L4_2

import java.io.BufferedReader;import java.io.InputStreamReader;import java.util.ArrayList;public class L4_2 {public static void main(String[] args) throws Exception {Spgl shipin = new Spgl();//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("添加食品请安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("删除食品请安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("");String bh = sr.readLine();System.out.println("请输入新的价格");float jg = Float.parseFloat(sr.readLine());shipin.sqjg(bh, jg);}else if(str.equals("4")){System.out.println("");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");}}}}//食品类class Sp{private String bianhao;private String mingcheng;private float jiage;Sp(String bianhao, String mingcheng, float jiage){this.bianhao = bianhao;this.mingcheng = mingcheng;this.jiage = jiage;}public String getBianhao(){return bianhao;}public void setBianhao(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;}}//食品管理类class Spgl{private ArrayList aa = null;Spgl(){aa = new ArrayList();  //把new集合类对象放在管理类的构造方法中   //等于在new管理类对象的时候直接new了集合类对象}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<aa.size(); i ++){Sp sp = (Sp)aa.get(i);if(sp.getBianhao().equals(bh)){System.out.println("该食品的信息为：");System.out.println("食品编号：" + bh);System.out.println("食品名称：" + sp.getMingcheng());System.out.println("食品价格：" + sp.getJiage());break;}}if(i == aa.size()){System.out.println("对不起，无此食品！");}}public void sqjg(String bh, float jg){int i;for(i = 0; i<aa.size(); i++){Sp sp = (Sp)aa.get(i);if(sp.getBianhao().equals(bh)){sp.setJiage(jg);System.out.println("修改食品价格成功！");break;}}if(i == aa.size()){System.out.println("对不起，没能找到相应的食品，修改");}}public void delsp(String bh){int i;if(aa.size() == 0){System.out.println("对不起，仓库中已没有任何食品！");}for(i = 0; i<aa.size(); i++){Sp sp = (Sp)aa.get(i);if(sp.getBianhao().equals(bh)){aa.remove(i);System.out.println("删除食品成功！");break;}}if((i == aa.size()) && (aa.size() != 0)){System.out.println("对不起，没有该食品！");}}}