多对对的映射，可以用学生和课程进行演示。一个学生可以选择多个课程，一个课程又对应了多个学生

定义学生类

class Stu{

private String name;

private String num;

private Course[] course;

public Stu() {}

public Stu(String name,String num) {

this.name = name;

this.num = num;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getNum() {

return num;

}

public void setNum(String num) {

this.num = num;

}

public Course[] getCourse() {

return course;

}

public void setCourse(Course[] course) {

this.course = course;

}

public String getInfo() {

return "姓名 :"+name+" 学号 :"+num;

}

}

定义课程 类

class Course{

private String name;

private Stu[] stu;

public Course() {}

public Course(String name) {

this.name = name;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public Stu[] getStu() {

return stu;

}

public void setStu(Stu[] stu) {

this.stu = stu;

}

public String getInfo() {

return "课程 :"+name;

}

}

在main方法测试

首先定义Stu和Course对象，分别有三个

Stu s1 = new Stu("张三","001");

Stu s2 = new Stu("李四","002");

Stu s3 = new Stu("王五","003");

Course c1 = new Course("Java");

Course c2 = new Course("php");

Course c3 = new Course("Python");

设置彼此的关系，每个对象都有多个对象对应

//设置学生和课程的关系

s1.setCourse(new Course[]{c1,c2});

s2.setCourse(new Course[]{c1,c3});

s3.setCourse(new Course[]{c2,c3});

//相应的课程设置与学生的关系

c1.setStu(new Stu[]{s1,s2});

c2.setStu(new Stu[]{s1,s3});

c3.setStu(new Stu[]{s2,s3});

根据学生，获取课程信息

System.out.println(s1.getInfo()+" 同学选择的课程有");

for(int i=0; i

System.out.println(s1.getCourse()[i].getInfo());

}

运行

根据课程，获取学生信息

System.out.println(c2.getInfo()+" 选择这门课程的学生信息");

for(int i=0; i

System.out.println(c2.getStu()[i].getInfo());

}

运行