上傳檔案至伺服器Demo
阿新 • • 發佈：2019-01-06
上傳檔案至伺服器，需要用到一個開源工具，file-upload.jar
在webcontent下建立一個新的資料夾upload
String uploadPath = getServletContext().getRealPath("upload");//上傳的檔案的儲存路徑
Servlet檔案
package main.web; import java.io.File; import java.io.IOException; import java.util.List; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; 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.FileUploadException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; /**上傳檔案至伺服器 * Servlet implementation class FileUploadServlet */ @WebServlet("/FileUploadServlet") public class FileUploadServlet extends HttpServlet { private static final long serialVersionUID = 1L; private String uploadPath = ""; /** * @see HttpServlet#HttpServlet() */ public FileUploadServlet() { super(); // TODO Auto-generated constructor stub } public void init(){ uploadPath = getServletContext().getRealPath("upload"); System.out.println(uploadPath); } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { System.out.println("upload file...."); request.setCharacterEncoding("UTF-8"); // Check that we have a file upload request boolean isMultipart = ServletFileUpload.isMultipartContent(request); if(!isMultipart){ return; } //直接用getParameter()返回null //String filePath = request.getParameter("filepath"); //System.out.println(filePath); // ①Create a factory for disk-based file items DiskFileItemFactory factory = new DiskFileItemFactory(); // Configure a repository (to ensure a secure temp location is used) ServletContext servletContext = this.getServletConfig().getServletContext(); File repository = (File) servletContext.getAttribute("filepath"); factory.setRepository(repository); // ②Create a new file upload handler ServletFileUpload upload = new ServletFileUpload(factory); List<FileItem> items =null; // ③Parse the request,一個fileitem物件對應一個form表單域 try { items = upload.parseRequest(request); } catch (FileUploadException e) { // TODO Auto-generated catch block e.printStackTrace(); } //遍歷表單域 for(FileItem item :items){ if(item.isFormField()){//普通表單域 String value = item.getString("UTF-8"); String fieledName = item.getFieldName();//表單的name屬性 System.out.println(value+" "+fieledName); }else{//上傳檔案域 String value = item.getName(); String fieledName = item.getFieldName();//表單name屬性 System.out.println(value+" "+fieledName); try { item.write(new File(uploadPath+File.separator+item.getName())); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } } } }
jsp檔案
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>Insert title here</title> </head> <body> <form action="fileupload" method="post" enctype="multipart/form-data"> 使用者名稱:<input type="text" name="username"/> <input type="file" name="filepath"/> <input type="submit" value="上傳"> </form> </body> </html>