1.前台页面：

    function sayHello() {
            var userName=dojo.byId("userName").value;
            dojo.xhrGet({
                url: "<%=request.getContextPath()%>/test.do?method=test",
                handleAs: "text",
                content: { key1:userName, key2: "value2", key3: "value3" },
                load: function(responseText)
                {
                  dojo.byId("first_name").value = responseText;
                  dojo.byId("t1").value = responseText;
                  dijit.byId("description").value = responseText;
                  document.getElementById("middle_initial").value=responseText;
                },
                error: function(response)
                {
                  alert("Error");
                }
            });
        }

2.后台action中：

    public ActionForward test(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html");
        response.setCharacterEncoding("utf-8");
        PrintWriter out = response.getWriter();
        String key1=request.getParameter("key1");
        out.print(key1);
        return null;
    }