四平网站建设哪家效果好软文营销案例200字
1、例子
分析：
1) 将学院看做是学校的子类，系是学院的子类，这样实际上是站在组织大小来进行分
层次的
2) 实际上我们的要求是 ：在一个页面中展示出学校的院系组成，一个学校有多个
学院，一个学院有多个系， 因此这种方案，不能很好实现的遍历的操作
3) 解决方案：=> 迭代器模式
2、基本定义
1) 迭代器模式（Iterator Pattern）是常用的设计模式，属于行为型模式
2) 如果我们的集合元素是用不同的方式实现的，有数组，还有java的集合类，
或者还有其他方式，当客户端要遍历这些集合元素的时候就要使用多种遍历
方式，而且还会暴露元素的内部结构，可以考虑使用迭代器模式解决。
3) 迭代器模式，提供一种遍历集合元素的统一接口，用一致的方法遍历集合元素，
不需要知道集合对象的底层表示，即：不暴露其内部的结构。
总结：解决元素存储类型不同
1) Iterator ： 迭代器接口，是系统提供，含义 hasNext, next, remove
2) ConcreteIterator : 具体的迭代器类，管理迭代
3) Aggregate :一个统一的聚合接口， 将客户端和具体聚合解耦
4) ConcreteAggreage:具体的聚合持有对象集合
3、代码
public class Department {private String name;private String desc;public String getName() {return name;}public void setName(String name) {this.name = name;}public String getDesc() {return desc;}public void setDesc(String desc) {this.desc = desc;}public Department(String name, String desc) {this.name = name;this.desc = desc;}
}
public interface College {public String getName();//增加系的方法public void addDepartment(String name,String desc);//返回一个迭代器，遍历public Iterator createIterator();
}
public class ComputerCollege implements College {Department[] departments;int numOfDepartment=0;//保存当前数组的对象个数public ComputerCollege() {departments=new Department[5];addDepartment("Java专业","JAVA专业");addDepartment("PHP专业","PHP专业");addDepartment("大数据专业","大数据专业");addDepartment("JS专业","JS专业");}@Overridepublic String getName() {return "计算几学院";}@Overridepublic void addDepartment(String name, String desc) {Department department=new Department(name,desc);departments[numOfDepartment]=department;numOfDepartment+=1;}@Overridepublic Iterator createIterator() {return new ComputerCollegeIterator(departments);}
}
public class ComputerCollegeIterator implements Iterator {//需要Department是以怎么样的方式存放Department[] departments;int position=0;//遍历位置public ComputerCollegeIterator(Department[] departments) {this.departments = departments;}@Overridepublic boolean hasNext() {if(position>=departments.length||departments[position]==null){return false;}else{return true;}}@Overridepublic Object next() {Department department=departments[position];position+=1;return department;}@Overridepublic void remove() {}
}public class InfoCollege implements College {List<Department> departmentList;public InfoCollege() {departmentList=new ArrayList<Department>();addDepartment("信息安全专业","信息安全专业");addDepartment("服务网络安全专业","服务网络安全专业");addDepartment("服务器安全专业","服务器安全专业");}@Overridepublic String getName() {return "信息工程学院";}@Overridepublic void addDepartment(String name, String desc) {Department department=new Department(name,desc);departmentList.add(department);}@Overridepublic Iterator createIterator() {return new InfoCollegeIterator(departmentList);}
}
public class InfoCollegeIterator implements Iterator {List<Department> departmentList;int index=-1;//索引public InfoCollegeIterator(List<Department> departmentList) {this.departmentList = departmentList;}@Overridepublic boolean hasNext() {if(index>=departmentList.size()-1){return false;}else{index+=1;return true;}}@Overridepublic Object next() {return departmentList.get(index);}@Overridepublic void remove() {}
}public class OutPutImpl {//学院集合List<College> collegeList;public void printCollege(){//从collegeList 取出所有学院Iterator<College> iterator = collegeList.iterator();while (iterator.hasNext()){//取出一个学院College college = iterator.next();System.out.println("==="+college.getName()+"=====");printDepartment(college.createIterator());}}public OutPutImpl(List<College> collegeList) {this.collegeList = collegeList;}public void printDepartment(Iterator iterator){while (iterator.hasNext()){Department d = (Department) iterator.next();System.out.println(d.getName());}}
}public class Client {public static void main(String[] args) {ArrayList<College> colleges = new ArrayList<>();ComputerCollege computerCollege = new ComputerCollege();InfoCollege infoCollege = new InfoCollege();colleges.add(computerCollege);colleges.add(infoCollege);new OutPutImpl(colleges).printCollege();}
}
总结：方法和数据 隔离