创建一个与a.txt文件同目录下的另一个文件b.txt

File file1 = new("d:\\a\\a.txt");
File file2 = new(file1.getParent(),"b.txt")；

　　

File file1 = new("d:\\a\\a.txt");
File file2 = new(file1.getParent(),"b.txt")；