Question

我正在开发一个员工调度程序Java Web应用程序，员工可以指定他们将在办公室外休假，商务旅行等等的日子......我有一个简单的机制来添加/编辑/删除这些记录。但是我正在努力使用JSTL以及哪个收集器应该传递给jsp用于forEach循环。

最终我需要在jsp页面上显示一个看起来像这样的表：

October 2010
Employee Sun Mon Tue Wed Thu Fri Sat Sun Mon Tue Wed Thu ...
                              1   2   3   4   5   6   7  ...  
  Abate   *   *   *   *   *  [E]
  Adams   *   *   *   *   *          [E]     [E]
  Benson  *   *   *   *   *      [E]             [E]

如果[E]是该特定日期针对该员工的项目或事件列表

这是来自sql调用的事件的示例列表：

EVENT_ID BADGE  EVENT_TYPE_ID EVENT_TYPE_NAME  EVENT_S_DATE 
1        134311 5610          Business Travel  2010-10-08
2        101379 7646          Floating Holiday 2010-10-11
3        005396 3600          Vacation         2010-10-12
4        134311 1318          Military         2010-10-12
5        134311 0575          Sick Time        2010-10-12
6        101379 6652          Unpaid           2010-10-18
7        111243 0575          Sick Time        2010-10-29

我的第一种方法是使用嵌套的哈希映射并在当天键入它，但我很难使用JSTL引用地图中的值，因为使用数字键的问题（我的键是在开始日偏移的单元格号），10月从第5天或周五开始。）

EL access a map value by Integer key

JSTL and hashmap not working

我预见我会在servlet中创建一堆循环来填充某种类型的容器来完成此任务。

我正在寻找至少类似“哦，在地图中嵌入一个列表并将其放入另一个地图中”的内容，以便让我开始。

Answer 1

只需更改您的DAO方法即可返回Map<Long, Event>而不是Map<Integer, Event>。

Answer 2

好的，我终于想出了嵌套的集合并自行循环，所以我会回答我自己的问题。 servlet和视图代码可能都可以使用一些改进，但它可以工作。

的Servlet

ArrayList eventListPerDayPerBadge = new ArrayList();
ArrayList eventListPerDay = new ArrayList();
HashMap eventMapByDay = new HashMap();
HashMap eventMapByDayByBadge = new HashMap();

int lastDay = 0;
int eventDay = 1;
String lastBadge = "0";
String currentBadge = "currentBadge";
Event event = null;

Iterator eventList = employeeEvents.iterator();
while (eventList.hasNext()) {

    event = (Event) eventList.next();
    eventDay = DateUtil.toCalendar(event.getEvent_s_date()).get(Calendar.DATE);

    currentBadge = event.getBadge();

    if (eventDay == lastDay) {
        eventListPerDay.add(event);
        if (currentBadge.equals(lastBadge)) {
            eventListPerDayPerBadge.add(event);
        }
        else {
            HashMap tempMap = new HashMap();
            if (eventMapByDayByBadge.get(lastBadge) != null) {
                tempMap = (HashMap) eventMapByDayByBadge.get(lastBadge);
            }
            tempMap.put(new Long(eventDay), eventListPerDayPerBadge);
            eventMapByDayByBadge.put(lastBadge, tempMap);
            eventListPerDayPerBadge = new ArrayList();
            eventListPerDayPerBadge.add(event);
        }
        eventMapByDay.put(new Long(eventDay), eventListPerDay);
    }
    else {
        if (!"0".equals(lastBadge)) {
            HashMap tempMap = new HashMap();

            if (eventMapByDayByBadge.get(lastBadge) != null) {
                tempMap = (HashMap) eventMapByDayByBadge.get(lastBadge);
            }
            tempMap.put(new Long(lastDay), eventListPerDayPerBadge);
            eventMapByDayByBadge.put(lastBadge, tempMap);
            eventMapByDay.put(new Long(lastDay), eventListPerDay);
        }

        eventListPerDayPerBadge = new ArrayList();
        eventListPerDayPerBadge.add(event);

        eventListPerDay = new ArrayList();
        eventListPerDay.add (event);

