HTML5拖拽文件到浏览器并实现文件上传下载

jopen 11年前

先上代码,写的jsp页面,后台是tomcat服务器,所以页面里有一些java的代码,如果后台用其他语言可以无视:

<%@ page language="java" contentType="text/html; charset=UTF-8"   pageEncoding="UTF-8"%>  <%@page import="java.io.*"%>  <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">  <html>  <head>  <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">  <title>上传、下载文件</title>  <style type="text/css">  #filedrag {   display: none;   font-weight: bold;   text-align: center;   padding: 1em 0;   margin: 1em 0;   color: #555;   border: 2px dashed #555;   border-radius: 7px;   cursor: default;  }    #filedrag.hover {   color: #f00;   border-color: #f00;   border-style: solid;   box-shadow: inset 0 3px 4px #888;  }  </style>  </head>  <body>   <form id="upload" action="UploadServlet" enctype="multipart/form-data"    method="post" onsubmit="return upLoad();">    <p>     <label for="fileselect">file name:</label><input multiple="true"      type="file" id="fileselect" name="fileselect[]" />    <div id="filedrag">或者将文件拖拽到这里</div>    <div id="submitbutton">     <input type="submit" value="提交">    </div>   </form>   <div id="messages">     </div>   <% //java代码,显示服务器上可以供下载的文件    File f = new File("G://defggg/");    File[] list = f.listFiles();    for (int i = 0; i < list.length; ++i) {     System.out.println(list[i].getName());     out.print("<a href='DownloadServlet?filename="       + list[i].getName() + "'>" + list[i].getName()       + "</a><br/>");    }   %>   <script type="text/javascript">    var upfiles = new Array();    // getElementById    function $id(id) {     return document.getElementById(id);    }      // output information    function Output(msg) {     var m = $id("messages");     m.innerHTML = msg + m.innerHTML;    }      // file drag hover    function FileDragHover(e) {     e.stopPropagation();     e.preventDefault();     e.target.className = (e.type == "dragover" ? "hover" : "");    }      // file selection    function FileSelectHandler(e) {       // cancel event and hover styling     FileDragHover(e);       // fetch FileList object     var files = e.target.files || e.dataTransfer.files;       // process all File objects     for ( var i = 0, f; f = files[i]; i++) {      ParseFile(f);      upfiles.push(f);     }            }      // output file information    function ParseFile(file) {       Output("<p>文件信息: <strong>" + file.name       + "</strong> 类型: <strong>" + file.type       + "</strong> 大小: <strong>" + file.size       + "</strong> bytes</p>");    }    function upLoad() {     if (upfiles[0]) {      var xhr = new XMLHttpRequest();   //Ajax异步传输数据      xhr.open("POST", "UploadServlet", true);      var formData = new FormData();      for ( var i = 0, f; f = upfiles[i]; i++) {       formData.append('myfile', f);      }      xhr.send(formData);      xhr.onreadystatechange=function(e){       history.go(0);  //由于这个页面还要显示可以下载的文件,所以需要刷新下页面      }          return false;     }    }    // initialize    function Init() {       var fileselect = $id("fileselect"), filedrag = $id("filedrag"), submitbutton = $id("submitbutton");       // file select     fileselect.addEventListener("change", FileSelectHandler, false);       // is XHR2 available?     var xhr = new XMLHttpRequest();     if (xhr.upload) {        // file drop      filedrag.addEventListener("dragover", FileDragHover, false);      filedrag.addEventListener("dragleave", FileDragHover, false);      filedrag.addEventListener("drop", FileSelectHandler, false);      filedrag.style.display = "block";      // remove submit button      //submitbutton.style.display = "none";     }      }      // call initialization file    if (window.File && window.FileList && window.FileReader) {     Init();    }   </script>  </body>  </html>

