package 學生成績管理;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.util.ArrayList;import java.util.List;import java.util.Scanner;class Sp { private String bianhao; private String mingcheng; private double jiage; Sp(String bianhao,String mingcheng,double 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 double getJiage() { return jiage; } public void setJiage(double jiage) { this.jiage = jiage; }}class Spg{ ArrayList<Object> aa=null; Scanner in=null; Spg() { aa=new ArrayList(); in=new Scanner(System.in); } public void addsp(Sp Sp) { aa.add(Sp); System.out.println("增加成功"); } public void spxx(String bh) { int i; int c=aa.size(); for(i=0;i<c;i++) { Sp sr=(Sp)aa.get(i); if(sr.getBianhao().equals(bh)) { System.out.println("信息如下："); System.out.println("食品編號:"+sr.getBianhao()); System.out.println("食品名稱:"+sr.getMingcheng()); System.out.println("食品價格:"+sr.getJiage()); } } if(i==c) { System.out.println("輸入有誤"); } } public void delsp(String bh) { int i; if(aa.size()==0) { System.out.println("沒有信息"); } for(i=0;i<aa.size();i++) { Sp sr=(Sp)aa.get(i); if(sr.getBianhao().equals(bh)) { aa.remove(i); } } if(i==aa.size()&&aa.size()!=0) { System.out.println("輸入有誤"); } } public void setsp(String bh) { int i; for(i=0;i<aa.size();i++) { Sp sr=(Sp)aa.get(i); if(sr.getBianhao().equals(bh)) { System.out.println("請輸入新的名稱"); String c=in.next(); sr.setBianhao(c); System.out.println("請輸入新的價格"); double a=in.nextDouble(); sr.setJiage(a); //aa.remove(i,bh); } } if(i==aa.size()&&aa.size()!=0) { System.out.println("輸入有誤"); } } public void exitsp() { System.out.println("謝謝使用"); System.exit(0); } public void addsp(String bh, String mg, double jg) { // TODO Auto-generated method stub }}public class Lianxi2{ public static void main(String []args) throws IOException { Spg gl=new Spg(); BufferedReader sr=new BufferedReader(new InputStreamReader(System.in)); while(true) { System.out.println("請按如下提示操作："); System.out.println("按1增添食品種類"); System.out.println("按2查詢食品"); System.out.println("按3刪除食品"); System.out.println("按4修改食品"); System.out.println("按0退出系統(tǒng)"); String srt=sr.readLine(); if(srt.equals("1")) { System.out.println("請?zhí)砑邮称访Q"); String mg=sr.readLine(); System.out.println("請?zhí)砑邮称肪幪?); String bh=sr.readLine(); System.out.println("請?zhí)砑邮称穬r格"); double jg=Double.parseDouble(sr.readLine()); gl.addsp(bh,mg,jg); }else if(srt.equals("2")) { System.out.println("請輸入食品編號"); String bh=sr.readLine(); gl.spxx(bh); }else if(srt.equals("3")) { System.out.println("請輸如食品編號"); String bh=sr.readLine(); gl.delsp( bh); }else if(srt.equals("4")) { System.out.println("請輸如食品編號"); String bh=sr.readLine();gl.setsp( bh);這里的方法發(fā)現(xiàn)根本無法使用，求大神指點錯誤 }else if(srt.equals("0")) {; gl.exitsp( ); } } }}