薪资管理系统（Java面向对象思想）

package com.test3;
import java.util.*;
import java.io.*;
/**
 * @author qingfeng
 * 重要思想：面向对象思想（添加员工管理类）
 * 功能：公司职员薪水管理系统
 */
public class SalarySystem {

    public static void main(String[] args) throws IOException {

        ClerkManager cm = new ClerkManager();//创建员工管理类

        InputStreamReader isr = new InputStreamReader(System.in);
        BufferedReader br = new BufferedReader(isr);

        while(true)
        {
            //简易菜单
            System.out.println("公司职员薪水管理系统");
            System.out.println("---------------------------------------");
            System.out.println("1.添加新员工");
            System.out.println("2.根据工号显示该员工的信息");
            System.out.println("3.显示所有员工信息");
            System.out.println("4.修改员工的薪水");
            System.out.println("5.根据工号删除该员工的信息");
            System.out.println("6.根据薪资由低到高排序");
            System.out.println("7.统计员工的平均工资、最高工资和最低工资");
            System.out.println("---------------------------------------");
            System.out.println("请选择序号：");

            String no = br.readLine();

            if(no.equals("1")){
                System.out.println("添加新员工：");
                System.out.println("请输入姓名:");
                String name = br.readLine();

                System.out.println("请输入性别:");
                String sex = br.readLine();

                System.out.println("请输入年龄:");//如何用InputStreamReader来输入一个int型的数据
                Scanner sc = new Scanner(System.in);
                int age = sc.nextInt();

                System.out.println("请输入工号:");
                String clerkNo = br.readLine();

                System.out.println("请输入薪资:");
                float salary = Float.parseFloat(br.readLine());

                Clerk clerk = new Clerk(name, sex, age, clerkNo, salary);//创建员工对象并且调用构造方法初始化
                cm.addClerk(clerk);//调用“添加新员工”方法

            }else if(no.equals("2")){
                System.out.println("请输入员工号:");
                String clerkNo = br.readLine();//接收输入的工号
                cm.showInfo(clerkNo);

            }else if(no.equals("3")){
                System.out.println("显示所有员工信息:");
                cm.showAllInfo();

            }else if(no.equals("4")){
                System.out.println("修改员工的薪水:");
                System.out.println("输入员工工号:");
                String clerkNo = br.readLine();//接收输入的工号
                System.out.println("修改员工薪资:");
                String sal = br.readLine();
                float salary = Float.parseFloat(sal);
                cm.modifySal(clerkNo, salary);

            }else if(no.equals("5")){
                System.out.println("根据工号删除该员工的信息:");
                System.out.println("输入员工工号:");
                String clerkNo = br.readLine();//接收输入的工号
                cm.deleteInfo(clerkNo);

            }else if(no.equals("6")){
                System.out.println("根据薪资由低到高排序");
                cm.Qsort(0, cm.al.size()-1);
                cm.showAllInfo();
            }else if(no.equals("7")){
                System.out.println("统计员工的平均工资、最高工资和最低工资:");
                cm.calSalary();
            }else if(no.equals("8")){
                System.exit(0);
            }else{
                System.out.println("输入不合法！");
            }
        }

    }
}
//员工管理类（非常重要！面向对象）
class ClerkManager
{
    //成员属性
    ArrayList al = null;

    //构造方法：初始化 不断创造新对象
    public ClerkManager()
    {
        al = new ArrayList();//注意写法！！
    }

    //成员方法
    //添加新员工!
    public void addClerk(Clerk clerk) //注意用增加的对象的引用作为参数！
    {
        al.add(clerk); //ArrayList添加方法用add()方法！
    }

