初学JAVA--方法

关于方法的使用

-以下是一个示例小程序-
-学生类的属性有学号、姓名、性别、语文、英语、数学等的成绩，实现方法有求总分，求平均分-
-班级类用SET集合实现增删查改以及排序等-
-最后在主函数调用-

学生类

package com.xuedao.model;

public class Student implements Comparable<Student> {
	
	private int id;
	private String name;
	private String sex;
	private double math;
	private double chinese;
	private double english;
	
	public Student() {
		super();
	}
	public Student(int id, String name, String sex, double math, double chinese, double english) {
		super();
		this.id = id;
		this.name = name;
		this.sex = sex;
		this.math = math;
		this.chinese = chinese;
		this.english = english;

}

//求总分
public double getTotal() {
	return math + english + chinese;
}
//求平均分
public double getAvg() {
	return getTotal()/3;
}

//和其他学生比较
public int compareTo(Student o) {
	if(this.getTotal() > o.getTotal()) {
		return 1;
		}else if(this.getTotal() < o.getTotal()) {
			return -1;
		}else if(chinese >o.getChinese()) {
			return 1;
		}else if(chinese <o.getChinese()) {
			return -1;
		}else if(math >o.getMath()) {
			return 1;
		}else if(math <o.getMath()) {
			return -1;
		}else {
			return 0;
		}
	}
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getSex() {
		return sex;
	}
	public void setSex(String sex) {
		this.sex = sex;
	}
	public double getMath() {
		return math;
	}
	public void setMath(double math) {
		this.math = math;
	}
	public double getChinese() {
		return chinese;
	}
	public void setChinese(double chinese) {
		this.chinese = chinese;
	}
	public double getEnglish() {
		return english;
	}
	public void setEnglish(double english) {
		this.english = english;
	}
	@Override
	public String toString() {
		return id+"\t"+name+"\t"+sex+"\t"+math+"\t"+chinese+"\t"+english+"\t"+getTotal()+"\t"+getAvg();
	}
	
	
}

班级类

package com.xuedao.model;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import java.util.TreeSet;

public class Classes {

	private String name;
	private Set<Student> stus;
	
	public void init(int n) {
		stus = new HashSet<Student>();
		for (int i = 0; i < n; i++) {
			Student s = new Student(i, "小"+i, ((int)(Math.random()*2))==1?"男":"女", (int)(Math.random()*30)+70, (int)(Math.random()*20)+60, (int)(Math.random()*10)+50);
			stus.add(s);
		}
	}
	
	//增
	public void add(Student s) {
		stus.add(s);
	}
	
	//删除
	public void delete(int id) {
		Iterator<Student> it = stus.iterator();
		while(it.hasNext()) {
			if(id == it.next().getId()) {
				it.remove();
				return;
			}
		}
	}
	
	//改
	public void modify(int id, Student s) {
		delete(id);
		add(s);
	}
	
	//查
	public Student get(int id) {
		Iterator<Student> it = stus.iterator();
		while(it.hasNext()) {
			Student next = it.next();
			if(id == next.getId()) {
				return next;
			}
		}
		return null;
	}
	
	//排序
	public void sort() {
		stus = new TreeSet<Student>(stus);
	}
	
	public void show() {
		System.out.println("所有学生的信息");
		for (Student s : stus) {
			System.out.println(s);
		}
		
	}
	
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public Set<Student> getStus() {
		return stus;
	}
	public void setStus(Set<Student> stus) {
		this.stus = stus;
	}
	
	
}

MainClass

package com.xuedao.model;

public class MainClass {

	public static void main(String[] args) {
		Classes c = new Classes();
		c.init(10);
		c.show();
		c.sort();
		c.show();
	}
}