將servelt中的字符串轉成json數據傳給javascript：ajax

Question

我需要以 ajax 方式提交表單。 當表單提交時，將 servlet 中的字符串轉換為 json 數據並將其傳遞給 javascript 函數，並在每個輸入字段下方的錯誤 div 標記附近分別顯示這些錯誤。

  if(firstparamtr-condition)
    {
        String firsterror = "Error first";

        response.setContentType("application/json");

        response.setHeader("Cache-Control", "no-cache");

        response.setCharacterEncoding("UTF-8");         

        response.getWriter().write(firsterror);       

    }

   if(secondparamtr-condition)
    {
        String seconderror = "Error second";

        response.setContentType("application/json");

        response.setHeader("Cache-Control", "no-cache");

        response.setCharacterEncoding("UTF-8");         

        response.getWriter().write(seconderror);       

    }

javascript代碼

 posting.done(function( responseText ) {

   alert(responseText);

//HERE I need to separate the responseText and show that errors in the div tags named 'firstEr' and 'secondEr'      

      });

Answer 1

為了將 String 轉換為 JSON，我使用GSON轉換器，示例如下：

String string = "example"; // The String which you wish to convert JsonObject convertedObject = new Gson().fromJson(string, JsonObject.class);