系统运行不对怎么办啊

Question

show不出来文件内容，是写的有什么问题吗？服了呀改也改不对

Answer 1

package com.star.cmsdemo02;

/*
 * @Author: wangjiawei
 * @Date: 2024/9/5 22:39
 * @Description:
 */

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;
public class productView {
    private productlist productlist = new productlist(200);

    public void printmenu() {
        System.out.println("------品牌鞋信息管理系统------");
        System.out.println("info:----品牌鞋基本信息管理----");
        System.out.println("quit:----退出系统");
        System.out.println("---------------------------");
        while (true) {
            Scanner sc = new Scanner(System.in);
            System.out.print("main>");
            String choice = sc.next();
            switch (choice) {
                case "info":
                    System.out.println("---品牌鞋基本信息管理---");
                    System.out.println("show:----显示品牌信息");
                    System.out.println("add:-----添加品牌信息");
                    System.out.println("delete:--删除品牌信息");
                    System.out.println("modify:--修改品牌信息");
                    System.out.println("save:--导出文件");
                    System.out.println("load：---导入文件");
                    System.out.println("quit:---退出-----");
                    System.out.println("------------------");
                    while (true) {
                        sc = new Scanner(System.in);
                        System.out.print("info>");
                        String choice1 = sc.next();
                        switch (choice1) {
                            case "show":
                                System.out.println("---展示产品信息---");
                                show();
                                break;
                            case "add":
                                System.out.println("---添加产品信息---");
                                add();
                                break;
                            case "delete":
                                System.out.println("---删除品牌信息---");
                                delete();
                                break;
                            case "modify":
                                System.out.println("---修改品牌信息---");
                                modify();
                                System.out.println("---修改品牌信息---");
                                modify();
                                break;
                            case "save":
                                System.out.println("---导出文件---");
                                exportFile();
                                break;
                            case "load":
                                System.out.println("---导入文件---");
                                try {
                                    load();
                                } catch (IOException e) {
                                    throw new RuntimeException(e);
                                }
                                break;
                            case "return":
                                return;
                        }
                    }
                case "quit":
                    System.exit(0);

            }
        }
    }

    public void process() {
        printmenu();
        while (true) {
            Scanner sc = new Scanner(System.in);
            System.out.print("info>");
            String choice = sc.next();
            switch (choice) {
                case "add":
                    add();
                    break;
                case "delete":
                    delete();
                    break;
                case "modify":
                    modify();
                    break;
                case "load":
                    try {
                        load();
                    } catch (IOException e) {
                        throw new RuntimeException(e);
                    }
                    break;
                case "return":
                    return;

            }


        }

    }

    public static void main(String args[]) {
        productView st = new productView();
        st.process();
    }

    public int find(String id) {
        product[] pros =  productlist.getallproduct();
        int k = -1;
        for (int i = 0; i < pros.length; i++) {
            if (id.equals(pros[i].getId())) {
                k = i;
                break;
            }
        }
        return k;

    }

    public void add() {
        Scanner sc = new Scanner(System.in);
        System.out.println("序号");
        String id = sc.next();
        System.out.println("品牌名称");
        String name = sc.next();
        System.out.println("价钱");
        String price = sc.next();
        System.out.println("颜色");
        String colour = sc.next();
        System.out.println("产地");
        String producer = sc.next();
        product pro = new product(id, name, price, colour, producer);
        boolean flag = productlist.addproduct(pro);
        if (flag) {
            System.out.println("---添加成功---");
        } else {
            System.out.println("---添加失败---");
        }
    }

    public void delete() {
        System.out.println("请输入要删除的序号：");
        Scanner sc = new Scanner(System.in);
        String id = sc.next();
        int index = find(id);
        if (index == -1) {
            System.out.println("---该品牌鞋不存在---");
            return;
        }
        boolean flag = productlist.delproduct(index);
        if (flag) {
            System.out.println("---删除成功---");
        } else {
            System.out.println("---删除失败---");
        }
    }

    public void modify() {
        System.out.print("请输入要修改的序号：");
        Scanner sc = new Scanner(System.in);
        String id = sc.next();
        int index = find(id);
        if (index == -1) {
            System.out.println("---该品牌不存在---");
            return;
        }
        System.out.println("品牌名称");
        String name = sc.next();
        System.out.println("价钱");
        String price = sc.next();
        System.out.println("颜色");
        String colour = sc.next();
        System.out.println("产地");
        String producer = sc.next();
        product pro = new product(index);
        boolean flag = productlist.modifyproduct(index, pro);
        if (flag) {
            System.out.println("---修改成功---");
        } else {
            System.out.println("---修改失败---");
        }
    }

    public void show() {
        System.out.println("----品牌信息----");
        // product[] pros;
        product[] pros = productlist.getallproduct();

        // TODO 这里不应该是判断product.length == 0，你product里的length属性没赋初值且没用过默认是0,应该是判断product[]数组的长度
        if (pros.length == 0) {
            System.out.println("尚没有该品牌记录");
        } else {
            System.out.println("序号\t名称\t价钱\t颜色\t产地");
            for (int i = 0; i <= pros.length - 1; i++) {
                System.out.println(pros[i].getId() + "\t"
                        + pros[i].getName() + "\t"
                        + pros[i].getPrice() + "\t"
                        +pros[i].getColour() + "\t"
                        + pros[i].getProducer() + "\t");
            }
        }

