JAvaWeb実装アップロード+ダウンロードファイル
アップロードダウンロードはwebプロジェクトでよく見られるニーズであり、コードを上手に叩くことができる実現はweb開発者にとって不可欠である.
以下の簡単なアップロード:
jspページの実装:
以下の簡単なアップロード:
jspページの実装:
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib uri = "http://java.sun.com/jsp/jstl/core" prefix = "c" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'uploadfile.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<form action="<c:url value = '/UploadServlet1' />" method="post" enctype="multipart/form-data" >
：<input type = "text" name = "username">
：<input type = "file" name = "photo">
<input type = "submit" value=" ">
</form>
</body>
</html>servlet的实现:package cn.Lionel.servlet; 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; public class UploadServlet1 extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); // DiskFileItemFactory factory = new DiskFileItemFactory() ; // ServletFileUpload upload = new ServletFileUpload(factory); try { List<FileItem> list = upload.parseRequest(request); FileItem item1 = list.get(0); FileItem item2 = list.get(1); System.out.println(" ："+item1.getName()+"="+item1.getString("utf-8")); System.out.println(" :"); System.out.println("Content-Type"+item2.getContentType()); System.out.println("filename="+item2.getName()); System.out.println("size = "+item2.getSize()); item2.write(new File("d:\\1.jpg")); } catch (Exception e) { throw new RuntimeException() ; } } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }下面是设置了缓存文件夹+文件打散
jsp页面跟上面差不多：
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <%@ taglib uri = "http://java.sun.com/jsp/jstl/core" prefix = "c" %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>My JSP 'uploadfile.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> <h1>${msg }</h1> <form action="<c:url value = '/UploadServlet2' />" method="post" enctype="multipart/form-data" > ：<input type = "text" name = "username"> ：<input type = "file" name = "photo"> <input type = "submit" value=" "> </form> </body> </html>servlet的实现依赖commons.fileupload组件package cn.Lionel.servlet; import java.io.File; import java.io.IOException; 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.FileUploadBase; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; public class UploadServlet3 extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); // DiskFileItemFactory factory = new DiskFileItemFactory(100,new File("e:\\temp")); ServletFileUpload upload = new ServletFileUpload(factory); // //upload.setFileSizeMax(200*1024) ; // ：upload.setSizeMax(); try { List<FileItem> list = upload.parseRequest(request); FileItem item = list.get(1); String filename = item.getName(); // int index = filename.lastIndexOf("\\") ; if(index != -1) { filename = filename.substring(index+1); } int hashCode = filename.hashCode(); // hash String hex = Integer.toHexString(hashCode); String realPath = this.getServletContext().getRealPath( "WEB-INF/files"); File dirFile = new File(realPath + "/" + hex.charAt(0) + "/" + hex.charAt(1)); // dirFile.mkdirs(); String savename = uuid()+"_"+filename; File destFile = new File(dirFile,savename); item.write(destFile); }catch (FileUploadException e) { if(e instanceof FileUploadBase.FileSizeLimitExceededException) { request.setAttribute("msg", " 200KiB!") ; request.getRequestDispatcher("/uploadfile2.jsp").forward(request, response) ; return ; } } catch (Exception e) { throw new RuntimeException(); } } private String uuid() { return UUID.randomUUID().toString().replace("-", "").toUpperCase(); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
アップロードの話が終わったら、ダウンロードしたと言います.
この事前にcommons.ioコンポーネントに依存し、servletに直接アクセスしてダウンロードを実現します.ダウンロードするファイルは、自分のプロジェクトに存在するファイルを変更する必要があります.package cn.Lionel.servlet; import java.io.FileInputStream; import java.io.IOException; import java.net.URLEncoder; import javax.servlet.ServletException; import javax.servlet.ServletOutputStream; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.io.IOUtils; import sun.misc.BASE64Encoder; public class DownloadServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset = utf-8"); String filename = "E:\\KuGou\\ - .mp3"; // // ！ //String dname = new String(" .mp3".getBytes("utf-8"), "iso-8859-1"); // ！ String dname = filenameEncoding(" .mp3",request); String contentType = this.getServletContext().getMimeType(filename); String contentDisposition = "attachment;filename="+dname; response.setHeader("Content-Type", contentType + ""); response.setHeader("Content-Disposition", contentDisposition); FileInputStream input = new FileInputStream(filename); ServletOutputStream out = response.getOutputStream(); IOUtils.copy(input, out); input.close(); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } public static String filenameEncoding(String filename, HttpServletRequest request) throws IOException { String agent = request.getHeader("User-Agent"); // if (agent.contains("Firefox")) { BASE64Encoder base64Encoder = new BASE64Encoder(); filename = "=?utf-8?B?" + base64Encoder.encode(filename.getBytes("utf-8")) + "?="; } else if(agent.contains("MSIE")) { filename = URLEncoder.encode(filename, "utf-8"); } else { filename = URLEncoder.encode(filename, "utf-8"); } return filename; } }
能力に限りがある.ブログを書くのは自分が忘れないようにするためだけで、検索しやすいので、間違いがあれば、指摘してください.