1    /* 
2    * This program features an ArrayList to do its reverse copy thing 
3    * from one file to another. 
4    */
5    
6    package arraylistplay;
7    import java.io.File;
8    import java.io.FileNotFoundException;
9    import java.io.IOException;
10   import java.io.PrintWriter;
11   import java.util.ArrayList;
12   import java.util.Scanner;
13   
14   public class ReverseCopy {
15   
16           public static void main(String[] args) throws FileNotFoundException, IOException {
17           String inputFileName = "YellowSubmarine.text";
18           String outputFileName = "YellowSubmarineReversed.text";
19           ArrayList<String> words = readWordsFromFile(inputFileName);
20           writeWordsToFile(words, outputFileName);
21           }
22   
23           private static ArrayList<String> readWordsFromFile(String inputFileName)
24           throws FileNotFoundException {
25           // Equate a scanner with the input file
26           Scanner scanner = establishScanner(inputFileName);
27           // Read the words from the file into a dynamically growing ArrayList
28           ArrayList<String> words = new ArrayList<>();
29           while (scanner.hasNext()) {
30               String word = scanner.next();
31               words.add(word);
32               }
33           // Return the words
34           return words;
35           }
36   
37           private static void writeWordsToFile(ArrayList<String> words, String outputFileName)
38           throws IOException {
39           // Equate a printer with an output file
40           PrintWriter printer = getPrintWriter(outputFileName);
41           // Print the words to the file
42           for (int x = words.size() - 1; x >= 0; x = x - 1) {
43               printer.println(words.get(x));
44               }
45           printer.close();
46           }
47   
48           private static Scanner establishScanner(String inputFileName)
49           throws FileNotFoundException {
50           String fullFileName = createFullFileName(inputFileName);
51           return new Scanner(new File(fullFileName));
52           }
53   
54           private static PrintWriter getPrintWriter(String outputFileName)
55           throws FileNotFoundException {
56           String fullFileName = createFullFileName(outputFileName);
57           PrintWriter printer = new PrintWriter(fullFileName);
58           return printer;
59           }
60   
61           // Create the full file name for a simple file name, assuming that it will be
62          // found in the CS1Files/data subdirectory of the user’s home directory.
63           private static String createFullFileName(String fileName) {
64           String separator = System.getProperty("file.separator");
65           String home = System.getProperty("user.home");
66           String path = home + separator + "CS1Files" + separator + "data" + separator;
67           String fullFileName = path + fileName;
68           return fullFileName;
69           }
70   
71   }
72