Reversing Lines With Recursion Java

问题

I am just trying to reverse the lines which I receive from the input, but every single time I run my code, the output.txt file is empty. What am I missing? It appears mostly correct to me, even the recursion passage.

Thanks

import java.io.BufferedReader; 
import java.io.FileReader;
import java.io.FileWriter; 
import java.io.PrintWriter;

public class ReverseLines { 

  public static BufferedReader input;
  public static PrintWriter output;

  public static void main(String[] args) throws Exception{

    input = new BufferedReader(new FileReader(args[0]));
    output = new PrintWriter(new FileWriter(args[1]));
    reverse(input, output);

  }

  public static void reverse( BufferedReader input, PrintWriter output)
         throws Exception { 

    String line = input.readLine();
    if(line != null) {
    reverse (input, output);
    output.println(line);
    }    

  }

}

回答1:

Close the PrintWriter in your main method:

output.close();

回答2:

do output.flush() and check whether it works!

来源：https://stackoverflow.com/questions/15909734/reversing-lines-with-recursion-java