标签：enc imp catch tput servlet div version list cep
Upload
<form method="post" action="http://localhost:8080/thirdTry/uploadServlet"
enctype="multipart/form-data">
Profile Image: <input type="file" name="photo"> <br>
// upload.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Upload</title> </head> <body> <form method="post" action="http://localhost:8080/thirdTry/uploadServlet" enctype="multipart/form-data"> Username: <input type="text" name="username"/> <br> Profile Image: <input type="file" name="photo"> <br> <input type="submit" value="Submit"> </form> </body> </html>
JAR you need:
<dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.4</version> </dependency> <!-- https://mvnrepository.com/artifact/commons-fileupload/commons-fileupload --> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.2.1</version> </dependency>
ServletFileUpload class: Parse the uploaded data
FileItem class : represents every form item
UploadServlet.java
package com.truman.servlet; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileItemFactory; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; import javax.servlet.ServletException; import javax.servlet.ServletInputStream; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.File; import java.io.IOException; import java.util.List; public class UploadServlet extends HttpServlet { @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { // String username = req.getParameter("username"); //// System.out.println("Got Request."); // // ServletInputStream inputStream = req.getInputStream(); // // byte[] buffer = new byte[1024]; // int read = inputStream.read(buffer); // System.out.println(new String(buffer, 0, read)); // determine if the data uploaded is multipart/form-data if(ServletFileUpload.isMultipartContent(req)){ FileItemFactory fileItemFactory = new DiskFileItemFactory(); //ServletFileUpload is used to parse the data uploaded ServletFileUpload servletFileUpload = new ServletFileUpload(fileItemFactory); try { // get every form item List<FileItem> list = servletFileUpload.parseRequest(req); // determine every item : regular file or uploaded file for(FileItem fileItem : list){ if(fileItem.isFormField()){ //regular file System.out.println("attribute is : " + fileItem.getFieldName()); System.out.println("value is : " + fileItem.getString("UTF-8")); }else{ // the file uploaded System.out.println("attribute is : " + fileItem.getFieldName()); System.out.println("File name : " + fileItem.getName()); try { fileItem.write(new File("/Users/truman/Desktop/father.jpg")); } catch (Exception e) { e.printStackTrace(); } } } } catch (FileUploadException e) { e.printStackTrace(); } } } }
Download
DownloadServlet.java
package com.truman.servlet; import org.apache.commons.io.IOUtils; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; public class DownloadServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { // get the filename String downloadFilename = "nana.jpeg"; // get the context of the file through servletContext ServletContext servletContext = this.getServletContext(); // tell response type to client String mimeType = servletContext.getMimeType("/file/" + downloadFilename); resp.setContentType(mimeType); // tell client the file is to download, or the browser will just display it resp.setHeader("Content-Disposition", "attachment; filename=" + downloadFilename); // URLEncoder.encode("汉字.jpg","UTF-8") : if you use Chinese, use this to replace the filename // URLEncoder is used in Chrome and IE, but in Firefox, use Base64 InputStream resourceAsStream = servletContext.getResourceAsStream("/file/" + downloadFilename); // use IOUtils to read all the data and send to output OutputStream outputStream = resp.getOutputStream(); IOUtils.copy(resourceAsStream, outputStream); } }
标签：enc imp catch tput servlet div version list cep
原文地址：https://www.cnblogs.com/nedrain/p/13189895.html
