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package lab11;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Arrays;
import java.util.Set;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.Scanner;
import java.util.TreeSet;



/**
 *
 * @author For Students
 */
public class Lab11 {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
         Set<String> set = new HashSet<>();
         set.add("London");
         set.add("Paris");
         set.add("New York");
         set.add("San Francisco");
         set.add("Beijing");
         set.add("New York");
         System.out.println(set);
         
         for (String s: set) {
             System.out.print(s.toUpperCase() + " ");
         }
         
         testMethodsInCollection();
         testLinkedHashSet();
         testTreeSet();
         testCountKeywords();
    }
    
    public static void testMethodsInCollection ()
    {
        Set<String>set1 = new HashSet<>();
        set1.add("London");
        set1.add("Paris");
        set1.add("New York");
        set1.add("San Francisco");
        set1.add("Beijing");
        
        System.out.println("set1 is " + set1);
        System.out.println(set1.size() + " elements in set1");
        
        set1.remove("London");
        System.out.println("\nset1 is " + set1);
        System.out.println(set1.size() + " elements in set1");
        Set<String> set2 = new HashSet<>();
        set2.add("London");
        set2.add("Shanghai");
        set2.add("Paris");
        System.out.println("\nset2 is " + set2);
        System.out.println(set2.size() + " elements in set2");
        
        System.out.println("\nIs Taipei in set2? " + set2.contains("Taipei"));
        
        set1.addAll(set2);
        System.out.println("\nAfter adding set2 to set1, set1 is "+ set1);

        set1.removeAll(set2);
        System.out.println("After removing set2 from set1, set1 is " + set1);
        
        set1.retainAll(set2);
        System.out.println("After removing common elements in set2 " + "from set1, set1 is " + set1);

    }
    
    public static void testLinkedHashSet()
    {
       Set<String> set = new LinkedHashSet<>();
       set.add("London");
       set.add("Paris");
       set.add("New York");
       set.add("San Francisco");
       set.add("Beijing");
       set.add("New York");	
       System.out.println(set);
       
       for (String element: set) {
            System.out.print(element.toLowerCase() + " "); 
       }
 }
    
    public static void testTreeSet()
    {
        Set<String> set = new HashSet<>();
        set.add("London");
        set.add("Paris");
        set.add("New York");
        set.add("San Francisco");
        set.add("Beijing");
        set.add("New York");
        TreeSet<String> treeSet = new TreeSet<>(set);
        System.out.println("Sorted tree set: " + treeSet);
        System.out.println("first(): " + treeSet.first());
        System.out.println("last(): " + treeSet.last());
        System.out.println("headSet(\"New York\"): " +
        treeSet.headSet("New York"));
        System.out.println("tailSet(\"New York\"): " +
        treeSet.tailSet("New York"));
        System.out.println("lower(\"P\"): " + treeSet.lower("P"));
        System.out.println("higher(\"P\"): " + treeSet.higher("P"));
        System.out.println("floor(\"P\"): " + treeSet.floor("P"));
        System.out.println("ceiling(\"P\"): " + treeSet.ceiling("P"));
        System.out.println("pollFirst(): " + treeSet.pollFirst());
        System.out.println("pollLast(): " + treeSet.pollLast());
        System.out.println("New tree set: " + treeSet);
    }
    
    public static void testCountKeywords() throws FileNotFoundException
    {
        Scanner input = new Scanner(System.in);
        System.out.print("Enter a Java source file: ");
        String filename = input.nextLine();
        File file = new File(filename);
        if (file.exists()) {
            System.out.println("The number of keywords in " + filename + " is " + countKeywords(file));
        }else {
            System.out.println("File " + filename + " does not exist");
       }
    }
    
    public static int countKeywords(File file) throws FileNotFoundException
    {
        String[] keywordString = {"abstract", "assert", "boolean",
        "break", "byte", "case", "catch", "char", "class", "const",
        "continue", "default", "do", "double", "else", "enum",
        "extends", "for", "final", "finally", "float", "goto",
        "if", "implements", "import", "instanceof", "int",
        "interface", "long", "native", "new", "package", "private",
        "protected", "public", "return", "short", "static",
        "strictfp", "super", "switch", "synchronized", "this",
        "throw", "throws", "transient", "try", "void", "volatile",
        "while", "true", "false", "null"};
        
        Set<String> keywordSet = new HashSet<>(Arrays.asList(keywordString));
        int count = 0;
        Scanner input = new Scanner(file);
        while (input.hasNext()) {
            String word = input.next();
            if (keywordSet.contains(word)) {
                count++; 
            } 
         }
        return count;
    }

 }