java 文件上傳顯示進度

chyx413332087 13年前發布 | 6K 次閱讀

實現功能：通過在頁面中上傳文件，到ftp服務器

頁面用得html標簽 <input type="file"/> 在表單中，設置表單，請求文件頭，enctype="multipart/form-data"，我用得apache fileUpload,結合 apache Ftp ，代碼很簡單，網上到處都有，但是有點注意， fileUpload,是會再web服務器，創建一個temp目錄，將文件讀到臨時目錄，如果不顯示設置臨時目錄，會再web服務器目錄，也可以自己顯示設置臨時目錄， apache ftp 實際是讀取臨時目錄流，到指定的 ftp 服務器主機地址，原來找了很多資料，想知道如何搞進度條，原來在 apache fileUploade,有個監聽器，可以監聽流每次讀取的文件信息， org.apache.commons.fileupload。

/* pBytesRead 到目前為止讀取文件的比特數
* pContentLength 文件總大小
* pItems 目前正在讀取第幾個文件
*/

public interface ProgressListener {

public abstract void update(long pBytesRead , long pContentLength , int i);
}

implement 這個接口，

在文件上傳的時候

ServletFileUpload upload = new ServletFileUpload(factory);
progressListen getBarListener = new progressListen(request);
upload.setProgressListener(getBarListener);

有個問題一定要注意，一定要寫在 ServletFileUpload 初始對象后面，不然，會讀不到數據，這個要看源代碼就知道，在upload.write（）里面，有對getBarListener !=null 的判斷，因此要寫在初始對象后面，我為這個事，發了不少的實際，

在頁面方面，需要搞個ajax ，調用一個請求，請求里面能讀取到getBarListener 里面的update（），設置的數據，用個windows.setTimeOut(,5000),不斷調用，不能太快，太快的話，頁面基本是白色的，反應不過來

2:上面用windows.setTimeOut實時性不是很強，但是如果要狠強的實時性，可以采用服務器推得技術，由服務器主動發現客戶端，這就要去研究了哦，

3：在html5 下解決就很容易了，html5是雙工通信，長連接的

下面是簡易代碼：

public class progressListen   implements ProgressListener {
    private HttpSession session;

   public progressListen(HttpServletRequest request)
   {
  this.session=request.getSession();
  this.session.setAttribute("fileAttr", "ttttttttttttt");



   }

/* pBytesRead 到目前為止讀取文件的比特數
* pContentLength 文件總大小
* pItems 目前正在讀取第幾個文件
*/
public void update(long pBytesRead, long pContentLength, int pItems) {


  session.setAttribute("byte", String.valueOf(pBytesRead));
  session.setAttribute("pContentLength", String.valueOf(pContentLength));

  System.out.println("update="+String.valueOf(pBytesRead));
}

}

public class ProgressServlet extends HttpServlet {

/**
* Constructor of the object.
*/
public ProgressServlet() {
super();
}

/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}

  //response.setContentType("text/html");
  System.out.println("id="+request.getSession().getId());

  System.out.println("isNew="+request.getSession().isNew());

  PrintWriter out = response.getWriter();


  String b=(String)request.getSession().getAttribute("byte");
  String pContentLength=(String)request.getSession().getAttribute("pContentLength");
  String fileAttr=(String)request.getSession().getAttribute("fileAttr");

  System.out.println("bbb="+b);
  System.out.println("1212=="+pContentLength);

  out.println("<HTML>");
  out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
  out.println(" <BODY>");
  out.println(request.getSession().getId());
   out.println(fileAttr);
   out.println("bb="+b);
   out.println("1212="+pContentLength);
      out.println(" </BODY>");
  out.println("</HTML>");
  out.flush();
  out.close();
}

/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}

/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}

}

public class UploadFileAction extends HttpServlet {

/**
* Constructor of the object.
*/
public UploadFileAction() {
super();
}

/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}

/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {


    response.reset();

// response.setContentType("text/html"); application/octet-stream
       response.setContentType("application/x-download");
// response.setContentType("application/octet-stream");



  String file_name=request.getParameter("file_name");

  System.out.println("file_name="+file_name);
  //response.setHeader("Content-Disposition","attachment;filename=" + file_name);
// response.addHeader("Content-Disposition","attachment;filename=" + file_name);

  //加上下面的這句話，下載下來的圖片，打開為空白，當是大小一樣
  response.setHeader("Content-Disposition", "attachment;filename=\"" + file_name + "\"" );
  //response.setHeader("Cache-Control", "private");

//setHeader("Cache-Control", "private");
java.io.File ff=new File("F:/java/apache-ftpserver-1.0.5/res/home/"+file_name);

  //構建下載文件的對象

      //獲得文件的長度
  long filesize = ff.length();
      //設置輸出格式
  //response.addHeader("content-type", "application/x-msdownload;");
  //response.addHeader("Content-Disposition", "attachment; filename=" + response.encodeURL(file_name));
    response.addHeader("content-length", Long.toString(filesize));

  //System.out.println("ssss="+ff.getAbsolutePath());
  //System.out.println("ssss="+ff.isFile());


  FTPClient ftpClient=new FTPClient();
  ftpClient.connect("127.0.0.1", 2121);
  ftpClient.login("admin", "admin");
  ftpClient.enterLocalPassiveMode();

  ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
  ftpClient.addProtocolCommandListener(new PrintCommandListener(
                new PrintWriter(System.out)));
  FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_NT);
        conf.setServerLanguageCode("zh");
    OutputStream outputStream=response.getOutputStream();

        boolean b = ftpClient.retrieveFile(file_name, outputStream);

     if(b)
      System.out.println("下載成功!");
     else
      System.out.println("下載失敗!");
     outputStream.flush();
     outputStream.close();
  //FTPFile ftpFile=ftpClient.mlistFile(file_name);

