[DesignPattern] Iterator pattern

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[DesignPattern] Iterator pattern

태하팍 2014. 1. 6. 17:41

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

저작자표시 비영리 변경금지