1 /*
  2  * Program which:
  3  * - Prompts the user for a file name
  4  * - Reads the specified file, which is presumed to contain punctuation 
  5  *   free lyrics to a song
  6  * - Computes the frequency of occurence of each word in a file
  7  * - Displays the resulting words, along with their frequency of occurence,
  8  *   to the output stream
  9  * - Interprets commands "COUNT", "PRINT", "HELP", and "EXIT"
 10  * - Makes use of the HashMap class
 11  */
 12 package applications;
 13 
 14 import java.io.File;
 15 import java.io.FileNotFoundException;
 16 import java.util.HashMap;
 17 import java.util.Scanner;
 18 
 19 /**
 20  *
 21  * @author notebook
 22  */
 23 public class FrequencyCounter2 {
 24 
 25     /**
 26      * @param args the command line arguments
 27      */
 28     public static void main(String[] args) throws FileNotFoundException {
 29         HashMap<String, Integer> counter = establishFrequencyCounter();
 30         dump(counter);
 31         interpret(counter);
 32 
 33     }
 34 
 35     private static HashMap<String, Integer> establishFrequencyCounter() throws FileNotFoundException {
 36         Scanner scanner = equateScannerWithFile();
 37         HashMap<String, Integer> counter = new HashMap<>();
 38         while (scanner.hasNext()) {
 39             String key = scanner.next().toLowerCase();
 40             if (counter.containsKey(key)) {
 41                 counter.replace(key, counter.get(key), counter.get(key) + 1);
 42             } else {
 43                 counter.put(key, 1);
 44             }
 45         }
 46         return counter;
 47     }
 48 
 49     private static void dump(HashMap<String, Integer> counter) {
 50         System.out.println("--- Begin contents of the hash map ...");
 51         for (String key : counter.keySet()) {
 52             System.out.println("<" + key + ":" + counter.get(key) + ">");
 53         }
 54         System.out.println("--- End contents of the hash map ...");
 55     }
 56 
 57     private static void interpret(HashMap<String, Integer> counter) {
 58         Scanner scanner = new Scanner(System.in);
 59         while (true) {
 60             System.out.print(">>> ");
 61             String command = scanner.nextLine();
 62             if (command.equalsIgnoreCase("count")) {
 63                 interpretCount(scanner, counter);
 64             } else if (command.equalsIgnoreCase("print")) {
 65                 interpretPrint(counter);
 66             } else if (command.equalsIgnoreCase("exit")) {
 67                 break;
 68             } else if (command.equalsIgnoreCase("help")) {
 69                 interpretHelp();
 70             } else {
 71                 System.out.println(
 72                         "Sorry, the command you entered is not available. "
 73                         + "You can use the \"HELP\" command to see all commands available.");
 74             }
 75         }
 76     }
 77 
 78     private static Scanner equateScannerWithFile() throws FileNotFoundException {
 79         System.out.print("Enter file name here: ");
 80         Scanner s = new Scanner(System.in);
 81         String fileName = s.nextLine();
 82         String FullFileName = createFullFileName(fileName);
 83         return new Scanner(new File(FullFileName));
 84     }
 85 
 86     private static String createFullFileName(String fileName) {
 87         String separator = System.getProperty("file.separator");
 88         String home = System.getProperty("user.home");
 89         String path = home + separator + "Documents" + separator + "NetBeansProjects" + separator;
 90         String fullFileName = path + fileName;
 91         return fullFileName;
 92     }
 93 
 94     private static void interpretCount(Scanner scanner, HashMap<String, Integer> counter) {
 95         System.out.print("word?  ");
 96         String word = scanner.nextLine().toLowerCase();
 97         if (counter.containsKey(word)) {
 98             System.out.println(counter.get(word));
 99         } else {
100             System.out.println(word + " is not in the hash map.");
101         }
102     }
103 
104     private static void interpretPrint(HashMap<String, Integer> counter) {
105         for (String key : counter.keySet()) {
106             System.out.println("<" + key + ":" + counter.get(key) + ">");
107         }
108     }
109 
110     private static void interpretHelp() {
111         System.out.println("COUNT -- Give the frequency of occurrence of the word entered");
112         System.out.println("PRINT -- Display the hash map");
113         System.out.println("EXIT -- Exit the program");
114         System.out.println("HELP -- Display all available commands");
115     }
116 
117 }
118