Java-->吧把txt中的所有字符按照码表值排序

package com.dragon.java.filesort;

import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;

/*
 * 将day19-笔记.txt中的所有字符按照码表值排序, 存入另一个文件中
 */
public class Test {
    public static void main(String args[]) {
        FileReader fr = null;
        FileWriter fw = null;
        ArrayList<Character> list = new ArrayList<>();
        try {
            fr = new FileReader(
                    "C:/Users/xy/Desktop/文件/Java/Java/DailyCode/08-14/src/com/dragon/java/days.txt");
            fw = new FileWriter(
                    "C:/Users/xy/Desktop/文件/Java/Java/DailyCode/08-14/src/com/dragon/java/days01.txt");
            char[] buffer = new char[1024];
            while (true) {
                int temp = fr.read(buffer, 0, buffer.length);
                if (temp == -1) {
                    break;
                } else {
                    for (char c : buffer) {
                        if (c == ‘\r‘ || c == ‘\n‘ || c == ‘ ‘ || c == ‘\t‘) {
                            continue;
                        }
                        System.out.print(c);
                                                 // 在这里就出现了多余的空间
                                                list.add(c);
                    }
                }
            }
                        // 按理说trimToSize 方法不应该可以去掉多余空间的么?
                 list.trimToSize(); // 将此 ArrayList 实例的容量调整为列表的当前大小。
            // List<Integer> nullArr = new ArrayList<Integer>();
            // nullArr.add(null);
            // list.removeAll(nullArr);
                        // 用null 也去不掉啊...
            Collections.sort(list);
            char[] buffer1 = new char[list.size()];
            for (int i = 0; i < list.size(); i++) {
                buffer1[i] = list.get(i);
            }
            fw.write(buffer1, 0, buffer1.length);
        } catch (IOException e) {
            System.out.println(e);
        } finally {
            try {
                fr.close();
                fw.close();
            } catch (IOException e) {
                System.out.println(e);
            }
        }
    }

        // 比较器比较字符的大小(可自主修改)
    public static class MyCompartor implements Comparator<Character> {

        @Override
        public int compare(Character o1, Character o2) {
            // if (o1 == ‘\n‘ || o2 == ‘\n‘) {
            // return 0;
            // }
            return o1 - o2;
        }
    }

}