17迭代器模式

  1 public class Course {
  2     private String name;
  3 
  4     public Course(String Name){
  5         this.name = name;
  6     }
  7 
  8     public String getName() {
  9         return name;
 10     }
 11 
 12     public void setName(String Name) {
 13         this.name = name;
 14     }
 15 }
 16 
 17 public interface Iterator<E> {
 18     E next();
 19     Boolean hasNext();
 20 }
 21 
 22 public interface CourseAggregate {
 23     void add(Course coursE);
 24     void remove(Course coursE);
 25     Iterator<Course> iterator();
 26 }
 27 
 28 public class IteratorImpl<E> implements Iterator<E> {
 29 
 30     private List<E> list;
 31     private int cursor;
 32     private E element;
 33     public IteratorImpl(List list){
 34         this.list = list;
 35     }
 36 
 37     @Override
 38     public E next() {
 39         System.out.println("当前位置" + cursor + "：");
 40         element = list.get(cursor);
 41         cursor++;
 42         return element;
 43     }
 44 
 45     @Override
 46     public Boolean hasNext() {
 47         if(cursor>list.size()-1){
 48             return false;
 49         }
 50         return true;
 51     }
 52 }
 53 
 54 public class CourseAggregateImpl implements CourseAggregate {
 55 
 56     private List courseList;
 57 
 58     public CourseAggregateImpl(){
 59         this.courseList = new ArrayList();
 60     }
 61 
 62     @Override
 63     public void add(Course coursE) {
 64         courseList.add(coursE);
 65     }
 66 
 67     @Override
 68     public void remove(Course coursE) {
 69         courseList.remove(coursE);
 70     }
 71 
 72     @Override
 73     public Iterator<Course> iterator() {
 74         return new IteratorImpl<Course>(courseList);
 75     }
 76 }
 77 
 78 public class IteratorTest {
 79     public static void main(String[] args) {
 80         Course java = new Course("Java架构");
 81         Course javaBase = new Course("java入门");
 82         Course design = new Course("Java设计模式精讲");
 83         Course ai = new Course("人工智能");
 84 
 85         CourseAggregate courseAggregate = new CourseAggregateImpl();
 86         courseAggregate.add(java);
 87         courseAggregate.add(javaBasE);
 88         courseAggregate.add(design);
 89         courseAggregate.add(ai);
 90 
 91         System.out.println("------课程列表------");
 92         printCourses(courseAggregatE);
 93 
 94         courseAggregate.remove(ai);
 95 
 96         System.out.println("------删除操作之后的课程列表------");
 97         printCourses(courseAggregatE);
 98 
 99     }
100 
101     public static void printCourses(CourseAggregate courseAggregatE){
102         Iterator<Course> iterator = courseAggregate.iterator();
103         while (iterator.hasNext()){
104             Course course = iterator.next();
105             System.out.println("《" + course.getName() + "》");
106         }
107     }
108 }