public class Client {
 public static void main(String[] args) {
  // TODO Auto-generated method stub
  //创建学院
  List<College> collegeList = new ArrayList<College>();
  
  ComputerCollege computerCollege = new ComputerCollege();
  InfoCollege infoCollege = new InfoCollege();
  
  collegeList.add(computerCollege);
  //collegeList.add(infoCollege);
  
  OutPutImpl outPutImpl = new OutPutImpl(collegeList);
  outPutImpl.printCollege();
 }
}
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 ");
  
 }
 
 
 @Override
 public String getName() {
  // TODO Auto-generated method stub
  return "计算机学院";
 }
 @Override
 public void addDepartment(String name, String desc) {
  // TODO Auto-generated method stub
  Department department = new Department(name, desc);
  departments[numOfDepartment] = department;
  numOfDepartment += 1;
 }
 @Override
 public Iterator createIterator() {
  // TODO Auto-generated method stub
  return new ComputerCollegeIterator(departments);
 }
}
public class ComputerCollegeIterator implements Iterator {
 //这里我们需要Department 是以怎样的方式存放=>数组
 Department[] departments;
 int position = 0; //遍历的位置
 public ComputerCollegeIterator(Department[] departments) {
  this.departments = departments;
 }
 //判断是否还有下一个元素
 @Override
 public boolean hasNext() {
  // TODO Auto-generated method stub
  if(position >= departments.length || departments[position] == null) {
   return false;
  }else {
  
   return true;
  }
 }
 @Override
 public Object next() {
  // TODO Auto-generated method stub
  Department department = departments[position];
  position += 1;
  return department;
 } 
 //删除的方法，默认空实现
 public void remove() {
  
 }
}
public class Department {
 private String name;
 private String desc;
 public Department(String name, String desc) {
  super();
  this.name = name;
  this.desc = 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 class InfoColleageIterator implements Iterator {
 
 List<Department> departmentList; // 信息工程学院是以List方式存放系
 int index = -1;//索引
 
 public InfoColleageIterator(List<Department> departmentList) {
  this.departmentList = departmentList;
 }
 //判断list中还有没有下一个元素
 @Override
 public boolean hasNext() {
  // TODO Auto-generated method stub
  if(index >= departmentList.size() - 1) {
   return false;
  } else {
   index += 1;
   return true;
  }
 }
 @Override
 public Object next() {
  // TODO Auto-generated method stub
  return departmentList.get(index);
 }
 //空实现remove
 public 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("网络安全专业", " 网络安全专业 ");
  addDepartment("服务器安全专业", " 服务器安全专业 ");
 }
 
 @Override
 public String getName() {
  // TODO Auto-generated method stub
  return "信息工程学院";
 }
 @Override
 public void addDepartment(String name, String desc) {
  // TODO Auto-generated method stub
  Department department = new Department(name, desc);
  departmentList.add(department);
 }
 @Override
 public Iterator createIterator() {
  // TODO Auto-generated method stub
  return new InfoColleageIterator(departmentList);
 }
}
public class OutPutImpl {
 
 //学院集合
 List<College> collegeList;
 public OutPutImpl(List<College> collegeList) {
  
  this.collegeList = collegeList;
 }
 //遍历所有学院,然后调用printDepartment 输出各个学院的系
 public void printCollege() {
  
  //从collegeList 取出所有学院, Java 中的 List 已经实现Iterator
  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()); //得到对应迭代器
  }
 }
 
 //输出 学院输出 系
 
 public void printDepartment(Iterator iterator) {
  while(iterator.hasNext()) {
   Department d = (Department)iterator.next();
   System.out.println(d.getName());
  }
 }
}