在jsp中遍历嵌套的哈希图

Question

我写了一个嵌套的hashmap，如下。。。

    HashMap<String, String> choice_map = new HashMap<String, String> ();
    choice_map.put("4","<?php ?>");
    choice_map.put("2","<? ?>");
    choice_map.put("1","<? >");
    choice_map.put("3","< ?>");
    HashMap<String, String> que_id_map = new HashMap<String, String> ();
    que_id_map.put("1",null);
    HashMap<String, String> que_type_map = new HashMap<String, String> ();
    que_type_map.put("Objective",null);
    HashMap<String, String> que_map = new HashMap<String, String> ();
    que_map.put("What is Short Tag in PHP?",null);
    HashMap<String, HashMap<String, String>> main_choice_map = new HashMap<String, HashMap<String, String>>();

    main_choice_map.put("question",que_map);
    main_choice_map.put("question_type_id",que_id_map);
    main_choice_map.put("question_type",que_type_map);
    main_choice_map.put("choices",choice_map);
   HashMap<String, HashMap<String, HashMap<String, String>>> questions_with_choices = new HashMap<String, HashMap<String, HashMap<String, String>>> ();
   questions_with_choices.put("2",main_choice_map);

上面的hashmap（questions_with_choices）的输出如下：

｛2=｛question_type_id＝｛1=null｝，question_type＝{Objective=null｝

如何在jsp或jstl中迭代这个hashmap？

请帮帮我。

Answer 1

<%
Iterator it = mp.entrySet().iterator();
while (it.hasNext()) {
    Map.Entry pairs = (Map.Entry)it.next();
%>
    <h1><%=pairs.getKey()%> = <%=pairs.getValue()%></h1>
<%
    it.remove(); // avoids a ConcurrentModificationException
}
%>