JQuery回调没有执行？

Question

I want to have a progressbar that take data from server, so I created 2 servlets the first one ( process ) starts the process and when it ends return the result; 我想有一个从服务器获取数据的进度条，所以我创建了2个servlet，第一个（ process ）启动进程，结束时返回结果; the second one ( GetEvent ) gets progress information from session every 500ms.. 第二个（ GetEvent ）每500ms从会话中获取进度信息..

All of this works normally and the progress information is displayed correctly, but the process Servlet's callback never executes. 所有这些都正常工作，并且正确显示了进度信息，但进程Servlet的回调从不执行。

 <html>
    <head>
      <link href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/base/jquery-ui.css" rel="stylesheet" type="text/css"/>
      <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.5/jquery.min.js"></script>
      <script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js"></script>

      <script>
      $(document).ready(function() {
      process();
     $("#progressbar").progressbar({ value: 0 });
         $("#progressStatus").html("");

        getEvent();
      });
      function process()
      {
       $.getJSON("process", function(result){
         //never executed
         alert( "Result: " );

       });
      }
      function getEvent()
      {
        $.getJSON("GetProgressEvent", function(data) {     
        $.each(data.ProgressEvents, function(){
        $("#progressbar").progressbar({ value: this.progress });
         $("#progressStatus").html(this.status);
        });
        });
           setTimeout(getEvent, 500);
      }
      </script>
    </head>
    <body style="font-size:62.5%;">

    <div id="progressbar"></div>
    <div id ="progressStatus"></div>
    </body>
    </html>

I just started with JQuery and I don't know what's wrong with this code. 我刚开始使用JQuery，我不知道这段代码有什么问题。

Answer 1

you are calling $.getJSON with a url "process" this function has no error handling if there is problem with the response or invalid JSON is returned then the callback will not be called. 你正在使用url“process”调用$ .getJSON这个函数没有错误处理，如果响应有问题或者返回了无效的JSON，那么将不会调用回调。

http://api.jquery.com/jQuery.getJSON/ http://api.jquery.com/jQuery.getJSON/

jQuery.getJSON( url, [data], [success(data, textStatus, jqXHR)] ) jQuery.getJSON（url，[data]，[success（data，textStatus，jqXHR）]）

url A string containing the URL to which the request is sent. url包含发送请求的URL的字符串。

data A map or string that is sent to the server with the request. data与请求一起发送到服务器的映射或字符串。

success(data, textStatus, jqXHR)A callback function that is executed if the request succeeds. success（data，textStatus，jqXHR）如果请求成功则执行的回调函数。

Try adding a valid url in place of "process" and if that fails use the $.ajax method as follows 尝试添加有效的URL代替“进程”，如果失败则使用$ .ajax方法，如下所示

$.ajax({
  url: "mydomain.com/url",
  type: "POST",
  dataType: "json",
  data: $.param( $("Element or Expression") ),

  complete: function() {
    //called when complete
  },

  success: function() {
    //called when successful
 },

  error: function() {
    //called when there is an error
  },
});

JQuery回调没有执行？

问题描述

1 个解决方案

解决方案1
2 已采纳 2011-08-25 15:51:17

JQuery回调没有执行？

问题描述

1 个解决方案

解决方案1 2 已采纳 2011-08-25 15:51:17

解决方案1
2 已采纳 2011-08-25 15:51:17