如何使用一个ajax请求从Javaservlet返回多个json对象

我正在使用jsp和servlet构建web应用程序，我从jsp发送ajax请求，我想从servlet返回两个json对象。我尝试执行以下操作，但代码不起作用

//在jquery中，我编写了以下代码

        var id = $(this).attr('id');

        var paramenters = {"param":id};

        $.getJSON("MyServlet", paramenters, function (data1,data2){

            $("h3#name").text(data1["name"]);

            $("span#level").text(data1["level"]);

            $("span#college").text(data2["college"]);

            $("span#department").text(data2["department"]);

        });

    String json1 = new Gson().toJson(object1);

    String json2 = new Gson().toJson(object2);

    response.setContentType("application/json");

    response.setCharacterEncoding("utf-8");

    response.getWriter().write(json1);

    response.getWriter().write(json2);

//在servlet中，我编写了以下代码

        var id = $(this).attr('id');

        var paramenters = {"param":id};

        $.getJSON("MyServlet", paramenters, function (data1,data2){

            $("h3#name").text(data1["name"]);

            $("span#level").text(data1["level"]);

            $("span#college").text(data2["college"]);

            $("span#department").text(data2["department"]);

        });

    String json1 = new Gson().toJson(object1);

    String json2 = new Gson().toJson(object2);

    response.setContentType("application/json");

    response.setCharacterEncoding("utf-8");

    response.getWriter().write(json1);

    response.getWriter().write(json2);

---

有人能帮我吗？

将它们包装在JSON数组中：

[ {..}, {..}, {..}]

或者，将它们包装到另一个对象中：

{ "result1":{..}, "result2":{..} }

---

您可以返回一个JSON数组，其中两个对象都是数组的元素。让servlet返回具有如下结构的JSON：

[{"name": "object1"}, {"name": "object2"}]

然后，您的javascript代码可以如下所示：

$.getJSON("MyServlet", paramenters, function (data){
        var data1 = data[0];
        var data2 = data[1];

        $("h3#name").text(data1["name"]);

        $("span#level").text(data1["level"]);

        $("span#college").text(data2["college"]);

        $("span#department").text(data2["department"]);

    });

protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    ...
    resp.setContentType("application/json");
    resp.setCharacterEncoding("utf-8");
    ArrayList<Object> obj_arr = new ArrayList<Object>();
    obj_arr.add(obj1);
    obj_arr.add(obj2);
    Gson gson = new Gson();
    String tmp = gson.toJson(obj_arr);
    resp.getWriter().write(tmp);
}

---

您需要将这两个字符串放入一个json字符串中，如下所示

response.getWriter().write("[");
response.getWriter().write(json1);
response.getWriter().write(",");
response.getWriter().write(json2);
response.getWriter().write("]");

这将它们放入一个json数组中

您还可以将它们放在json对象中

response.getWriter().write("{\"object1\":");
response.getWriter().write(json1);
response.getWriter().write(",\"object2\":");
response.getWriter().write(json2);
response.getWriter().write("}");

---

你应该这样做：

$.getJSON("MyServlet", paramenters, function (data){
        var data1 = data[0];
        var data2 = data[1];

        $("h3#name").text(data1["name"]);

        $("span#level").text(data1["level"]);

        $("span#college").text(data2["college"]);

        $("span#department").text(data2["department"]);

    });

protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    ...
    resp.setContentType("application/json");
    resp.setCharacterEncoding("utf-8");
    ArrayList<Object> obj_arr = new ArrayList<Object>();
    obj_arr.add(obj1);
    obj_arr.add(obj2);
    Gson gson = new Gson();
    String tmp = gson.toJson(obj_arr);
    resp.getWriter().write(tmp);
}

服务器端：

String json1 = new Gson().toJson(object1); 
String json2 = new Gson().toJson(object2); 
response.setContentType("application/json"); 
response.setCharacterEncoding("utf-8"); 
String bothJson = "["+json1+","+json2+"]"; //Put both objects in an array of 2 elements
response.getWriter().write(bothJson);

客户端：

$.getJSON("MyServlet", paramenters, function (data){ 
   var data1=data[0], data2=data[1]; //We get both data1 and data2 from the array
   $("h3#name").text(data1["name"]); 
   $("span#level").text(data1["level"]); 
   $("span#college").text(data2["college"]); 
   $("span#department").text(data2["department"]);
});

---

希望这有帮助。干杯

@埃德加的回答对我很有用。但是我认为我们应该避免自己形成数组，所以我建议使用列表。代码如下所示：

$.getJSON("MyServlet", paramenters, function (data){
        var data1 = data[0];
        var data2 = data[1];

        $("h3#name").text(data1["name"]);

        $("span#level").text(data1["level"]);

        $("span#college").text(data2["college"]);

        $("span#department").text(data2["department"]);

    });

protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    ...
    resp.setContentType("application/json");
    resp.setCharacterEncoding("utf-8");
    ArrayList<Object> obj_arr = new ArrayList<Object>();
    obj_arr.add(obj1);
    obj_arr.add(obj2);
    Gson gson = new Gson();
    String tmp = gson.toJson(obj_arr);
    resp.getWriter().write(tmp);
}