java - 搜索文件并附加到该文件

Question

我有一个程序，它根据给定的目录路径搜索文件(其中已经有一些内容)，并允许用户向该文件添加更多内容。我能够显示目录中的所有文件，但我不确定如何选择文件并向其写入更多内容。这是到目前为止我的代码:

public static void main(String [] args)
    {

    // This shows all the files on the directory path
    File dir = new File("/Users/NasimAhmed/Desktop/");
    String[] children = dir.list();
    if (children == null) 
    {
        System.out.println("does not exist or is not a directory");
    }
    else 
    {
        for (int i = 0; i < children.length; i++) 
        {
            String filename = children[i];
            System.out.println(filename);
            // write content to sample.txt that is in the directory
            out(dir, "sample.txt");
        }
    }
}

public static void out(File dir, String fileName)
{
    FileWriter writer;

    try
    {
        writer = new FileWriter(fileName);
        writer.write("Hello");
        writer.close();
    }
    catch(IOException e)
    {
        e.printStackTrace();
    }

}

Answer 1

附加到文件的示例:

public static void appendToFile(File dir, String fileName) {
    try (FileWriter writer = new FileWriter(new File(dir, fileName), true)) {
        writer.write("Hello");
    } catch(IOException e) {
        e.printStackTrace();
    }
}