HTML5拖拽文件到浏览器并实现文件上传下载功能代码
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2023-12-10 15:24:52
使用HTML5拖拽文件到浏览器并实现文件上传下载，html5的功能是越来越强大了，下面与大家分享下具体的实现代码，感兴趣的朋友可以参考下哈... 13-06-06...
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：
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代码如下:<%@ 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：
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代码如下: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");
}
}
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代码如下: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;
}
}
}