDao.getTeacherById(id);
    }

    @Override
    public List<Teacher> getTeachersByDepartment(String department) {
        return teacherDao.getTeachersByDepartment(department);
    }
}

@Service
public class ClassServiceImpl implements ClassService {
    @Autowired
    private ClassDao classDao;

    @Override
    public List<Class> getClassesByGrade(int grade) {
        return classDao.getClassesByGrade(grade);
    }

    @Override
    public List<Class> getClassesByTeacher(int teacherId) {
        return classDao.getClassesByTeacher(teacherId);
    }
}

@Service
public class StudentServiceImpl implements StudentService {
    @Autowired
    private StudentDao studentDao;

    @Override
    public List<Student> getStudentsByClass(int classId) {
        return studentDao.getStudentsByClass(classId);
    }

    @Override
    public List<Student> getStudentsByTeacher(int teacherId) {
        return studentDao.getStudentsByTeacher(teacherId);
    }
}

在实现中，我们使用了`@Autowired`注解来自动装配Dao层组件，实现了各个接口中的方法。

最后，我们需要在配置文件中声明这些组件。

<context:component-scan base-package="com.example.service"/>
<context:component-scan base-package="com.example.dao"/>

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
    <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
    <property name="url" value="jdbc:mysql://localhost:3306/test"/>
    <property name="username" value="root"/>
    <property name="password" value="123456"/>
</bean>

<bean id="sessionFactory" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <property name="packagesToScan" value="com.example.entity"/>
    <property name="hibernateProperties">
        <props>
            <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
            <prop key="hibernate.show_sql">true</prop>
            <prop key="hibernate.format_sql">true</prop>
        </props>
    </property>
</bean>

<bean id="transactionManager" class="org.springframework.orm.hibernate5.HibernateTransactionManager">
    <property name="sessionFactory" ref="sessionFactory"/>
</bean>

<tx:annotation-driven/>

在这个例子中，我们使用了`<context:component-scan>`标签来扫描`com.example.service`和`com.example.dao`包下的类，并声明了数据源、SessionFactory和事务管理器等组件。

以上就是实现服务层，定义教师查询、班级查询、学生查询相关接口，并分别实现对应的接口的方法。希望对你有所帮助。