        System.out.println("------------------------");
    }

    public void exportFile() {
        String filePath = "D:\\product.txt";
        product[] pros = productlist.getallproduct();
        try (BufferedWriter writer = new BufferedWriter(new FileWriter(filePath))) {
            writer.write("序号\t\t品牌名称\t\t价格\t\t颜色\t\t产地\n");
            for (int i = 0; i < pros.length; i++) {
                writer.write(pros[i].getId() + "\t\t\t"
                        + pros[i].getName() + "\t\t"
                        + pros[i].getPrice() + "\t\t"
                        + pros[i].getColour() + "\t\t"
                        + pros[i].getProducer() + "\n");
            }
            System.out.println("品牌信息已成功写入文件！");
        } catch (IOException e) {
            System.err.println("写入文件时发生错误：" + e.getMessage());
        }
    }

    public void load1() throws IOException{
        product s1 = new product("1001", "安踏","200￥", "白色","江西");
        productlist.addproduct(s1);

//        System.out.println("load()方法："+s1);
        product[] pros = productlist.getallproduct();
        for (product pro : pros) {
            System.out.println("load list：" + pro);
        }

    }
    public void load() throws IOException {
        Scanner sc = new Scanner(System.in);
        System.out.print("请输入要导入的文件名:");

//        String fn = sc.next();
        //文件路径得用"/"，不要用"\\"
        String fn = "E:/IdeaProjects/code/cms-demo02/src/test/java/com/star/cmsdemo02/a.txt";
        File file = new File(fn);

        System.out.println(file.exists());//true

        if (file.exists()) {
            BufferedReader br = new BufferedReader(new FileReader(fn));
            String str;
            // TODO 你while这句多了分号
            while ((str = br.readLine()) != null)
            {String id = str.split(",")[0];
                String name = str.split(",")[1];
                String price = str.split(",")[2];
                String colour = str.split(",")[3];
                String producer = str.split(",")[4];
                product s = new product(id, name,price, colour,producer);
                System.out.println("产品："+s.name);

                if (idExists(id)) {
                    System.out.println("---该顾客已存在---");
                } else {
                    productlist.addproduct(s);
                }
            }
            br.close();
            System.out.println("--导入成功--");
        } else {
            System.out.println("---要导入的文件不存在--");
        }
    }

    private boolean idExists(String id) {
        return false;
    }
    public class product {
        //这个静态属性没有初始化过 length默认等于0 show()方法中的(product.length == 0)判断恒等于true
        public static int length;

        private String id;
        private String name;
        private String price;
        private String colour;
        private String producer;

        //单参构造器
        public product(int i) {
            this.name = this.id;
            this.id = this.name;
            this.price= this.price;
            this.colour= this.colour;
            this.producer= this.producer;
        }

        //全参构造器
        public product(String id, String name, String price, String colour, String producer) {
            this.id = id;
            this.name = name;
            this.price= price;
            this.colour= colour;
            this.producer= producer;
        }


        public static product[] addproduct() {
            return new product[0];
        }

        product get(int i) {
            return new product(i);
        }
        public String getName(){
            return name;
        }
        public void setName(String name){
            this.name = name;
        }
        public String getPrice() {
            return price;
        }
        public void setPrice(String price){
            this.price= price;
        }
        public String getId() {
            return id;
        }
        public void setId(String id) {
            this.id = id;
        }
        public String getColour() {
            return colour;
        }
        public void setColour(String colour) {
            this.colour = colour;
        }
        public String getProducer() {
            return producer;
        }
        public void setProducer(String  producer) {
            this.producer = producer;
        }

        @Override
        public String toString() {
            return "Product{" +
                    "id='" + id + '\'' +
                    ", name=" + name +
                    ", price=" + price+
                    ", colour='" + colour + '\'' +
                    ",producer=" + producer +
                    '}';
        }


    }

//    public class productlist {
//        public static Object remove;
//        private product[] products;
//        private static int total = 0;
//
//        public productlist(int maxlength) {
//            products = new product[maxlength];
//        }
//
//        public boolean modifyproduct(int index, product pro) {
//            // TODO Auto-generated method stub
//            return false;
//        }
//
//        public product[] getallproduct() {
//            // TODO Auto-generated method stub
//            return null;
//        }
//
//        public static void remove(int i) {
//        }
//
//        public boolean addproduct(product pro) {
//            if (total >= products.length) {
//                return false;
//            }
//            products[total++] = pro;
//            return true;
//        }
//
//        public boolean delproduct(int index) {
//            if (total < 0 || index >= total) {
//                return false;
//
//            }
//            for (int i = index; i < total - 1; i++) {
//                products[i] = products[i++];
//            }
//            products[--total] = null;
//            return true;
//        }
//    }
    public class productlist {
        public static Object remove;
        private product[] products;
        private static int total = 0;

        public productlist(int maxlength) {
            products = new product[maxlength];
        }

        public static void remove(int i) {
        }

        public boolean addproduct(product pro) {
            if (total >= products.length) {
                return false;
            }
            products[total++] = pro;
            return true;
        }

        public boolean delproduct(int index) {
            if (total < 0 || index >= total) {
                return false;

            }
            for (int i = index; i < total - 1; i++) {
                products[i] = products[i++];
            }
            products[--total] = null;
            return true;
        }

        public boolean modifyproduct(int index, product pro) {
            if (index < 0 || index >= total) {
                return false;
            }
            products[index] = pro;
            return true;
        }

        public product[] getallproduct() {
            product[] pros = new product[total];
            for (int i = 0; i < total; i++) {
                pros[i] = products[i];
            }
            return pros;
        }
    }
}