// System.out.println("ftpFile.isFile="+ftpFile.isFile());
      // java.io.File f=new File(file_name);
// java.io.OutputStream file=new FileOutputStream(f);
     //   System.out.println(ftpClient.printWorkingDirectory());

//java.io.InputStream input= ftpClient.retrieveFileStream(file_name);
          /*
  java.io.InputStream input =new FileInputStream(ff);
     byte r[]=new byte[1024];
  OutputStream outputStream=response.getOutputStream();

         int c=-1;

  while((c=input.read(r))>0)
  {
   outputStream.write(r, 0, c);
  }
  outputStream.flush();


   outputStream.close();
   input.close();
   response.flushBuffer();
   */
  // response.sendRedirect("index.jsp");
  // outputStream.close();




  /*

  boolean b =ftpClient.retrieveFile(file_name, file);

     if(b)
      System.out.println("下載成功!");
     else
      System.out.println("下載失敗!");
  */

    //file.flush();
     //file.close();
    // response.flushBuffer();

  //outputStream.flush();


    // file.flush();
     //file.close();
    // ftpClient.logout();
    //ftpClient.disconnect();
    //outputStream.close();
    // response.flushBuffer();

}

// response.setContentType("text/html");
  PrintWriter out = response.getWriter();
  response.setCharacterEncoding("GBK");
  out.println("uri="+request.getRequestURI());
  out.println("url="+request.getRequestURL());



  try
  {
  boolean   isMult=ServletFileUpload.isMultipartContent(request);
  if(isMult==true) //說明是
  {
   DiskFileItemFactory factory = new DiskFileItemFactory();
   ServletFileUpload upload = new ServletFileUpload(factory);
   progressListen getBarListener = new progressListen(request);
   upload.setProgressListener(getBarListener);

   List<FileItem> items = upload.parseRequest(request);
   Iterator<FileItem> itr = items.iterator();
   while (itr.hasNext()) {
    FileItem item = (FileItem) itr.next();

    //檢查當前項目是普通表單項目還是上傳文件。
    if (item.isFormField()) {
     //如果是普通表單項目，顯示表單內容。
     String fieldName = item.getFieldName();
     if (fieldName.equals("name"))
                          out.println("ssssss="+fieldName);
     }
    else { //如果是上傳文件，顯示文件名。

     out.print("<br>");

     File fullFile = new File(item.getName());

     out.print("<br>="+fullFile.getName());

     out.print("lujin="+fullFile.getAbsolutePath());

     out.print("<br>111="+fullFile.getPath());

    // item.write(fullFile);

     FTPClient ftpClient=new FTPClient();

     ftpClient.connect("127.0.0.1", 2121);
     ftpClient.login("admin", "admin");
     out.print(ftpClient.getRemotePort());
     ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
     ftpClient.setControlEncoding("GBK");
     ftpClient.addProtocolCommandListener(new PrintCommandListener(
                              new PrintWriter(System.out)));
     //out.println(ftpClient.getReplyCode());
     //設置上傳工作目錄   不設置，默認 res\home
     //ftpClient.changeWorkingDirectory("/");
    // FileInputStream fileInputStream=new FileInputStream(fullFile);
     String newFileName="test_"+new Random().nextInt(10000)+".JPG";
      ftpClient.storeFile(newFileName,item.getInputStream());

      ftpClient.logout();
      ftpClient.disconnect();

      //上傳的文件名
      out.print("the upload file name is " + newFileName);
      // downFile(newFileName,out);
     }
    }
   }
  }catch(Exception e)
  {
  e.printStackTrace();
  }
}

public void downFile(String remoteFileName,PrintWriter out ) throws Exception
{

  FTPClient ftpClient=new FTPClient();
  ftpClient.connect("127.0.0.1", 2121);
  ftpClient.login("admin", "admin");
  ftpClient.addProtocolCommandListener(new PrintCommandListener(
                new PrintWriter(System.out)));
  ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
  String fileName[]=ftpClient.listNames();

  java.io.File f=new File(".\\"+fileName[4]);
  System.out.println("本地路徑="+f.getAbsolutePath());

    java.io.OutputStream file=new FileOutputStream("./"+fileName[4]);
   file.flush();
  boolean b=ftpClient.retrieveFile("test_4258.jpeg", file);

    if(b)
     System.out.println("成功!");
    else
     System.out.println("失敗!");

  file.flush();
  ftpClient.logout();
  ftpClient.disconnect();
  file.close();
  for (int i=0;i<fileName.length;i++)
  {out.println("<br>");
   out.println("fileName="+fileName[i]);
  }
}

/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
}

}

function getBarPress()
{
var request=new XMLHttpRequest();
     var sendUrl="http://127.0.0.1:8080/webTest/servlet/ProgressServlet";
   request.open("GET", sendUrl);
         request.onreadystatechange = function() {
                    if (request.readyState == 4) {
                        if (request.status == 200){
                          document.getElementById("forecasts").innerHTML = request.responseText;
                        }
                    //   getBarPress();
                    }
                };
                request.send(null);

       /**
if(request.readyState==4)
{
     if(request.status==200)
    {
     alert(request.responseText);
    document.getElementById("xianShi").innerHTML = request.responseText;
       }
}

request.send(null);
**/

window.setTimeout("getBarPress()",4000);
}

function onbuttommit()
{
var formid=document.getElementById("uploadForm");
formid.submit();

window.setTimeout("getBarPress()", 7000);
}

</script>

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