Java 如何在jsp中检索选择标签值？
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how to retrive select tag value in jsp?
提问by Kapil
hello i am devloping new jsp web site and i want to retrieve value from drop downlist my code is given below.
你好，我正在开发新的 jsp 网站，我想从下拉列表中检索值，我的代码如下。
<tr><td>Room Name</td><td><input type="text" name="roomname"></td></tr>
<tr><td>Room Type</td><td><select id="roomtypeid" name="roomtypeid">
<option value="2L">Conference(1-25 user) </option>
<option value="1L">restricted(1-50 user) </option>
<option value="0L">interview (1-1 meeting with recording) </option>
</select>
in another page i am trying to get value of textbox like below.
在另一个页面中，我试图获取如下文本框的值。
java.lang.String name =request.getParameter("roomname");
this run perfectly but when i try to get value from dropdown. i get null value.i try following code.
这运行完美，但是当我尝试从下拉列表中获取价值时。我得到空值。我尝试以下代码。
out.println("your selection is..." + request.getParameter("roomtyperoomtypeid"));
kindly help me how to retrive value from dropdown.
请帮助我如何从下拉列表中检索值。
采纳答案by iaindownie
Should
应该
out.println("your selection is..." + request.getParameter("roomtyperoomtypeid"));
actually be:
实际上是：
out.println("your selection is..." + request.getParameter("roomtypeid"));
回答by Pradeep Simha
Change this:
改变这个：
request.getParameter("roomtyperoomtypeid"))
To:
到：
request.getParameter("roomtypeid"))
You were trying to access non-existing element, so null pointer exception.
您试图访问不存在的元素，因此空指针异常。