    }

    lastDay = eventDay;
    lastBadge = currentBadge;
}


// Get the last record into the maps    
HashMap tempMap = new HashMap();
if (eventMapByDayByBadge.get(lastBadge) != null) {
    tempMap = (HashMap) eventMapByDayByBadge.get(lastBadge);
}
tempMap.put(new Long(eventDay), eventListPerDayPerBadge);
eventMapByDayByBadge.put(lastBadge, tempMap);
eventMapByDay.put(new Long(eventDay), eventListPerDay);

request.setAttribute("eventMapByDayByBadge", eventMapByDayByBadge);
request.setAttribute("eventMapByDay", eventMapByDay);

视图（并非视图中使用的所有属性都显示在servlet中）：

<table align="center" border="1" cellpadding="3" cellspacing="0" width="100%">
  <tbody>
  <!-- Header ROW -->
     <tr>
        <th>Employee</th>
        <c:forEach var="week" begin="1" end="${iTotalweeks}" varStatus="status">
        <th class="optionYellow">Sun</th>
        <th>Mon</th>
        <th>Tue</th>
        <th>Wed</th>
        <th>Thu</th>
        <th>Fri</th>
        <th class="optionYellow">Sat</th>
        </c:forEach>
     </tr>
  <!-- Week Day Number ROW -->
     <tr>
        <td align="center" height="35" class="dsb">*&nbsp;</td>
        <c:forEach var="week" begin="1" end="${iTotalweeks}" varStatus="status">

           <c:forEach var="cell" begin="${1+7*(week-1)}" end="${7+7*(week-1)}"
              step="1" varStatus="status">
              <c:set var="dayNo" value="${cell-weekStartDay+1}" />
                 <c:choose>
                 <c:when test="${weekStartDay>cell || (cell-weekStartDay+1)>days}">
                    <td align="center" height="35" class="<c:out value="${weekendCellMap[cell]}" />">*&nbsp;</td>
                 </c:when>
                 <c:otherwise>
                    <td class="<c:out value="${holidayColorMap[dayNo]}" />"><span class="calDayNo"> <c:out value="${dayNo}" /></span>
                       <span class="calDayName"> <c:out value="${holidayNameMap[dayNo]}" /></span>
                    </td>
                 </c:otherwise>
                 </c:choose>
           </c:forEach>

        </c:forEach>
     </tr>

  <!-- Employee ROW -->
     <c:forEach var="employee" items="${employeeList}">
     <c:set var="map" value="${eventMapByDayByBadge[employee.badge]}" />
     <tr>
        <td align="center" height="35" NOWRAP><c:out value="${employee.lname}" />, <c:out value="${employee.firstName}" /><br>
           (<c:out value="${employee.badge}" />)
        </td>
        <c:forEach var="week" begin="1" end="${iTotalweeks}" varStatus="status">

           <c:forEach var="cell" begin="${1+7*(week-1)}" end="${7+7*(week-1)}"
              step="1" varStatus="status">
              <c:set var="dayNo" value="${cell-weekStartDay+1}" />
           <c:choose>
              <c:when test="${weekStartDay>cell || (cell-weekStartDay+1)>days}">
                 <td align="center" height="35" class="<c:out value="${weekendCellMap[cell]}" />">*&nbsp;</td>
              </c:when>
              <c:otherwise>
                 <td align="center" height="35" class="<c:out value="${holidayColorMap[dayNo]}" />"><span>&nbsp;
                    <c:forEach var="event" items="${map[dayNo]}">
                       <c:out value="${event.event_type_name}" />
                    </c:forEach></span></td>
              </c:otherwise>
              </c:choose>
           </c:forEach>

        </c:forEach>
     </tr>
     </c:forEach>

  </tbody>
</table>

视图的输出示例

Sample Output

嵌套Java集合使用JSTL在日历网格中列出每人每天的项目？

2 个答案: