SWFUpload详解 java后台接收实例(包括传参问题)

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一、简介和示例

SWFUpload is a small JavaScript/Flash library to get the best of both worlds. It features the great upload capabilities of Flash and the accessibility and ease of HTML/CSS。

官方站点:http://www.swfupload.org/

简单来说,swfupload这个上传库是可以显示上传进度以及上传速度等上传信息。一般实现这种上传体验有2种方式,一种是异步上传,在服务器端边接收数据边往session写入接收的字节数和进度数据,然后客户端轮询这个记录在session的进度数据并回显到页面。第二种方式就是采用flash来上传,也就是swfupload所采用的方式,在发送过程中将发送的相关状态数据回传到js的函数中处理。

二、参数说明

原理是很明显易懂的,关键是flash和javascript的通讯部分,在文件上传的各个状态都会有javascript和flash函数的相互回调。目前主要研究了上传单个文件的上传逻辑,swfupload支持多个文件上传的,不过核心的逻辑应该是没有太多的变化。swfupload用一个队列来管理多个文件上传的,因为在传入的参数中会有一些队列和文件上传数量相关的参数。

在其核心的JavaScript文件swfupload.js定义的状态码以及从flash传递到js的文件对象:

//文件对象file = {    "id":SWFUpload_0_0,    "index":0,    "filestatus":-1,    "name":vim-cheat-sheet-diagram.png,    "size":317949,    "type":"",    "creationdate":Fri Jan 16 1970 00:08:13 GMT+0800 (CST),    "modficationdate":Fri Jan 16 1970 00:08:13 GMT+0800 (CST),    "post": {}}//文件队列错误码SWFUpload.QUEUE_ERROR = {    QUEUE_LIMIT_EXCEEDED            : -100,    FILE_EXCEEDS_SIZE_LIMIT         : -110,    ZERO_BYTE_FILE                  : -120,    INVALID_FILETYPE                : -130};//上传错误码SWFUpload.UPLOAD_ERROR = {    HTTP_ERROR                      : -200,    MISSING_UPLOAD_URL              : -210,    IO_ERROR                        : -220,    SECURITY_ERROR                  : -230,    UPLOAD_LIMIT_EXCEEDED           : -240,    UPLOAD_FAILED                   : -250,    SPECIFIED_FILE_ID_NOT_FOUND     : -260,    FILE_VALIDATION_FAILED          : -270,    FILE_CANCELLED                  : -280,    UPLOAD_STOPPED                  : -290};//文件状态SWFUpload.FILE_STATUS = {    QUEUED       : -1,    IN_PROGRESS  : -2,    ERROR        : -3,    COMPLETE     : -4,    CANCELLED    : -5};//按钮的动作SWFUpload.BUTTON_ACTION = {    SELECT_FILE  : -100,    SELECT_FILES : -110,    START_UPLOAD : -120};

1. 事件处理函数

事件函数触发时间参数swfupload_loaded_handler在flash初始化完成之后没有参数file_dialog_start_handler当用户点击上传按钮,在打开文件浏览窗口之前没有参数file_queued_handler用户成功地选择了文件,在file_dialog_complete_handler事件之前触发。如果选择了多个文件,则触发多次file文件对象file_queue_error_handler文件上传数量、类型、大小不符合时file文件对象、错误码、从flash中返回的错误信息file_dialog_complete_handler在用户成功了选择了文件后,在所有file_queued_handler之后触发选择文件的数量、加入了文件队列的文件数量、在当前文件队列总共的文件数量upload_start_handler用户点击了提交按钮,开始把文件上传到服务器file文件对象upload_progress_handler刚打开与服务器的连接与文件上传过程中file文件对象、已经上传的字节数、总共要上传的字节数upload_error_handler上传失败时file文件对象、错误码、从flash中返回的错误信息upload_success_handler文件上传成功或者等待服务器数据返回超时file文件对象、服务器返回的数据、服务器是否有返回数据upload_complete_handler上传完成时,在upload_success_handler之后触发file文件对象debug_handler调用SWFUpload对象的debug()函数时swfupload对象和其初始化的参数

2. 其他重要参数

参数名意义说明upload_url要上传到的服务器地址 file_post_name上传到服务器中文件内容对应的key flash_urlflash元素的url custom_settings自定义的参数,可以在事件处理函数中获取得到dict类型button_placeholder_idflash的上传按钮显示在html的位置,此名称的元素会被替换成object元素span即可

