如何从数据库中填充drodown [英] How do I populate drodown from database

问题描述

我的jsp中有一个ajax get请求，在我的servlet中，doGet方法我有一个requestdistpatcher。我试图根据我的第一个下拉框填充我的第二个下拉框，数据来自数据库。在我的servlet中，我有request.setattribute到我的第二个下拉框，我不知道为什么我的第二个下拉列表没有出现我的request.setattribute数据。



这是我的代码

I have a ajax get request in my jsp, in my servlet, doGet method I have a requestdistpatcher . I am trying to populate my 2nd dropdown box based on my 1st dropdown box , data are from database. In my servlet, I have request.setattribute to my 2nd dropdown box , I am not sure why my 2nd dropdown does not appear my data from my request.setattribute.

Here are my codes

//servlet
	        
        try{
                AccountManager am = new AccountManager();

                ArrayList<string> nameList = am.retrieveName(name[0]);
                 
                request.setAttribute("name", nameList);

        	String[] name = request.getParameterValues("name");
        	
        	ArrayList<string> passwordList = am.retrievePassword(name[0]);
                 
                request.setAttribute("password", passwordList);
}
        	
        	 
        
        catch(Exception e)
        {
        	
        }

        
                RequestDispatcher requestDispatcher = request.getRequestDispatcher("/account.jsp");
	   
                 requestDispatcher.forward(request,response);

//jsp

 <select id="select1" name="select1" multiple="multiple">
				<c:foreach var="name" items="${name}" xmlns:c="#unknown">
				<option value="${name}" >${name}</option>
		    </c:foreach>     
			</select>

   <select id="select2" name="select2" multiple="multiple">
				<c:foreach var="password" items="${password}" xmlns:c="#unknown">
				<option value="${password}" >${password}</option>
		    </c:foreach>     
			</select>


$('#select2').change(function(event){
  
  $.ajax({
    url:"AccountServlet",
    type:"json",
    method: "get",
    data: $('#select1').val
   });
});</string></string>

推荐答案

{name}xmlns：c =＃unknown>
< option value =

{name}" xmlns:c="#unknown"> <option value="

{name}>

{name}" >

{name}< / option>
< / c：foreach>
< / select>

< select id =select2name =select2multiple =multiple>
< c：foreach var =passworditems =

{name}</option> </c:foreach> </select> <select id="select2" name="select2" multiple="multiple"> <c:foreach var="password" items="

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