public static void main(String[] args) throws IOException {
BufferedReader reader = new BufferedReader(new FileReader("day.txt"));
BufferedWriter writer = new BufferedWriter(new FileWriter("day.txt"));
System.out.println(reader.readLine());
}
day.txt 我在执行前写了一些话。如果我用 Writer 更改 System.out.println,它就不会为空。为什么?
最佳答案
当您执行 new FileWriter("day.txt");
将您的代码更改为
BufferedReader reader = new BufferedReader(new FileReader("day.txt"));
BufferedWriter writer = new BufferedWriter(new FileWriter("day-new.txt"));
System.out.println(reader.readLine());
关于java - 为什么这个 pojo 程序 "readline"总是返回 null?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/54435721/