html中options调用servlet

 涉及到三个文件

1、jsp

<script type="text/javascript">

function filter(obj){

var value = obj.options[obj.selectedIndex].value ;

//document.form1.action = "Filter?selected=" + value ;

       //document.form1.submit();

window.open("Filter?selected=" + value);

}

</script>

<form name="form1" action="Filter">

<select id = "select" onchange="filter(this)">

<option value="String1">String1</option>

<option value="String2">String2</option>

<option value="String3">String3</option>

<option value="String4">String4</option>

</select>

</form>

2、web.xml

  <servlet>

    <description></description>

    <display-name>Filter</display-name>

    <servlet-name>Filter</servlet-name>

    <servlet-class>com.filter.Filter</servlet-class>

  </servlet>

  <servlet-mapping>

    <servlet-name>Filter</servlet-name>

    <url-pattern>/Filter</url-pattern>

  </servlet-mapping>

3、Filter.java(servlet)

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

      test(request.getParameter("selected")) ;

}

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

test(request.getParameter("selected"));

}

public void test(String selected){

System.out.println("selected:"  + selected);

}

运行jsp，得到结果selected:String3