java设计模式之迭代器模式，顾客永远的上帝

/**
 * 打印各班级的名单，1班老师用的是数组存储，2班老师用的是List
 */
public class BadCode {
 private String class1[] = {"java程序员思维", "java", "设计模式", "迭代器模式"};
 private List<String> class2 = Arrays.asList(class1);
 private void printAllName() {
 //打印1班的学生姓名
 System.out.println("1班学生姓名");
 for (String name : class1) {
 System.out.println(name);
 }
 System.out.println("-----------------");
 System.out.println("2班学生姓名");
 //打印2班的学生姓名
 for (String name : class2) {
 System.out.println(name);
 }
 }
 public static void main(String[] args) {
 BadCode badCode = new BadCode();
 badCode.printAllName();
 }
}

/**
 * 迭代器
 */
public interface Iterator {
 public boolean hasNext();
 public Object next();
}

//数组存储
public class NameArrayIterator implements Iterator {
 public String names[] = {"java程序员思维", "java", "设计模式", "迭代器模式"};
 private int index = 0;
 public boolean hasNext() {
 if (index < names.length) {
 return true;
 }
 return false;
 }
 public Object next() {
 if (this.hasNext()) {
 return names[index++];
 }
 return null;
 }
}

//list存储
public class NameListIterator implements Iterator {
 private List<String> arrayList;
 private int index = 0;
 public NameListIterator() {
 arrayList = new ArrayList<String>();
 arrayList.add("java程序员思维");
 arrayList.add("java");
 arrayList.add("设计模式");
 arrayList.add("迭代器模式");
 }
 public boolean hasNext() {
 if(index < arrayList.size()){
 return true;
 }
 return false;
 }
 public Object next() {
 Object object = arrayList.get(index);
 index++;
 return object;
 }
}

public class Client {
 private Iterator iterator;
 public Client(Iterator iterator) {
 this.iterator = iterator;
 }
 public void printName(){
 while (iterator.hasNext()){
 System.out.println(iterator.next().toString());
 }
 }
 public Iterator getIterator() {
 return iterator;
 }
 public void setIterator(Iterator iterator) {
 this.iterator = iterator;
 }
}

public class IteratorPatternTest {
 public static void main(String[] args) {
 NameArrayIterator nameArrayIterator = new NameArrayIterator();
 Client client = new Client(nameArrayIterator);
 System.out.println("使用数组存储" );
 client.printName();
 System.out.println("----------------------------");
 NameListIterator nameListIterator = new NameListIterator();
 client.setIterator(nameListIterator);
 System.out.println("使用List存储" );
 client.printName();
 }
}

public Iterator<E> iterator() {
 return new ArrayList.Itr();
}

public Iterator<E> iterator() {
 return this.map.keySet().iterator();
}