Java代码程序问题

Question

 

Answer 1

package com.io;

import lombok.Data;

import java.io.*;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.stream.Collectors;

/**
 * @author LinQi
 * @version 1.0
 * @date 2021/6/28 9:52
 */
@Data
class Article {
    private Integer id;
    private String name;
    private Double prices;
    private Integer count;
}

class Demo {
    public static void main(String[] args) {
        List<Article> list = new ArrayList<>();
        String filePath = "d:/a.txt";
        File file = new File(filePath);
        BufferedReader reader = null;
        String tempString = null;
        String str = null;
        try {
            reader = new BufferedReader(new InputStreamReader(new FileInputStream(file), "UTF-8"));
            while ((tempString = reader.readLine()) != null) {
                str = tempString;
                Article article = new Article();
                String[] split = str.split(",");
                article.setId(Integer.parseInt(split[0]));
                article.setName(split[1]);
                article.setPrices(Double.parseDouble(split[2]));
                article.setCount(Integer.parseInt(split[3]));
                list.add(article);
            }
            reader.close();
        } catch (
                Exception e) {
            e.printStackTrace();
        } finally {
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        List<Article> collect = list.stream().sorted(Comparator.comparing(Article::getPrices).reversed()).collect(Collectors.toList());
        File files = new File("d:/price_order.txt");
        try {
            if (!files.exists()) {
                files.createNewFile();
            }
            OutputStream os = new FileOutputStream(files);
            for (Article article : collect) {
                String st = article.getId()+","+article.getName()+","+ article.getPrices()+","+ article.getCount();
                os.write(st.getBytes(StandardCharsets.UTF_8));
                os.write(("\r\n").getBytes());
            }
            os.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}