[DesignPattern - Iterator] sample1

Design Pattern - Iterator

1. 클래스다이어그램

2. Source

• Aggregate.java
  

  package com.dazzilove.iterator.sample1;
  
  import junit.framework.TestCase;
  
  public class BookAggregateTest extends TestCase {    
      public void testBookAggregateTest() {
          BookShelf bookShelf = new BookShelf(4);
          bookShelf.appendBook(new Book("Around the World in 80 Days."));
          bookShelf.appendBook(new Book("Bible"));
          bookShelf.appendBook(new Book("Cinderella"));
          bookShelf.appendBook(new Book("Daddy-Long-Legs"));
          
          Iterator it = bookShelf.iterator();
          
          while(it.hasNext()) {
              Book book = (Book)it.next();
              System.out.println("" + book.getName());
          }
      }
  }

• Iterator.java
  

  package com.dazzilove.iterator.sample1;
  
  public interface Iterator {
      public abstract boolean hasNext();
      public abstract Object next();
  }

• BookShelf.java
  

  package com.dazzilove.iterator.sample1;
  
  public class BookShelf implements Aggregate {
      private Book[] books;
      private int last = 0;
      
      public BookShelf(int maxSize) {
          this.books = new Book[maxSize];
      }
      
      public Book getBookAt(int index) {
          return books[index];
      }
      
      public void appendBook(Book book) {
          this.books[last] = book;
          last++;
      }
      
      public int getLength() {
          return this.last;
      }
      
      public Iterator iterator() {
          return new BookShelfIterator(this);
      }
  }

• BookShelfIterator.java
  

  package com.dazzilove.iterator.sample1;
  
  public class BookShelfIterator implements Iterator {
      
      private BookShelf bookShelf;
      private int index;
      
      public BookShelfIterator(BookShelf bookShelf) {
          this.bookShelf = bookShelf;
          this.index = 0;
      }
  
      @Override
      public boolean hasNext() {
          if(index < bookShelf.getLength()) {
              return true;
          } else {
              return false;
          }
      }
  
      @Override
      public Object next() {
          Book book = bookShelf.getBookAt(index);
          index++;
          return book;
      }
  }

• Book.java
  

  package com.dazzilove.iterator.sample1;
  
  public class Book {
      private String name = "";
      
      public Book(String name) {
          this.name = name;
      }
      
      public String getName() {
          return name;
      }
  }

• BookAggregateTest.java
  

  package com.dazzilove.iterator.sample1;
  
  import junit.framework.TestCase;
  
  public class BookAggregateTest extends TestCase {    
      public void testBookAggregateTest() {
          BookShelf bookShelf = new BookShelf(4);
          bookShelf.appendBook(new Book("Around the World in 80 Days."));
          bookShelf.appendBook(new Book("Bible"));
          bookShelf.appendBook(new Book("Cinderella"));
          bookShelf.appendBook(new Book("Daddy-Long-Legs"));
          
          Iterator it = bookShelf.iterator();
          
          while(it.hasNext()) {
              Book book = (Book)it.next();
              System.out.println("" + book.getName());
          }
      }
  }

3. 결과출력