java - 为什么我的输出文件是空白的？

Question

我编写了一些代码来获取输入文件textfile.txt并将其包含的行数输出到文本文件outputtextfile.txt，但输出为空。

public static void main(String args[]) throws FileNotFoundException
{       
    String inputFileName = "textfile.txt";

    printFileStats(inputFileName);
}
public static void printFileStats(String fileName) throws FileNotFoundException
{
    String outputFileName = "outputtextfile.txt";
    File inputFile = new File(fileName);
    Scanner in = new Scanner(inputFile);
    PrintWriter out = new PrintWriter(outputFileName);

    int lines = 0;
    int words = 0;
    int letters = 0;

    while(in.hasNextLine())
    {
        lines++;
    }
    out.print(lines);
}

Answer 1

从 Scanner 实例读取输入以允许 while 循环完成

while (in.hasNextLine()) {
   in.nextLine(); // add this
   lines++;
}

另外关闭PrintWriter

out.close();