效果图
jsp上传前端代码
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title></title>
<style type="text/css">
* {
padding: 0px;
margin: 0px;
}
body {
background: #394E48;
font-size: 14px;
font-family: "微软雅黑";
}
.title {
text-align: center;
color: #fff;
margin-top: 50px;
}
.demo {
width: 900px;
height: 140px;
margin: 50px auto;
}
.drag-area {
width: 100%;
height: 100px;
border: 3px dashed #fff;
text-align: center;
line-height: 100px;
color: #fff;
font-size: 36px;
font-weight: 700;
}
}
.preview div {
width: 195px;
overflow: hidden;
border: 1px dashed silver;
margin-top: 10px;
float: left;
padding: 9px;
text-align: center;
height: 168px;
}
.preview img {
width: 80px;
height: 80px;
}
</style>
</head>
<body>
<h1 class="title">小夜的传说最新力作！Java实现拖拽上传！！</h1>
<div class="demo">
<div class="drag-area" id="upload-area">
将图片拖拽到这里
</div>
<!-- 图片预览 -->
<div id="preview" class="preview"></div>
</div>
</body>
<script type="text/javascript">
//1、文件上传HTML5 通过drag把文件拖拽到浏览器的默认事件覆盖
//文件离开
document.ondragleave=function(e){
e.preventDefault();
console.info("文件离开执行了我！！");
};
//鼠标松开文件
document.ondrop=function(e){
e.preventDefault();
console.info("松开以后执行了我！");
};
//鼠标移动文件
document.ondragover=function(e){
e.preventDefault();
console.info("文件移动以后执行了我！");
};
function tm_upload(){
var img1="";
var uploadArea=document.getElementById("upload-area");
//2、通过HTML5拖拽事件，ondrop，然后通过拖动区域监听浏览器的drop事件达到文件上传的目的
uploadArea.addEventListener("drop", function(e){
e.preventDefault();
//3、从事件event中获取拖拽到浏览器的文件信息
var fileList=e.dataTransfer.files;
for(var i=0;i<fileList.length;i++){
//此处判断只能上传图片
if(fileList[i].type.indexOf("image")!=0){
alert("请上传图片");
return;
}
//图片预览 这一步需要判断是什么浏览器 大家自己判断吧
/*************************************/
img1=window.URL.createObjectURL(fileList[i]);
/*************************************/
var str="<div><img src='"+img1+"'/ alt="Java實作拖曳上傳" ><p>"+fileList[i].name+"</p></div>";
document.getElementById("preview").innerHTML +=str;
var fileName=fileList[i].name;
console.info(fileName);
var fileSize=fileList[i].size;
console.info(fileSize);
//4、通过XMLHttpRequest上传文件到服务器 就是一个ajax请求
var xhr=new XMLHttpRequest();
//5、这里需要先写好一个data.jsp的上传文件，当然，你写成servlet或者是action都可以
xhr.open("post","data.jsp",true);
xhr.setRequestHeader("X-Request-Width", "XMLHttpRequest");
//6、通过HTML5 FormData动态设置表单元素
var formData=new FormData();//动态给表单赋值，传递二进制文件
//其实就相当于<input type="file" name="file"/>
formData.append("doc",fileList[i]);
xhr.send(formData);
}
});
}
//直接调用
tm_upload();
</script>
</html>ok，编写完前台代码，在写后台，如下:
<%@page import="java.util.UUID"%>
<%@page import="org.apache.commons.fileupload.FileItem"%>
<%@page import="java.util.Iterator"%>
<%@page import="java.util.List"%>
<%@page import="org.apache.commons.fileupload.servlet.ServletFileUpload"%>
<%@page import="org.apache.commons.fileupload.disk.DiskFileItemFactory"%>
<%@page import="org.apache.commons.fileupload.FileItemFactory"%>
<%@page import="java.io.File"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%
/*
1、文件上传:
*/
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
//获取文件路径
String strPath=request.getRealPath("/")+"/upload";
File file =new File(strPath);
if(!file.exists())file.mkdirs();
FileItemFactory factory=new DiskFileItemFactory();
ServletFileUpload upload=new ServletFileUpload(factory);
//从请求对象中获取文件信息
List items= upload.parseRequest(request);
if(items!=null){
for(int i=0;i<items.size();i++){
Iterator iterator=items.iterator();
while(iterator.hasNext()){
FileItem item=(FileItem)iterator.next();
if(item.isFormField()){
continue;
}else{
String fileName=item.getName();
Long fileSize=item.getSize();
int pos=fileName.indexOf(".");
String ext=fileName.substring(pos,fileName.length());
fileName=UUID.randomUUID().toString()+ext;
File saveFile=new File(strPath,fileName);
item.write(saveFile);
}
}
}
}
%>
