Iterator 设计模式

Iterator模式：可以为容器或其子容器实现不同的迭代方法或多个迭代方法。

 

package com;

import java.util.Iterator;

public class Book{
 private String bookName;
 private String author;
 public String getBookName() {
  return bookName;
 }
 public void setBookName(String bookName) {
  this.bookName = bookName;
 }
 public String getAuthor() {
  return author;
 }
 public void setAuthor(String author) {
  this.author = author;
 }
}

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class BookBox implements Iterable{
 private List bookBox=new ArrayList();

 public Iterator iterator() {
  return new BookIterator();
 }
 
 public void add(Book book){
  bookBox.add(book);
 }
 private  class BookIterator implements Iterator{
  private int index;
  
  public boolean hasNext() {
   if(index<bookBox.size()){
    return true;
   }
   else{
    return false;
   }
  }

  public Object next() {
   return bookBox.get(index++);
  }

  public void remove() {
   
  }
  
 }
}

public class Test {

 public static void main(String[] args) {
  BookBox box=new BookBox();
  
  Book b1=new Book();
  b1.setBookName("book one");
  Book b2=new Book();
  b2.setBookName("book two");
  Book b3=new Book();
  b3.setBookName("book three");
  Book b4=new Book();
  b4.setBookName("book foure");
  
  box.add(b1);
  box.add(b2);
  box.add(b3);
  box.add(b4);
  
  Iterator it=box.iterator();
  while(it.hasNext()){
   Book b=(Book)it.next();
   System.out.println("BookName: "+b.getBookName());
  }
 }

}