<input type="hidden" name="selectedValue" value="0"/>  

将上面的一个放在您选择的标签的正下方

并在您的servlet中进行操作

put the above one in just below of your select tag

and do this in your servlet

String selectedValue = `request.getParameter("selectedValue")` 

现在将selectedValue设置到servlet请求中

在最终的jsp中创建一个JS函数

now set the selectedValue into the servlet request

create a JS function in your final jsp

function selectedValue(){  

    var value =<%=request.getParameter("selectedValue")%>;  
    if(value !=null)  
        {

        document.f1.slvalue.selectedIndex=value ;          

        }    

} 

在最后一个jsp页面的bodyload上调用selectedValue()函数. " slvalue "是您的选择标记的名称
参考:如何保持Dropdownlist的值相同刷新页面后 [

call the selectedValue() function on bodyload of your final jsp page. "slvalue" is a name of your select tag
Ref.:How to keep Dropdownlist value same after refresh the page[^]