選課系統很有意思，學生選擇一門課程以后，這門課程就會添加到這個學生的選課列表里面，同時這名學生也添加到了選擇這門課程的學生列表里面，也就是學生和課程是雙向選擇的。
創建課程類Course，設置三個屬性分別為名稱、學分、學生名單。
Course
import java.util.ArrayList;
import java.util.List;
public class Course {
private String name;
private float grade;
private List<Student> allStudents;
public Course(String name,float grade){
this.setAllStudents(new ArrayList<Student>());
this.setGrade(grade);
this.setName(name);
}
public void addStu(Student student){
this.allStudents.add(student);
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public float getGrade() {
return grade;
}
public void setGrade(float grade) {
this.grade = grade;
}
public List<Student> getAllStudents() {
return allStudents;
}
public void setAllStudents(List<Student> allStudents) {
this.allStudents = allStudents;
}
}
創建學生類Student，設置三個屬性姓名、年齡、選課列表。
Student
import java.util.ArrayList;
import java.util.List;
public class Student {
private String name;
private int age;
private List<Course> allCourse;//一個學生可以選多門課
public Student(String name,int age){
this.setAge(age);
this.setAllCourse(new ArrayList<Course>());
this.setName(name);
}
public void addCourse(Course course){
this.allCourse.add(course);
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public List<Course> getAllCourse() {
return allCourse;
}
public void setAllCourse(List<Course> allCourse) {
this.allCourse = allCourse;
}
}
創建測試類TestCourse，在里面創建五個學生三門課程，并對他們互相選擇，并把每個學生選得課程添加到各自的選課列表，把選擇每門課程的學生添加到各科的學生列表，然后進行遍歷，學生的課程列表和課程的學生列表。
TestCourse
import java.util.Iterator;
public class TestCourse {
public static void main(String[] args) {
Student stu1 = new Student("張三",20);
Student stu2 = new Student("李四",21);
Student stu3 = new Student("王五",22);
Student stu4 = new Student("趙柳",23);
Student stu5 = new Student("孫琦",24);
Course c1 = new Course("Java se 基礎",2.0f);
Course c2 = new Course("Java se web",3.0f);
Course c3 = new Course("分布式開發",5.0f);
// 設置關系
stu1.addCourse(c1);
c1.addStu(stu1);
stu1.addCourse(c2);
c2.addStu(stu1);
stu2.addCourse(c2);
c2.addStu(stu2);
stu3.addCourse(c1);
c1.addStu(stu3);
stu3.addCourse(c2);
c2.addStu(stu3);
stu3.addCourse(c3);
c3.addStu(stu3);
stu4.addCourse(c3);
c3.addStu(stu4);
stu5.addCourse(c3);
c3.addStu(stu5);
System.out.println("學生姓名："+stu1.getName());
Iterator<Course> it1 = stu1.getAllCourse().iterator();
while(it1.hasNext()){
Course c = it1.next();
System.out.println("\t|-課程名稱："+c.getName()+",學分："+c.getGrade());
}
System.out.println("課程名稱："+c3.getName());
Iterator<Student> it2 = c3.getAllStudents().iterator();
while(it2.hasNext()){
Student s = it2.next();
System.out.println("\t|-學生姓名："+s.getName()+",年齡："+s.getAge());
}
}
}
結果顯示（只打印stu1和c1的列表）
posted on 2010-10-30 00:40
Mineralwasser 閱讀(164)
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