三、上传逻辑

下面是用graphviz画出来的流程图,图比较大,不过看得舒服:)
1. 如上面的示例代码所示,在javascript代码中首先要创建一个SWFUpload的javascript对象,这个对象创建的初始化逻辑如下(箭头表示逻辑和流程的走向):
js_swfupload
2. 当javascript将object元素添加到html页面的元素中时,即初始化flash中的元素:
flash_swfupload
3.用户点击上传的按钮,准备选择文件时,这个已经绑定了按钮的点击事件,而这个按钮不是input而是一个flash的元素:
open_filebrowser
4.用户选择完文件后:
select_file
5. 用户点击提交按钮,文件开始上传到服务器:
submit_upload
6. 文件上传过程中的一些事件处理逻辑:
upload_events


实例代码(注意要在服务器部署之后下浏览才有效
上代码:
一、前台页面index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="GB18030"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <base href="<%=basePath%>">         <title>文件上传swfupload使用</title>    <meta http-equiv="pragma" content="no-cache">    <meta http-equiv="cache-control" content="no-cache">    <meta http-equiv="expires" content="0">       <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">    <meta http-equiv="description" content="This is my page">    <!--    <link rel="stylesheet" type="text/css" href="styles.css">    -->    <link href="<%=basePath%>css/default.css" rel="stylesheet" type="text/css" />    <script type="text/javascript" src="<%=basePath%>swfupload/swfupload.js"></script>    <script type="text/javascript" src="<%=basePath%>swfupload/swfupload.queue.js"></script>    <script type="text/javascript" src="<%=basePath%>js/fileprogress.js"></script>    <script type="text/javascript" src="<%=basePath%>js/handlers.js"></script>              <script type="text/javascript">    var swfu;     window.onload = function () {        var settings = {            flash_url : "<%=basePath%>swfupload/swfupload.swf",            flash9_url : "<%=basePath%>swfupload/swfupload_fp9.swf",            upload_url: "<%=basePath%>upload",            post_params: {                "hello" : "Here I Am",                "name" : "张三"            },            file_size_limit : "100 MB",            file_types : "*.*",            file_types_description : "All Files",            file_upload_limit : 100,            file_queue_limit : 0,            custom_settings : {                progressTarget : "fsUploadProgress",                cancelButtonId : "btnCancel"            },            debug: true,            use_query_string : true,//要传递参数,必须配置,可以从后台取到参数,应该还有其他方式,如post方式,未了解                         // Button Settings            button_image_url : "<%=basePath%>images/TestImageNoText_65x29.png",            button_placeholder_id : "spanButtonPlaceholder",            button_width: 61,            button_height: 22,            button_text: '浏览',            button_text_style: ".spanButtonPlaceholder { font-size: 12; }",            button_text_left_padding: 12,            button_text_top_padding: 3,             // The event handler functions are defined in handlers.js            //swfupload_preload_handler : preLoad,            //swfupload_load_failed_handler : loadFailed,            file_queued_handler : fileQueued,            file_queue_error_handler : fileQueueError,            file_dialog_complete_handler : fileDialogComplete,            upload_start_handler : uploadStart,            upload_progress_handler : uploadProgress,            upload_error_handler : uploadError,            upload_success_handler : uploadSuccess,            upload_complete_handler : uploadComplete,            queue_complete_handler : queueComplete  // Queue plugin event                     };         swfu = new SWFUpload(settings);    }    </script>  </head>  <body>        <div class="fieldset flash" id="fsUploadProgress">            <span class="legend">文件列表:</span>            </div>        <div id="divStatus">上传了0个文件</div>         <div class="flash" id="fsUploadProgress">    </div>    <div style="padding-left: 5px;">        <span id="spanButtonPlaceholder"></span>        <input id="btnCancel" type="button" value="取消" onclick="cancelQueue(upload);" disabled="disabled" style="margin-left: 2px; height: 22px; font-size: 8pt;" />    </div>         <!-- 上传文件列表 -->    <div class="fileList" id="fileList">    </div>       </body></html>
二、前台接收后台返回数据的位置 --handler.js-只需要找到该位置,进行修改就可以了
function uploadSuccess(file, serverData) {    try {        var progress = new FileProgress(file, this.customSettings.progressTarget);        progress.setComplete();        progress.setStatus("上传完成.");        progress.toggleCancel(false);        alert(serverData);                 //后台传递回来的内容        var serdata = document.getElementById("fileList");        serdata.innerHTML = serverData;             } catch (ex) {        this.debug(ex);    }}
三、后台servlet-Upload.java,下边只列出了用到的doPost()方法,其他内容都没有变化
public void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {         //接收参数        String hello = request.getParameter("hello");        String name = request.getParameter("name");        name = new String(name.getBytes("ISO-8859-1"),"UTF-8");//字符编码问题,可以通过前台encoding后台再解析                 System.out.println("接收参数,hello="+hello+",name="+name);             String path1 = request.getRequestURI()+"/files";        System.out.println("____________request.getRequestURI():"+path1);        String path2 = request.getSession().getServletContext().getRealPath("/");        System.out.println("_________path2:"+path2);             List<FileEntity> fileList;        fileList = (List)request.getAttribute("fileList");        if(fileList==null)            fileList = new ArrayList<FileEntity>();                 //接收上传文件        String uploadSign = request.getParameter("upload");          String rootPath = request.getParameter("rootPath");          String path = request.getParameter("path");          if(rootPath == null) rootPath = "";            rootPath = rootPath.trim();          if(rootPath.equals("")){            //rootPath = application.getRealPath("/swfupload/files");//自由修改处二:指定服务器固定文件              rootPath = path2+"/files";          }           if(path == null) {            path = rootPath;          }else{            path = new String(Base64.decodeBase64(path.getBytes()));          }          System.out.println(path+"...path.getBytes():"+path.getBytes());          uploadSign = "1";          //上传操作          if(null != uploadSign && !"".equals(uploadSign)){              FileItemFactory factory = new DiskFileItemFactory();              ServletFileUpload upload = new ServletFileUpload(factory);              //upload.setHeaderEncoding("UTF-8");              try{                  List items = upload.parseRequest(request);                  if(null != items){                      Iterator itr = items.iterator();                      int i = 0;                      while(itr.hasNext()){                          FileItem item = (FileItem)itr.next();                          FileEntity file = new FileEntity();//_____________________                          if(item.isFormField()){                              continue;                          }else{                              //自由修改处三:可修改上传后的文件命名方式                              SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMddkkmmss");//以当前精确到秒的日期为上传的文件的文件名                              SimpleDateFormat sdd=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");                              String type = item.getName().split("\\.")[1];//获取文件类型                                                             System.out.println("——————————————————文件名称:"+item.getName());                              System.out.println("从GBK转到UTF-8输出:"+new String(item.getName().getBytes("GBK"),"UTF-8"));                              File savedFile = new File(path,sdf.format(new Date())+"."+type);                                                             //把文件放到列表中,在前台显示                              System.out.println("__________________服务器上对应的文件名称:"+sdf.format(new Date())+"."+type);                              System.out.println("__________________完整路径:"+path1+"/"+sdf.format(new Date())+"."+type);                              file.setId(sdf.format(new Date()));                              file.setDate(sdd.format(new Date()));                              file.setFilename(item.getName());                              file.setFilepath(path1+"/"+sdf.format(new Date())+"."+type);                              file.setFilesize(item.getSize()+"");                              file.setFiletype(type);                              file.setMark("0");                              fileList.add(file);                                                             item.write(savedFile);                          }                      }                  }              }catch(Exception e){                  e.printStackTrace();              }          }                          response.setContentType("text/html");        response.setCharacterEncoding("UTF-8");        PrintWriter out = response.getWriter();        if(fileList!=null){            for(int i=0;i<fileList.size();i++){                FileEntity file = (FileEntity)fileList.get(i);                //out.println("文件:"+ new String(file.getFilename().getBytes("GBK"),"UTF-8")+",文件路径:"+file.getFilepath());                out.println("文件:"+ new String(file.getFilename().getBytes("GBK"),"UTF-8")+",上传成功!");            }        }    }
四、自定义的一个文件类FileEntity.java,测试时全部用的String类型
package com.swfupload.entity;public class FileEntity {    private String id;    private String belong;    private String filename;    private String filepath;    private String filetype;    private String filesize;    private String date;    private String mark;         public FileEntity(){}         public String getId() {        return id;    }    public void setId(String id) {        this.id = id;    }    public String getBelong() {        return belong;    }    public void setBelong(String belong) {        this.belong = belong;    }    public String getFilename() {        return filename;    }    public void setFilename(String filename) {        this.filename = filename;    }    public String getFilepath() {        return filepath;    }    public void setFilepath(String filepath) {        this.filepath = filepath;    }    public String getFiletype() {        return filetype;    }    public void setFiletype(String filetype) {        this.filetype = filetype;    }    public String getFilesize() {        return filesize;    }    public void setFilesize(String filesize) {        this.filesize = filesize;    }    public String getDate() {        return date;    }    public void setDate(String date) {        this.date = date;    }    public String getMark() {        return mark;    }    public void setMark(String mark) {        this.mark = mark;    }         public static void main(String[] agrs){        String str="";        System.out.println(str);    }}

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