無法通過AJAX將JSON對象從Javascript發佈到Servlet

Question

我想通過AJAX將JSON對象發佈到servlet。但是，該對象在servlet中爲null。我無法弄清楚這段代碼有什麼問題。

JAVASCRIPT

function submitValues(event, val1, val2) 
{  
var xmlHttpObj = new XMLHttpRequest();     
      if(window.XMLHttpRequest) 
      { 
       xmlHttpObj = new XMLHttpRequest();      
      } 
      else if(window.ActiveXObject) 
      { 
       xmlHttpObj = new ActiveXObject("Microsoft.XMLHttp"); 

      } 


    var jsonObject = submitTheValues(event, val1, val2); 
     alert("json is:" +jsonObject); 
    var json = JSON.stringify(jsonObject); 
     alert("json after stringify:" +json); 

     xmlHttpObj.open("POST", "../myapp/myservlet", true); 
     xmlHttpObj.setRequestHeader("Content-type", "application/json");      
     xmlHttpObj.send(json); 

} 

SERVLET

String jsonObj = request.getParameter("json"); 

Answer 1

如果要接收數據，你就必須把它作爲發送一個application/x-www-form-urlencode參數。

xmlHttpObj.open("POST", "../myapp/myservlet", true); 
xmlHttpObj.setRequestHeader("Content-type", "application/x-www-form-urlencode");      
xmlHttpObj.send('json='+encodeURIComponent(json));