java编写食品管理程序

package test;
import java.util.*;
import java.io.*;

public class L4_2 {
	public static void main(String[] args) throws Exception{
		Spg1 shipin=new Spg1();
		BufferedReader sr=new BufferedReader(new InputStreamReader(System.in));
        while(true){
			System.out.println("请按提示选择以下功能");
			System.out.println("添加食品请按1");
			System.out.println("查找食品信息请按2");
			System.out.println("修改食品价格请按3");
			System.out.println("删除食品请按4");
			System.out.println("退出请按0");
			
			String str=sr.readLine();
			if(str.equals("1")){
				System.out.println("请输入食品编号");
				String bh=sr.readLine();
				System.out.println("请输入食品名称");
				String mc=sr.readLine();
				System.out.println("请输入食品价格");
				float jg=Float.parseFloat(sr.readLine());
				
				Sp sp=new Sp(bh,mc,jg);
				shipin.addsp(sp);
			}
			else if(str.equals("2")){
				System.out.println("请输入食品编号");
				String bh=sr.readLine();
				shipin.spxx(bh);
			}
			else if(str.equals("3")){
				System.out.println("请输入食品编号");
				String bh=sr.readLine();
				System.out.println("请输入新的价格");
				float jg=Float.parseFloat(sr.readLine());
				shipin.spjg(bh, jg);
			}
			else if(str.equals("4")){
				System.out.println("请输入食品编号");
				String bh=sr.readLine();
				shipin.delsp(bh);
			}
			else if(str.equals("0")){
				System.out.println("感谢您的使用，再见！");
				System.exit(0);
			}
			else{
				System.out.println("输入有误！");
			}
        }
	}
}


class Sp
{
	private String bianhao;
	private String mingcheng;
	private float jiage;
	
	Sp(String bianhao,String mingcheng,float jiage){
		this.mingcheng=mingcheng;
		this.bianhao=bianhao;
		this.jiage=jiage;
	}
	public String getBianhao(){
		return bianhao;
	}
	public void setBiaohao(String bianhao){
		this.bianhao=bianhao;
	}
	public String getMingcheng(){
		return mingcheng;
	}
	public void setMingcheng(String mingcheng){
		this.mingcheng=mingcheng;
	}
	public float getJiage(){
		return jiage;
	}
	public void setJiage(float jiage){
		this.jiage=jiage;
	}
}


class Spg1
{
	private ArrayList aa=null;
	Spg1(){
		aa=new ArrayList();
	}
	public void addsp(Sp sp){
		aa.add(sp);
		System.out.println("添加新食品成功！");
	}
	
	public void spxx(String bh){
		int i;
		for(i=0;i