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前端通过form表单用post方式提交文件，后台进行保存处理。此处省略较多注释及其他功能，仅保留上传文件功能，建议阅读原文学习。
前端：
<!DOCTYPE html> <html> <head> <meta name="content-type" content="text/html; charset=UTF-8"> <title>发布商品</title> </head> <body> <form action="../com/yh/myServlet/AddGoodsServlet" enctype="multipart/form-data" method="post"> 上传文件：<input type="file" name="picture"> <br/> <input type="submit" value="提交"> </form> </body> </html>
后端：
package com.yh.myServlet; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.util.List; import java.util.UUID; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; public class AddGoodsServlet extends HttpServlet { /** * */ private static final long serialVersionUID = 1L; @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub response.setContentType("text/html;charset=utf-8"); String savePath = this.getServletContext().getRealPath("/WEB-INF/upload"); savePath = savePath.replace("\", "\\"); File file = new File(savePath); if (!file.exists()) { file.mkdir(); } InputStream in = null; FileOutputStream out = null; try { DiskFileItemFactory factory = new DiskFileItemFactory(); ServletFileUpload upload = new ServletFileUpload(factory); upload.setHeaderEncoding("UTF-8"); List<FileItem> list = upload.parseRequest(request); for (FileItem item : list) { String filename = item.getName(); if (filename == null || filename.trim().equals("")) { continue; } filename = filename.substring(filename.lastIndexOf(".") + 1); filename = UUID.randomUUID().toString() + "." + filename; out = new FileOutputStream(savePath + "\\" + filename); byte[] buffer = new byte[1024]; int len = 0; in = item.getInputStream(); while ((len = in.read(buffer)) > 0) { out.write(buffer, 0, len); } item.delete(); } } catch (Exception e) { e.printStackTrace(); } finally { in.close(); out.close(); } } }