ajax实现文件异步上传并回显文件相关信息功能示例

<div class="form-group">  <div class="col-sm-4">  <label class="control-label">应用文件</label></div><div class="col-sm-8">  <input type="file" name="appFile" id="appFile">  <input type="submit" value="确认上传" id="subm"></div>

$("#subm").click(function(){    var formData = new FormData();    formData.append("appFile", document.getElementById("appFile").files[0]);    alert("8888888888888888888888888");    $.ajax({      url: '${ctx}/appresources/fileUpload.shtml',      type: "POST",      data: formData,      dataType: "json",      contentType: false,      processData: false,      success: function (data) {        alert("上传成功");        $("#versionCode").val(data.versionCode);        $("#appVersion").val(data.appVersion);        $("#appPackageName").val(data.appPackageName);      },      error: function () {        alert("上传失败！");      }    });});

@ResponseBody@RequestMapping("fileUpload")public JSONObject fileUpload(MultipartFile appFile,Model model,HttpServletRequest request,HttpServletResponse response) {    ServletContext//........................省略    String infos=ApkUtil.getApkInfo(needPath+"source"+File.separator+"apk"+File.separator+fileName);    String[] info=infos.split(",");    String versionCode=info[0];//版本号    String versionName=info[1];//版本名    String packageName=info[2];//包名    String appName=fileName;    AppResourcesFormMap appResourcesFormMap = getFormMap(AppResourcesFormMap.class);    appResourcesFormMap.put("appName",fileName);    appResourcesFormMap.put("appVersion",versionName);    appResourcesFormMap.put("appPackageName",packageName);    appResourcesFormMap.put("versionCode", versionCode);    System.out.println(appResourcesFormMap);    //model.addAttribute("appresources", appResourcesFormMap);    JSONObject fromObject = JSONObject.fromObject(appResourcesFormMap);    //String string = fromObject.toString();    return fromObject;}