请按照顺序排列并且写道文件b.txt中

Posted 2021-03-24 YRSWBY

/*
2.何事秋风悲画扇
4.却道故人心易变
1.人生若只如初见
3.等闲变却故人心
请按照顺序排列并且写道文件b.txt中
 */
public class Six {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new FileReader("20190815\\a.txt"));
        TreeMap<Integer,String> tm = new TreeMap<>();
        String line;
        while((line = br.readLine()) != null){//字符串等于，文件读取行数到不为Null为止
            String num = line.substring(0,1);//截取前面的编号
            tm.put(Integer.parseInt(num),line);
        }
        br.close();//关闭读取的流
        BufferedWriter bw = new BufferedWriter(new FileWriter("20190815\\b.txt"));
        Set<Map.Entry<Integer, String>> entries = tm.entrySet();
        for (Map.Entry<Integer, String> entry : entries) {
            bw.write(entry.getValue());//获取集合的值
            bw.newLine();//一行一行的写入,的分割符
            bw.flush();//刷新数据
        }
        bw.close();
    }
}