本文实例为大家分享了jsp servlet实现文件上传与下载的具体代码,供大家参考,具体内容如下
上传:
需要导入两个包:commons-fileupload-1.2.1.jar,commons-io-1.4.jar
import java.io.File; import java.io.IOException; import java.util.List; 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; /** * 上传附件 * @author new * */ public class UploadAnnexServlet extends HttpServlet { private static String path = ""; public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException { doPost(request,response); } /* * post处理 * (non-Javadoc) * @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse) */ public void doPost(HttpServletRequest request,IOException { path = this.getServletContext().getRealPath("/upload"); try { DiskFileItemFactory factory = new DiskFileItemFactory(); ServletFileUpload up = new ServletFileUpload(factory); List<FileItem> ls = up.parseRequest(request); for (FileItem fileItem : ls) { if (fileItem.isFormField()) { String FieldName = fileItem.getFieldName(); //getName()返回的是文件名字 普通域没有文件 返回NULL // String Name = fileItem.getName(); String Content = fileItem.getString("gbk"); request.setAttribute(FieldName,Content); } else { String nm = fileItem.getName().substring( fileItem.getName().lastIndexOf("\\") + 1); File mkr = new File(path,nm); if (mkr.createNewFile()) { fileItem.write(mkr);//非常方便的方法 } request.setAttribute("result","上传文件成功!"); } } } catch (Exception e) { e.printStackTrace(); request.setAttribute("result","上传失败,请查找原因,重新再试!"); } request.getRequestDispatcher("/pages/admin/annex-manager.jsp").forward( request,response); } }
下载(i/o流)无需导包:
import java.io.IOException; import java.net.URLEncoder; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * 下载文件 * @author * */ public class DownloadFilesServlet extends HttpServlet { /** * */ private static final long serialVersionUID = 8594448765428224944L; public void doGet(HttpServletRequest request,response); } /* * 处理请求 * (non-Javadoc) * @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest,IOException { String name = request.getParameter("fileName"); System.out.print("dddddddddd:" + name); // web绝对路径 String path = request.getSession().getServletContext().getRealPath("/"); String savePath = path + "upload"; // 设置为下载application/x-download response.setContentType("application/x-download"); // 即将下载的文件在服务器上的绝对路径 String filenamedownload = savePath + "/" + name; // 下载文件时显示的文件保存名称 String filenamedisplay = name; // 中文编码转换 filenamedisplay = URLEncoder.encode(filenamedisplay,"UTF-8"); response.addHeader("Content-Disposition","attachment;filename=" + filenamedisplay); try { java.io.OutputStream os = response.getOutputStream(); java.io.FileInputStream fis = new java.io.FileInputStream( filenamedownload); byte[] b = new byte[1024]; int i = 0; while ((i = fis.read(b)) > 0) { os.write(b,i); } fis.close(); os.flush(); os.close(); } catch (Exception e) { } } }
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持编程小技巧。
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