逐行写入文件

Question

So my input file has some sentences, and i want to reverse the words in each sentence and keep the same order of sentences. I then need to print to a file. my problem is that my output file is only printing my last sentence, reversed.

import java.util.*;
import java.io.*; 


 public class Reverser {   //constructor   Scanner sc = null ;   public
 Reverser(File file)throws FileNotFoundException, IOException {
     sc = new Scanner (file);   }

      public void reverseLines(File outpr)throws FileNotFoundException, IOExeption{

     //PrintWriter pw = new PrintWriter(outpr);
     while(sc.hasNextLine()){
       String sentence = sc.nextLine();
       String[] words = sentence.split(" ");
       ArrayList<String> wordsarraylist = new ArrayList<String>(Arrays.asList(words));
       Collections.reverse(wordsarraylist);



      FileWriter fw = new FileWriter(outpr); 
      BufferedWriter bw = new BufferedWriter(fw);

      for(String str: wordsarraylist) {
         bw.write(str + " ");


        bw.newLine();
        bw.close();
      }

     }   }
       }

Answer 1

That's because each time you loop, you reopen the file in overwrite mode.

Open the file before you start looping instead.

Don't use the append option here, it'll just make you open/close the file needlessly.