基于servlet的文件上传

<form action="/upload" method="post" enctype="multipart/form-data">
用户：<input type="text" name="username"> <br>
文件：<input type="file" name="imgFile"> <br>
<input type="submit" value="上传">
</form>

<servlet>
<servlet-name>UploadServlet</servlet-name>
<servlet-class>test.mylo.UploadServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>UploadServlet</servlet-name>
<url-pattern>/upload</url-pattern>
</servlet-mapping>

public class UploadServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request,response);
}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1. 获取文件上传的目录路径
String path = request.getSession().getServletContext().getRealPath("/upload/");
//2. 获取日期
String date = new SimpleDateFormat("yyyy-MM-dd ").format(new Date());
//3. 创建目录对象
File file = new File(path+date);
if (!file.exists()){
file.mkdirs();
}


FileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
// 把请求数据转换为FileItem对象
List<FileItem> items = null;
try {
items = upload.parseRequest(request);
} catch (FileUploadException e) {
e.printStackTrace();
}
// 遍历
for(FileItem item : items){
//判断
if(item.isFormField()){
// 普通表单元素如：<input type="text"/>
System.out.println("获取输入用户：" + item.getString("UTF-8"));
}else{
// 文件域：<input type="file" />

// 获取文件名
String fileName = item.getName();
// 获取后缀
String last = fileName.substring(fileName.lastIndexOf("."));
// 处理文件名唯一
String uniqueFileName = UUID.randomUUID().toString().replaceAll("-","") + last;
// 文件上传
try {
item.write(new File(file,uniqueFileName));
} catch (Exception e) {
e.printStackTrace();
}
// 删除临时文件
item.delete();
}
}
}
}