java练习-读取写入文件、数组排序

需求：

/*
    文本文件中有以下的数据：
        2-1-9-4-7-8
    将文件中的数据进行排序，变成以下的数据：
        1-2-4-7-8-9
*/

package com.example.ss_0203_array.test.test_0901;

import java.io.*;
import java.util.*;
import java.util.stream.Stream;

public class test1 {
    public static void main(String[] args) {
        File file = new File("F:\\阿里云盘下载\\Java入门到起飞-2\\day28-IO（字节流&字符流）\\代码\\AAA.txt");

        try {
            FileReader fr = new FileReader("F:\\阿里云盘下载\\Java入门到起飞-2\\day28-IO（字节流&字符流）\\代码\\AAA.txt");
            StringBuilder str = new StringBuilder();
            int ch;
            while ((ch = fr.read()) != -1) {
                str.append((char) ch);
            }
            String s = str.toString();
            String[] arrStr = s.split("-");

            ArrayList<Integer> list = new ArrayList<>();
            for (String s1 : arrStr) {
                list.add(Integer.parseInt(s1));
            }
            Collections.sort(list);

            FileWriter fw = new FileWriter("F:\\阿里云盘下载\\Java入门到起飞-2\\day28-IO（字节流&字符流）\\代码\\AAA.txt");
            for (int i = 0; i < list.size(); i++) {
                if (i == list.size() - 1) {
                    fw.write(list.get(i) + "");
                } else {
                    fw.write(list.get(i) + "-");
                }
            }
            fw.close();

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

　　

实现方式2：

package com.example.ss_0203_array.test.test_0901;

import java.io.*;
import java.util.*;
import java.util.stream.Stream;

public class test1 {
    public static void main(String[] args) {
        File file = new File("F:\\阿里云盘下载\\Java入门到起飞-2\\day28-IO（字节流&字符流）\\代码\\AAA.txt");

        try {
            FileReader fr = new FileReader("F:\\阿里云盘下载\\Java入门到起飞-2\\day28-IO（字节流&字符流）\\代码\\AAA.txt");
            StringBuilder str = new StringBuilder();
            int ch;
            while ((ch = fr.read()) != -1) {
                str.append((char) ch);
            }
            fr.close();

            Integer[] arr = Arrays.stream(str.toString().split("-"))
                    .map(Integer::parseInt)
                    .sorted()
                    .toArray(Integer[]::new);

            FileWriter fw = new FileWriter("F:\\阿里云盘下载\\Java入门到起飞-2\\day28-IO（字节流&字符流）\\代码\\AAA.txt");


            String arrstr = Arrays.toString(arr).replace(", ","-").replace("[","").replace("]","");
            fw.write(arrstr);
            fw.close();

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}