JAVA集合框架

package com.zking.zy;  import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.Set;  public class Zy4 {   public static void main(String[] args) {  List<Student> ls =new ArrayList<Student>();  ls.add(new Student("张晓东", 90.5));  ls.add(new Student("张晓东", 75.5));  List<Student> ls1 =new ArrayList<Student>();  ls1.add(new Student("张晓北",80.5));  ls1.add(new Student("张三", 90.5));  List<Student> ls2 =new ArrayList<Student>();  ls2.add(new Student("小八",70.5));  ls2.add(new Student("小九",100.5));  List<Student> ls3 =new ArrayList<Student>();  ls3.add(new Student("可乐", 60.5));  ls3.add(new Student("雪碧",50.5));  List<Student> ls4 =new ArrayList<Student>();  ls4.add(new Student("哇哈哈",90.5));  ls4.add(new Student("老干妈",80.5));  List<Student> ls5 =new ArrayList<Student>();  ls5.add(new Student("哇哈哈",96.5));  ls5.add(new Student("嘿嘿嘿",81.5));  Map<String,List<Student>> map = new HashMap<String,List<Student>>();  map.put("T110", ls);  map.put("T111", ls1);  Map<String,List<Student>> map1 = new HashMap<String,List<Student>>();  map1.put("T206", ls2);  map1.put("T222", ls3);  Map<String,List<Student>> map2 = new HashMap<String,List<Student>>();  map2.put("T230", ls4);  map2.put("T231", ls5);  map.put("T110", ls);  map.put("T111", ls1);  Map<String, Map<String,List<Student>>> mapa =new HashMap<String, Map<String,List<Student>>>();  mapa.put("卓京初中部", map);  mapa.put("卓京高中部", map1);  mapa.put("卓京大学部", map2);   Set<Entry<String, Map<String, List<Student>>>> entrySet2 = mapa.entrySet();   for (Entry<String, Map<String, List<Student>>> entry : entrySet2) {   System.out.println(entry);  }   } } 

效果截图