附上后台处理上传下载的servlet,用了smartUpLoad,不能很好的解决中文问题:

package com.hit.software;    import java.io.IOException;    import javax.servlet.ServletConfig;  import javax.servlet.ServletException;  import javax.servlet.annotation.WebServlet;  import javax.servlet.http.HttpServlet;  import javax.servlet.http.HttpServletRequest;  import javax.servlet.http.HttpServletResponse;    import com.jspsmart.upload.Files;  import com.jspsmart.upload.SmartUpload;    /**   * Servlet implementation class UploadServlet   */  @WebServlet("/UploadServlet")  public class UploadServlet extends HttpServlet {   private static final long serialVersionUID = 1L;   private ServletConfig config;     final public void init(ServletConfig config) throws ServletException {    this.config = config;   }     /**    * @see HttpServlet#HttpServlet()    */   public UploadServlet() {    super();    // TODO Auto-generated constructor stub   }     /**    * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse    *      response)    */   protected void doGet(HttpServletRequest request,     HttpServletResponse response) throws ServletException, IOException {    doPost(request, response);   }     /**    * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse    *      response)    */   protected void doPost(HttpServletRequest request,     HttpServletResponse response) throws ServletException, IOException {    request.setCharacterEncoding("UTF-8");    // String s = request.getParameter("pic");    // System.out.println(s);    SmartUpload mySmartUpload = new SmartUpload();    try {     mySmartUpload.initialize(config, request, response);     mySmartUpload.setMaxFileSize(150 * 1024 * 1024);     mySmartUpload.setTotalMaxFileSize(150 * 1024 * 1024);     // mySmartUpload.setAllowedFilesList("doc,txt,rar,pdf,png");     mySmartUpload.setDeniedFilesList("exe");     mySmartUpload.upload();     Files f = mySmartUpload.getFiles();     int size = f.getCount();     for (int i = 0; i < size; ++i) {      String fileName = mySmartUpload.getFiles().getFile(i)        .getFileName();      fileName = new String(fileName.trim().getBytes(), "UTF-8"); //能解决部分中文问题      System.out.println("filename=" + fileName);      if (!fileName.equals("")) {       String path = "g:/defggg/" + fileName;       f.getFile(i).saveAs(path, SmartUpload.SAVE_PHYSICAL);      }     }    } catch (Exception e) {     e.printStackTrace();     System.out.println("Unable to upload the file.");     System.out.println("Error :" + e.toString());    }    response.sendRedirect("index.jsp");   }  }

package com.hit.software;    import java.io.File;  import java.io.IOException;    import javax.servlet.ServletConfig;  import javax.servlet.ServletException;  import javax.servlet.annotation.WebServlet;  import javax.servlet.http.HttpServlet;  import javax.servlet.http.HttpServletRequest;  import javax.servlet.http.HttpServletResponse;  import javax.servlet.jsp.JspFactory;  import javax.servlet.jsp.JspWriter;  import javax.servlet.jsp.PageContext;    import com.jspsmart.upload.SmartUpload;  import com.jspsmart.upload.SmartUploadException;    /**   * Servlet implementation class DownloadServlet   */  @WebServlet("/DownloadServlet")  public class DownloadServlet extends HttpServlet {   private static final long serialVersionUID = 1L;   private ServletConfig config;     /**    * @see HttpServlet#HttpServlet()    */   public DownloadServlet() {    super();    // TODO Auto-generated constructor stub   }     final public void init(ServletConfig config) throws ServletException {    this.config = config;   }     /**    * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse    *      response)    */   protected void doGet(HttpServletRequest request,     HttpServletResponse response) throws ServletException, IOException {    doPost(request, response);   }     /**    * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse    *      response)    */   protected void doPost(HttpServletRequest request,     HttpServletResponse response) throws ServletException, IOException {    request.setCharacterEncoding("UTF-8");    String fileName = request.getParameter("filename");    System.out.println("down :"+fileName);    if (fileName == null) {     response.sendRedirect("index.jsp");     return;    }    fileName = "G://defggg//" + fileName;    File f = new File(fileName);    if (f.exists() && f.isFile()) {     SmartUpload su = new SmartUpload();     su.initialize(config, request, response);     su.setContentDisposition(null);     try {      su.downloadFile(fileName);     } catch (SmartUploadException e) {      // TODO Auto-generated catch block      e.printStackTrace();     }    } else {     response.sendRedirect("index.jsp");     return;    }   }    }


参考:http://www.sitepoint.com/html5-file-drag-and-drop/