从命令行中传递的文件名中获取文件（String [] args）

Question

so I'm having an issue reading a file that is passed into my program through the command line. So, my program is called printFile. I do the following:

java printFile text1.txt

In my main, I have:

try{
 Scanner scan=new Scanner(args[0]);
  while(scan.hasNextLine())
  {
  System.out.println(scan.nextLine());
  }
 }
 catch(IOException e)
 {
 e.printStackTrace();
 }

How can I correctly get the file passed in through the command line?

Answer 1

Scanner(String) creates a scanner from the specified string. But you want to scan the content of a file, so you want to use the Scanner(File) constructor.

Change from this:

 Scanner scan=new Scanner(args[0]); 

To this:

 Scanner scan = new Scanner(new File(args[0]));