[DesignPattern] Iterator pattern

Iterator Pattern

개요

예제(Java)

같이보기

참고 사항

<< 개요 >>

Iterator Pattern -  하나씩 열거하면서 처리 한다.

 

 

<< 예제(Java) >>

1. 결과 

실용주의 프로그래머 애자일 프로젝트 파워 스피치 왜 일하는가?

2. 테스트 코드 

package kr.pe.acet.iterator;   public class AggregateTest {     @org.junit.Test     public void testIterator() throws Exception {         BookShelf bookShelf = new BookShelf(4);         bookShelf.appendBook(new Book("실용주의 프로그래머"));         bookShelf.appendBook(new Book("애자일 프로젝트"));         bookShelf.appendBook(new Book("파워 스피치"));         bookShelf.appendBook(new Book("왜 일하는가?"));         Iterator it = bookShelf.iterator();         while(it.hasNext()){             Book book = (Book)it.next();             System.out.println(book.getName());         }     } }

 

3.Aggregate  

package kr.pe.acet.iterator; import java.util.Iterator; public interface Aggregate {     public abstract kr.pe.acet.iterator.Iterator iterator(); }

4. BookShelf 

package kr.pe.acet.iterator; 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 last;     }     @Override     public Iterator iterator() {         // TODO Auto-generated method stub         return new BookShelfIterator(this);     } }

 

5. BookShelfIterator 

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

 

6. Iterator 

package kr.pe.acet.iterator; public interface Iterator {     public abstract boolean hasNext();     public abstract Object next(); }

 

 

<< 같이 보기 >>

1. Visitor pattern

2. Composite pattern

3. Factory Method pattern

<< 참고 사항 >>

1.Java 언어로 배우는 디자인 패턴 입문