Java实现拖拽文件上传dropzone.js的简单使用示例代码

Java实习生一枚，前端知识薄弱，最近因为工作需要，做了一个拖拽文件上传的功能，发现dropzone.js挺不错的，特地做个笔记。

dropzonejs 的官网是：http://www.dropzonejs.com/， 中文手册是：http://wxb.github.io/dropzonejs.com.zh-CN/

自己写的拖拽文件至一个按钮上传的功能，前端及java代码如下：

jsp页面：

1. 首先必须引入dropzone的js和css文件

<link rel="stylesheet" href="dropzone/css/dropzone.css" rel="external nofollow" >
<script src="dropzone/js/dropzone.js"></script> 

2.自己定义两个div区域

<%--拖拽文件上传 --%>
            <div id="div1" class="dropz" style="width:0px; height:0px;">
             uopload
            </div>
            <div id="div2" class="dropz" style=" background: white;border:none;float:left;"> 

            </div>

这是我的文件上传之后的文件队列区域：

<div id="fileslist" style="padding: 10px;"></div> 

3.对dropzone.css进行修改，将文件内的所有dropzone替换为dropz

修改文件拖拽区域的显示样式：

.dropz {/*设置拖拽上传文件按钮的格式*/
  min-height:0px;
  min-width: 100px;
  border: 1px solid #58AF0C;
  background: white;
  padding: 15px 20px;
  background-color: #7AC143;
  background-image: -webkit-gradient(linear, left bottom, left top, color-stop(0, #7AC143),
    color-stop(1, #7AC143));
  background-position: center top;
  background-repeat: no-repeat;
  border-radius: 5px;
  min-height:0px;
  min-width: 100px;
  padding: 15px 20px;
  color: #FFF;
  font: bold 12px Arial, Helvetica, sans-serif;
  text-align: center;
  text-shadow: 0 -1px 0 rgba(0, 0, 0, 0.25);
 }
 .dropz.dz-clickable {
  cursor: pointer;
  line-height: 0px;/*按钮中的文字垂直居中*/
   }

4.在jsp对div进行dropzone参数的自定义

<script type="text/javascript">
  $("#div1").dropzone({
  url:"systemController.action?saveFile",//上传文件的地址，
  maxFiles:1,//最多上传几个文件
  maxFilesize: 5,//文件的大小，单位是M
  addRemoveLinks:true,//是否有删除文件的功能
  dictRemoveFile:"",//删除文件
  previewsContainer:"#div2",//文件上传进度显示的区域
  acceptedFiles: ".jpg,.jpeg,.png,.gif,.xls,.txt,.sql,.rar,.mkv",//支持的格式
  paramName:'file',//上传的FILE名称，即服务端可以通过此来获取上传的文件，如$_FILES['dropimage']
  init: function() {//初始化时的事件
    //$("#uploadfile").uploadFile({success:function(data){
     this.on("addedfile", function(file) { 

      // Create the remove button
      var removeButton = Dropzone.createElement("<img src='plug-in/uploadify/img/uploadify-cancel.png' title='删除'/>"); 

      // Capture the Dropzone instance as closure.
      var _this = this; 

      // Listen to the click event
      removeButton.addEventListener("click", function(e) {
       // Make sure the button click doesn't submit the form:
       e.preventDefault();
       e.stopPropagation();
       alert("Are you sure to delete?");
       // Remove the file preview.
       _this.removeFile(file);
       // If you want to the delete the file on the server as well,
       // you can do the AJAX request here.
      });
      // Add the button to the file preview element.
      file.previewElement.appendChild(removeButton);
      });
      this.on("success", function(file, data) {
        if (this.getUploadingFiles().length === 0 && this.getQueuedFiles().length === 0) {
          var d = $.parseJSON(data);
          var fileitem = "<span class='uploadFile-queue-item' id='" + d.fileKey + "'><a>" + d.name
          + "</a><img border='0' style='padding:2px;cursor:pointer;' onclick=delAttachment('" + d.delurl + "','"
          + d.fileKey + "','" + d.name
          + "') title='删除' src='plug-in/uploadify/img/uploadify-cancel.png' widht='15' height='15'> </span>";
         $("#fileslist").html(fileitem);
         $("#attachment").val(d.fileKey + "," + d.name + ";");
        }
        this.removeFile(file);
      });
    }
});
</script>

java后台处理文件上传的代码：

@RequestMapping(params = "saveFile", method = RequestMethod.POST)
  public void saveFile(HttpServletRequest request, HttpServletResponse response, TSDocument document) throws Exception{
    Map<String, Object> attributes = new HashMap<String, Object>();
    TSTypegroup tsTypegroup=systemService.getTypeGroup("fieltype","文档分类");
    TSType tsType = systemService.getType("files","附件", tsTypegroup);
    String fileKey = oConvertUtils.getString(request.getParameter("fileKey"));// 文件ID
    String documentTitle = oConvertUtils.getString(request.getParameter("documentTitle"),"uploadfile");// 文件标题
    if (StringUtil.isNotEmpty(fileKey)) {
      document.setId(fileKey);
      document = systemService.getEntity(TSDocument.class, fileKey);
      document.setDocumentTitle(documentTitle); 

    }
    document.setBusinessKey(request.getParameter("businessKey"));
    document.setSubclassname(MyClassLoader.getPackPath(document));
    document.setCreatedate(DateUtils.gettimestamp());
    document.setTSType(tsType);
    UploadFile uploadFile = new UploadFile(request, document);
    uploadFile.setCusPath("files");
    uploadFile.setSwfpath("swfpath");
    document = systemService.uploadFile(uploadFile);
    attributes.put("url", document.getRealpath());
    attributes.put("fileKey", document.getId());
    if (ResourceUtil.getSessionUserName()!=null) {
      attributes.put("uploadUser", ResourceUtil.getSessionUserName().getUserName());
    }else{
      attributes.put("uploadUser", "null");
    }
    attributes.put("time", new SimpleDateFormat("yyyy-MM-dd").format(new Date()));
    attributes.put("name", document.getAttachmenttitle()+"."+document.getExtend());
    attributes.put("downloadurl", "commonController.action?viewFile&fileid="+ document.getId()+"&subclassname=");
    attributes.put("viewhref", "commonController.action?objfileList&fileKey=" + document.getId());
    attributes.put("delurl", "commonController.action?delObjFile&fileKey=" + document.getId());
    attributes.put("realPath", document.getRealpath());
    if(FileUtils.isPicture(document.getExtend())){
      attributes.put("imgUrl", document.getRealpath());
    }
    JSONObject js = new JSONObject(attributes);
    response.getWriter().write(js.toString());
    response.getWriter().flush();
  }

注意这里的返回值是直接返回的json对象，如果采用

@RequestMapping(params = "saveFiles", method = RequestMethod.POST)
  @ResponseBody

则会报错:

代码如下:

[com.framework.core.common.exception.MyExceptionHandler]org.springframework.web.HttpMediaTypeNotAcceptableException: Could not find acceptable representation

最终实现的效果如下：

更多使用功能请参考dropzone的官方文档。

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