1    /* 
2    *Program featuring an arrayList to store and interactively manipulate a list of Words. 
3     */
4    
5    package arraylistplay;
6    
7    import javax.print.attribute.SetOfIntegerSyntax;
8    import java.io.File;
9    import java.io.FileNotFoundException;
10   import java.util.ArrayList;
11   import java.util.Scanner;
12   
13   public class WordList {
14   
15       //Variables local to the class, and hence global to the methods
16      private static ArrayList<String>Words= new ArrayList<>();
17       private static Scanner commandReader= new Scanner(System.in);
18   
19       public static void main(String[]args) {
20           try {
21   
22               //Establish the array of numbers
23               readWords();
24               //Check the data
25               System.out.println("\nThe original list of numbers...");
26               displayWords();
27               //Enter the interpreter
28               interpreter();
29           } catch (FileNotFoundException ex) {
30               System.out.println("The file was not found. Please think again.");
31               System.exit(-1);
32   
33           }
34       }
35       private static void readWords() throws FileNotFoundException {
36           Scanner scanner = establishScanner("WordSet.txt");
37           while (scanner.hasNext()) {
38               Words.add(scanner.next());
39           }
40       }
41       private static Scanner establishScanner (String fn) throws FileNotFoundException {
42           String separator = File.separator;
43           String homeDirectory = System.getProperty("user.home");
44           String path = homeDirectory + separator + "public_html" + separator + "data" + separator;
45           String fullFileName = path + fn;
46           return new Scanner(new File(fullFileName));
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               interpretPrintCommand();
55           } else if (command.equalsIgnoreCase("SWAP")) {
56               interpretSwapCommand();
57           } else if (command.equalsIgnoreCase("ADD")) {
58               interpretAddCommand();
59           } else if (command.equalsIgnoreCase("HELP")) {
60               interpretHelpCommand();
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 interpreterDisplayCommand() {
70           displayWords();
71       }
72   
73       private static void displayWords() {
74           for (int x = 0; x< Words.size(); x=x+1){
75               System.out.println(Words.get(x));
76           }
77       }
78       private static void interpretPrintCommand() {
79           String operand= commandReader.next();
80           if (operand.equalsIgnoreCase("FIRST")) {
81               System.out.println(Words.get(0));
82           }else if (operand.equalsIgnoreCase("LAST")) {
83               System.out.println(Words.get(Words.size()-1));
84           }else {
85               int index= Integer.valueOf(operand);
86               System.out.println(Words.get(index-1));
87           }
88       }
89       private static void interpretSwapCommand() {
90           int position1= commandReader.nextInt();
91           int position2= commandReader.nextInt();
92           String temp= Words.get(position1-1);
93           Words.set(position1-1, Words.get(position2-1));
94           //Words[position1-1]= Words[position2-1];// changing this statement to set(position2-1, temp)
95           Words.set(position2-1, temp);
96       }
97       private static void interpretHelpCommand() {
98           System.out.println("HELP - display a menu of commands");
99           System.out.println("DISPLAY - display the list of numbers");
100          System.out.println("PRINT- print a number(FIRST; LAST; nth) ");
101          System.out.println("ADD  - add a number to the list(FIRST; LAST)");
102          System.out.println("EXIT - terminate execution of the program");
103      }
104      private static void interpretAddCommand() {
105          String position= commandReader.next();
106          if (position.equalsIgnoreCase("LAST")) {
107              addLast();
108          }else if (position.equalsIgnoreCase("FIRST")) {
109              addFIRST();
110          }else {
111              System.out.println("### invalid operand for add command");
112          }
113  
114      }
115      private static void addLast() {
116          Words.add(commandReader.next());
117      }
118      private static void addFIRST(){
119          Words.add(0,commandReader.next());
120  
121          }
122  
123      }
124  
125  
126