1    package arraylistplay;
2    //program that reads a file then makes a new file that reverses the words using array lists
3    import java.io.File;
4    import java.io.FileNotFoundException;
5    import java.io.IOException;
6    import java.io.PrintWriter;
7    import java.util.ArrayList;
8    import java.util.Scanner;
9    
10   public class ReverseCopy {
11       public static void main(String[] args) throws FileNotFoundException,IOException{
12           String inputFileName = "TheBird.txt";
13           String outputFileName = "TheBirdReversed.txt";
14           ArrayList<String> words = readWordsFromFile(inputFileName);
15           writeWordsToFile(words, outputFileName);
16       }
17       private static ArrayList<String> readWordsFromFile(String inputFileName)
18           throws FileNotFoundException{
19           //equate a scanner with the input file
20           Scanner scanner = establishScanner(inputFileName);
21           //read the words from the file into a dynamically growing arraylist
22           ArrayList<String> words = new ArrayList<>();
23           while (scanner.hasNext()){
24               String word = scanner.next();
25               words.add(word);
26           }
27           return words;
28       }
29   
30       private static void writeWordsToFile(ArrayList<String> words, String outputFileName)
31           throws IOException{
32           //equate printer with an output file
33           PrintWriter printer = getPrintWriter(outputFileName);
34           //print the words to the file
35           for (int x = words.size() - 1; x >= 0; x=x-1){
36               printer.println(words.get(x));
37           }
38           printer.close();
39       }
40       private static Scanner establishScanner(String inputFileName)
41           throws FileNotFoundException{
42           String fullFileName = createFullFileName(inputFileName);
43           return new Scanner(new File(fullFileName));
44       }
45       private static PrintWriter getPrintWriter(String outputFileName)
46           throws FileNotFoundException{
47           String fullFileName = createFullFileName(outputFileName);
48           PrintWriter printer = new PrintWriter(fullFileName);
49           return printer;
50       }
51       //create the full file name for a simpe file name, assuming that is will be
52       //found in the CS1Files/data subdirectory of the users home directory
53       private static String createFullFileName(String fileName){
54           String separator = System.getProperty("file.separator");
55           String home = System.getProperty("user.home");
56           String path = home + separator + "CS1Files" + separator + "data" + separator;
57           String fullFileName = path + fileName;
58           return fullFileName;
59       }
60   }
61