public class Student {

    private Integer stuid;

    private String stuname;

    private String stuaddress;

    //植入一个Teacher集合，代表一名学员可以被多名教员教课

    private List<Teacher> teachers;

    public Integer getStuid() {

        return stuid;

    }

    public void setStuid(Integer stuid) {

        this.stuid = stuid;

    }

    public String getStuname() {

        return stuname;

    }

    public void setStuname(String stuname) {

        this.stuname = stuname;

    }

    public String getStuaddress() {

        return stuaddress;

    }

    public void setStuaddress(String stuaddress) {

        this.stuaddress = stuaddress;

    }

    public List<Teacher> getTeachers() {

        return teachers;

    }

    public void setTeachers(List<Teacher> teachers) {

        this.teachers = teachers;

    }

}

public class Teacher {

    private Integer tid;

    private String tname;

    //植入学员集合，代表一名教员授课多名学生

    private List<Student> students;

    public Integer getTid() {

        return tid;

    }

    public void setTid(Integer tid) {

        this.tid = tid;

    }

    public String getTname() {

        return tname;

    }

    public void setTname(String tname) {

        this.tname = tname;

    }

    public List<Student> getStudents() {

        return students;

    }

    public void setStudents(List<Student> students) {

        this.students = students;

    }

}

//多对多  查询所有学生信息 以及授课老师

    public List<Student> getStudentInfo();

<!--多对多-->

    <resultMap id="studentAndTeacher" type="com.marketsys.entity.Student">

        <id column="stuid" property="stuid"/>

        <collection property="teachers" ofType="com.marketsys.entity.Teacher">

            <id column="tid" property="tid"/>

        </collection>

    </resultMap>

    <select id="getStudentInfo" resultMap="studentAndTeacher">

        select * from student,teacher,stu_t where student.stuid=stu_t.stuid and teacher.tid=stu_t.tid

    </select>

SqlSession sqlSession= MybatisUtil.getSqlSession();
URoleTestDao mapper=sqlSession.getMapper(URoleTestDao.class);

//多对多

    @Test

    public void test3(){

        List<Student> studentInfo = mapper.getStudentInfo();

        for (Student stu:studentInfo) {

            System.out.println("学生："+stu.getStuname());

            for (Teacher teacher:stu.getTeachers()) {

                System.out.print("\t教员："+teacher.getTname());

            }

        }

    }