版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/wangtao510/article/details/79866833
//前台页面<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>一个简单的JSP</title>
<script type="text/javascript">
function priview(){
form1.img.src= window.URL.createObjectURL(form1.file1.files[0]);
}
</script>
</head>
<body>
<form action="UploadServlet" method="post" enctype="multipart/form-data" name="form1">
<input type="file" name="file1" onchange="priview()">
<input type="submit" value="上传">
<img alt="" src="" width="100px" height="100px" name="img">
</form>
</body>
</html>UploadServlet protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
String realPath = this.getServletContext().getRealPath("/");
Part p=request.getPart("file1");
if(p.getContentType().contains("image")){
p.write("d:\\a.jpg");
response.getWriter().print("上传成功！");
}
}