1    package arraylistplay;
2    
3    import java.io.File;
4    import java.io.FileNotFoundException;
5    import java.util.ArrayList;
6    import java.util.Scanner;
7    
8    public class WordList {
9    
10       private static final int LIMIT = 1000;
11       private static ArrayList<String> words = new ArrayList<>(LIMIT);
12       //private static String[] words = new String[LIMIT];
13       private static int numberOfWords = 0;
14       private static Scanner commandReader = new Scanner(System.in);
15   
16       public static void main(String [] args){
17           try{
18               readWords();
19               interpreter();
20           } catch (FileNotFoundException ex){
21               System.out.println("The file was not found. Please think again.");
22               System.exit(-1);
23           }
24       }
25   
26       private static Scanner establishScanner(String fn) throws FileNotFoundException{
27           String separator = File.separator;
28           String homeDirectory = System.getProperty("user.home");
29           String path = homeDirectory + separator + "public_html" + separator + "data" + separator;
30           String fullFileName = path + fn;
31           return new Scanner((new File(fullFileName)));
32       }
33   
34       private static void readWords() throws FileNotFoundException{
35           Scanner scanner = establishScanner("WordSet.txt");
36           while(scanner.hasNext()){
37               String word = scanner.next();
38               words.add(word);
39           }
40       }
41   
42       private static void displayWords(){
43           for ( String word : words){
44               System.out.println(word);
45           }
46       }
47   
48       private static void interpreter() {
49           System.out.print(">>> ");
50           String command = commandReader.next();
51           if(command.equalsIgnoreCase("DISPLAY")){
52               interpreterDisplayCommand();
53           } else if (command.equalsIgnoreCase("PRINT")){
54               interpreterPrintCommand();
55           }else if (command.equalsIgnoreCase("SWAP")){
56               interpreterSwapCommand();
57           }else if (command.equalsIgnoreCase("ADD")){
58               interpreterAddCommand();
59           }else if (command.equalsIgnoreCase("HELP")){
60               interpreterHelpCommand();
61           }else if (command.equalsIgnoreCase("EXIT")){
62               System.exit(0);
63           }else {
64               System.out.println("### Unrecognizable command: " + command);
65           }
66           interpreter();
67       }
68   
69       private static void interpreterHelpCommand() {
70           System.out.println("HELP - display a menu of commands");
71           System.out.println("DISPLAY - display the list of word");
72           System.out.println("PRINT - print a word (FIRST;LAST;nth");
73           System.out.println("SWAP - excahnge two elements (nth;mth)");
74           System.out.println("ADD - add a word to the list (FIRST;LAST");
75           System.out.println("EXIT - terminate execution of the program");
76       }
77   
78       private static void interpreterAddCommand() {
79           String position = commandReader.next();
80           if (position.equalsIgnoreCase("LAST")){
81               addLast();
82           } else if (position.equalsIgnoreCase("FIRST")){
83               addFirst();
84           } else {
85               System.out.println("### invalid operand for add command");
86           }
87           numberOfWords = numberOfWords + 1;
88       }
89   
90       private static void addFirst() {
91           words.add(0, commandReader.next());
92           //for (int x = numberOfWords; x > 0; x = x - 1){
93             //  words.set(x) = words.set(x - 1);
94           //}
95           //words.add(0) = commandReader.next();
96       }
97   
98       private static void addLast() {
99           String word = commandReader.next();
100          words.add(word);
101      }
102  
103      private static void interpreterSwapCommand() {
104          int position1 = commandReader.nextInt();
105          int position2 = commandReader.nextInt();
106          String temp = words.get(position1 - 1);
107          words.set(position1 - 1, words.get(position2-1));
108          words.set(position2 - 1, temp);
109          //words[position1 - 1] = words[position2 - 1];
110         // words[position2 - 1] = temp;
111      }
112  
113      private static void interpreterPrintCommand() {
114          String operand = commandReader.next();
115          if (operand.equalsIgnoreCase("FIRST")){
116              System.out.println(words.get(0));
117          } else if (operand.equalsIgnoreCase("LAST")){
118              System.out.println(words.get(numberOfWords - 1));
119          } else {
120              int index = Integer.valueOf(operand);
121              System.out.println(words.get(index - 1));
122          }
123      }
124  
125      private static void interpreterDisplayCommand() {
126          displayWords();
127      }
128  
129  
130  }
131  
132