1    package arraylistplay;
2    
3    /* 
4    * This program features an ArrayList to do its reverse copy thing 
5    * from one file to another. 
6     */
7    
8    import java.io.File;
9    import java.io.FileNotFoundException;
10   import java.io.IOException;
11   import java.io.PrintWriter;
12   import java.util.ArrayList;
13   import java.util.Scanner;
14   
15   public class ReverseCopy {
16   
17       public static void main(String[] args) throws FileNotFoundException, IOException
18       {
19           String inputFileName = "JetBlackHeart";
20           String outputFileName = "JetBlackHeartReversed";
21           ArrayList<String> words = readWordsFromFile(inputFileName);
22           writeWordsToFile(words, outputFileName);
23       }
24   
25       private static ArrayList<String> readWordsFromFile(String inputFileName)
26           throws FileNotFoundException {
27           // Equate a scanner with the input file
28           Scanner scanner = establishScanner(inputFileName);
29           // Read the words from the file into a dynamically growing ArrayList
30           ArrayList<String> words = new ArrayList<>();
31           while(scanner.hasNext())
32           {
33               String word = scanner.next();
34               words.add(word);
35       }
36           // Return the words
37           return words;
38       }
39   
40       private static void writeWordsToFile(ArrayList<String> words, String outputFileName)
41           throws IOException {
42           // Equate a printer with an output file
43           PrintWriter printer = getPrintWriter(outputFileName);
44           // Print the words to the file
45           for(int x = words.size() - 1; x >= 0; x = x - 1)
46           {
47               printer.println(words.get(x));
48           }
49           printer.close();
50       }
51   
52       private static Scanner establishScanner(String inputFileName)
53           throws FileNotFoundException {
54           String fullFileName = createFullFileName(inputFileName);
55           return new Scanner(new File(fullFileName));
56       }
57   
58       private static PrintWriter getPrintWriter(String outputFileName)
59           throws FileNotFoundException {
60           String fullFileName = createFullFileName(outputFileName);
61           PrintWriter printer = new PrintWriter(fullFileName);
62           return printer;
63       }
64   
65       // Create the full file name for a simple file name, assuming that it will be
66       // found in the CS1Files/data subdirectory of the user's home directory.
67       private static String createFullFileName(String fileName)
68       {
69           String separator = System.getProperty("file.separator");
70           String home = System.getProperty("user.home");
71           String path = home + separator + "CS1Files" + separator + "data" + separator;
72           String fullFileName = path + fileName;
73           return fullFileName;
74       }
75   }
76