Hands-on brain --- identify txt files in the specified folder specified string all inclusive

Ideas: first determine whether a file, if the file you need to determine whether to change the file name contains the string "txt", contains the output. If it is a folder, then first need to determine whether the file name contains the ".txt" (because the file name may contain txt), and then use the recursive method to traverse subfolders.

Code: Method

public static void SearchAtString(File file,String str) {
        if(file.isFile()) {
            if((file.getName().indexOf(str))!=-1) {
                System.out.println(file.getAbsolutePath());
            }
        }else if(file.isDirectory()) {
            File[] files = file.listFiles();
            for(File f:files) {
                if(f.getName().indexOf(str)!=-1) {
                    System.out.println(f.getAbsolutePath());
                }
                SearchAtString(f,str);
            }
        }
    }

operation result: