public String map() {
   Department department = new Department();
   department.setName("aaa");
   department.setDescription("bbb");
   Map<String, Department> map = new HashMap<String, Department>();
   map.put("d1", department);
   ActionContext.getContext().put("map", map);
   return "list";
 }
  public String listMap() {
    List<Map<String, Department>> list = new ArrayList<>();

    Department department = new Department();
    department.setName("aaa");
    department.setDescription("bbb");
    Map<String, Department> map = new HashMap<String, Department>();
    map.put("d1", department);
    list.add(map);
    ActionContext.getContext().put("list", list);
    return "list";
  }
  public String mapList() {
    Map<String, List<Department>> map = new HashMap<>();
    Department department = new Department();
    department.setName("aaa");
    department.setDescription("bbb");
    List<Department> departments = new ArrayList<>();
    departments.add(department);

    Department department2 = department = new Department();
    department2.setName("ccc");
    department2.setDescription("ddd");
    departments.add(department);

    map.put("list", departments);

    ActionContext.getContext().put("map", map);
    return "list";
  }