    //根据工号显示该员工的信息
    public void showInfo(String no)
    {
        int flag = 0;
        for(int i=0; i<al.size(); i++)
        {
            Clerk clerk= (Clerk)al.get(i);
            if(clerk.getNo().equals(no))
            {
                flag = 1;
                System.out.println("clerk"+(i+1)+"的信息是：");
                System.out.print("姓名:"+clerk.getName());
                System.out.print("  性别:"+clerk.getSex());
                System.out.print("  年龄:"+clerk.getAge());
                System.out.print("  工号:"+clerk.getNo());
                System.out.println("  薪资:"+clerk.getSalary());
            }
        }
        if(flag == 0)
            System.out.println("找不到所查工号！");
    }

    //显示所有员工信息
    public void  showAllInfo()
    {
        for(int i=0; i<al.size(); i++)
        {
            Clerk clerk= (Clerk)al.get(i);
            System.out.println("clerk"+(i+1)+"的信息是：");

            System.out.print("姓名:"+clerk.getName());
            System.out.print("  性别:"+clerk.getSex());
            System.out.print("  年龄:"+clerk.getAge());
            System.out.print("  工号:"+clerk.getNo());
            System.out.println("  薪资:"+clerk.getSalary());
        }
    }

    //修改员工的薪水
    public void  modifySal(String no, float sal) //员工编号   最新的薪资
    {
        int flag = 0;
        for(int i=0; i<al.size(); i++)
        {
            Clerk clerk= (Clerk)al.get(i);
            if(clerk.getNo().equals(no))
            {
                flag = 1;
                clerk.setSalary(sal);
            }
        }
        if(flag == 0)
            System.out.println("找不到所查工号！");
    }

    //根据工号删除该员工的信息
    public void deleteInfo(String no)
    {
        int flag = 0;
        for(int i=0; i<al.size(); i++)
        {
            Clerk clerk= (Clerk)al.get(i);
            if(clerk.getNo().equals(no))
            {
                flag = 1;
                al.remove(i);
            }
        }
        if(flag == 0)
            System.out.println("找不到所查工号！");
    }

    //根据薪资由低到高排序
    public void Qsort(int left, int right)
    {
        int i = left;
        int j = right;

        if(i < j)//递归结束条件
        {
            Clerk clerk = (Clerk)al.get(left);
            float key  = clerk.getSalary();
            while(i<j)//一趟快速排序
            {
                while(i<j && ((Clerk)al.get(j)).getSalary() >= key)
                {
                    j--;
                }
                if(i<j)
                {
                    al.set(i,al.get(j));
                    i++;
                }
                while(i<j && ((Clerk)al.get(i)).getSalary() <= key)
                {
                    i++;
                }
                if(i<j)
                {
                    al.set(j, al.get(i));
                }
            }
            al.set(i, clerk);
            Qsort(left, i-1);
            Qsort(i+1, right);
        }
    }

    //统计员工的平均工资、最高工资和最低工资
    public void calSalary()
    {
        float totalSal = 0;
        float minSal = ((Clerk)al.get(0)).getSalary();
        float maxSal = ((Clerk)al.get(0)).getSalary();

        for(int i=0; i<al.size(); i++)
        {
            Clerk clerk = (Clerk)al.get(i);
            totalSal += clerk.getSalary();
            if(minSal > clerk.getSalary())
            {
                minSal = clerk.getSalary();
            }
            if(maxSal < clerk.getSalary())
            {
                maxSal = clerk.getSalary();
            }
        }
        System.out.println(al.size()+"个人的平均薪资为：" + totalSal/al.size());
        System.out.println(al.size()+"个人的最低薪资为："+minSal);
        System.out.println(al.size()+"个人的最高薪资为："+maxSal);
    }
}
//员工类
class Clerk
{
    private String name;
    private String sex;
    private int age;
    private String no;
    private float salary;

    public Clerk(String name, String sex, int age, String no, float salary)
    {
        this.name = name;
        this.sex = sex;
        this.age = age;
        this.no = no;
        this.salary = salary;
    }

    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 int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getNo() {
        return no;
    }

    public void setNo(String no) {
        this.no = no;
    }

    public float getSalary() {
        return salary;
    }

    public void setSalary(float salary) {
        this.salary = salary;
    }
}