javascript - 如何使用ajax传递单个参数并获取多个值？

Question

这个问题已经有答案了:

What is the JSON format? [closed] (6 个回答)

已关闭 6 年前。

在我的java项目中，我使用jsp页面。这里我只传递一个参数，我想从数据库中检索多个(3)值。我知道如何仅传递和获取单个参数。但我不知道如何通过传递单个参数来获取多个值。我的ajax代码如下:

var request;
function sendInfo1() {
    var v = document.Example.wayid.value;
    // var url = 'Showroutelink.jsp?val='+v+'&start='+v1+'&end='+v2;
    var url = 'Showroutelink.jsp?val='+v;

    if (window.XMLHttpRequest) {

        request = new XMLHttpRequest();
    } else if (window.ActiveXObject) {
        request = new ActiveXObject("Microsoft.XMLHTTP");
    }

    try {

        request.onreadystatechange = getInfo1;
        request.open("GET", url, true);
        request.send();

    } catch (e) {
        alert("Unable to connect to server");
    }
}

function getInfo1() {

    if (request.readyState == 4) {
          var val = request.responseText.split('|');



        document.getElementById("start").innerHTML = val[0];
        document.getElementById("end").innerHTML = val[1];
        document.getElementById("waypoints").innerHTML = val[2];
    }
}




This is My Setver side Java code

<%
    String R_Name=request.getParameter("val");
    int w_id=0;


            String wplist = "";
            // String R_Name = request.getParameter("way");

            try {

                String buffer = "<select name='state'>";
                Class.forName("com.mysql.jdbc.Driver");
                java.sql.Connection con = DriverManager.getConnection("jdbc:mysql://localhost/googlemap", "root",
                        "root");
                Statement st = con.createStatement();

                ResultSet rs = st.executeQuery("select start from route where Route_Name='" + R_Name + "'");

                while (rs.next()) {
                    String Startval = rs.getString("start");

                    buffer = buffer + "<option value='" + Startval + "'>" + Startval + "</option>";


                }
                buffer = buffer + "</select>";
                response.getWriter().println(buffer);

            } catch (Exception e) {

            }




             try {

                String buffer1 = "<select name='state'>";
                Class.forName("com.mysql.jdbc.Driver");
                java.sql.Connection con = DriverManager.getConnection("jdbc:mysql://localhost/googlemap", "root",
                        "root");
                Statement st = con.createStatement();

                ResultSet rs = st.executeQuery("select end from route where Route_Name='" + R_Name + "'");

                while (rs.next()) {

                    String Endval = rs.getString("end");

                    buffer1 = buffer1 + "<option value='" + Endval + "'>" + Endval + "</option>";

                }
                buffer1 = buffer1 + "</select>";
                response.getWriter().println(buffer1);
            } catch (Exception e) {

            }




            try {

                String buffer2 = "<select name='state'>";
                Class.forName("com.mysql.jdbc.Driver");
                java.sql.Connection con1 = DriverManager.getConnection("jdbc:mysql://localhost/googlemap", "root",
                        "root");
                Statement st1 = con1.createStatement();

                ResultSet rs1 = st1.executeQuery("select wplist from route where Route_Name='" + R_Name + "'");
                while (rs1.next()) {
                    wplist = rs1.getString("wplist");

                    String wplist1[] = wplist.split("/");
                    buffer2 = buffer2 + "<option value='" + wplist1 + "'>" + wplist1 + "</option>";

                }
                buffer2 = buffer2 + "</select>";
                response.getWriter().println(buffer2);
            } catch (Exception e) {

            } 


    %>

Answer 1

如果我的问题是正确的，那么您是在问如何在请求中添加多个查询参数。

查询参数的结构如下:

Showroutelink.jsp?key_1=value_1&key_2=value_2&key_n=value_n

所以你只需遵循这个模式即可。

<小时/>

如果您询问如何从服务器调用返回多个值，请尝试使用 JSON。