schoolclass.java

来自「基础性的JAVA源代码」· Java 代码 · 共 60 行

package exec.day1002;

import java.util.HashMap;
import java.util.HashSet;

public class SchoolClass {
	private String name;//班级名
	private HashSet allStudents;//班级内所有学生
	public SchoolClass(String name){
		this.name = name;
		allStudents = new HashSet();
	}
	
	public String getName(){
		return name;
	}
	public void addStudent(Student s){
		allStudents.add(s);
	}
	public void removeStudent(String name){
		Student s = new Student(name);
		allStudents.remove(s);
	}
	
	public HashMap getSelectedCourses(){
		HashMap map = new HashMap();
		//遍历班级内所有学生
		for(Object obj:allStudents){
			Student s = (Student)obj;
			//遍历该学生选修的所有课程
			for(Object o:s.getSelectedCourses()){
				Course c = (Course)o;
				//如果该课程已经在统计结果中
				if(map.containsKey(c.getName())){
					//取出原有选课人数，并加1
					int i = ((Integer)map.get(c.getName())).intValue();
					map.put(c.getName(), new Integer(i+1));
				}else{
					map.put(c.getName(),new Integer(1));
				}
			}
		}
		return map;
	}
}