項目結構
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src com servletdemo DownloadServlet.java ShowServlet.java UploadServlet.java WebContent jsp servlet download.html fileupload.jsp input.jsp WEB-INF lib commons-fileupload-1.3.1.jar commons-io-2.4.jar |
1.簡單實例
ShowServlet.java
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package com.servletdemo;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * Servlet implementation class ShowServlet */@WebServlet("/ShowServlet")public class ShowServlet extends HttpServlet { private static final long serialVersionUID = 1L; PrintWriter pw=null; /** * @see HttpServlet#HttpServlet() */ public ShowServlet() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub this.doPost(request, response); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub request.setCharacterEncoding("gb2312"); response.setContentType("text/html;charset=gb2312"); pw=response.getWriter(); String name=request.getParameter("username"); String password=request.getParameter("password"); pw.println("user name:" + name); pw.println("<br>"); pw.println("user password:" + password); }} |
input.jsp
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<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%><!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=ISO-8859-1"><title>servlet demo</title></head><body><form action="<%=request.getContextPath()%>/ShowServlet"> <table> <tr> <td>name</td> <td><input type="text" name="username"></td> </tr> <tr> <td>password</td> <td><input type="text" name="password"></td> </tr> <tr> <td><input type="submit" value="login"></td> <td><input type="reset" value="cancel"></td> </tr> </table> </form></body></html> |
2.文件上傳實例
UploadServlet.java
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package com.servletdemo;import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.PrintWriter; import java.text.DateFormat; import java.util.Date; import java.util.List; import java.util.UUID; 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.ProgressListener; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload;/** * Servlet implementation class UploadServlet */@WebServlet("/servlet/UploadServlet")public class UploadServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public UploadServlet() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub //設置編碼 request.setCharacterEncoding("UTF-8"); response.setContentType("text/html;charset=UTF-8"); PrintWriter pw = response.getWriter(); try { //設置系統環境 DiskFileItemFactory factory = new DiskFileItemFactory(); //文件存儲的路徑 String storePath = getServletContext().getRealPath("/WEB-INF/files"); //判斷傳輸方式 form enctype=multipart/form-data boolean isMultipart = ServletFileUpload.isMultipartContent(request); if(!isMultipart) { pw.write("傳輸方式有錯誤！"); return; } ServletFileUpload upload = new ServletFileUpload(factory); upload.setFileSizeMax(4*1024*1024);//設置單個文件大小不能超過4M upload.setSizeMax(4*1024*1024);//設置總文件上傳大小不能超過6M //監聽上傳進度 upload.setProgressListener(new ProgressListener() { //pBytesRead：當前以讀取到的字節數 //pContentLength：文件的長度 //pItems:第幾項 public void update(long pBytesRead, long pContentLength, int pItems) { System.out.println("已讀去文件字節 :"+pBytesRead+" 文件總長度："+pContentLength+" 第"+pItems+"項"); } }); //解析 List<FileItem> items = upload.parseRequest(request); for(FileItem item: items) { if(item.isFormField())//普通字段，表單提交過來的 { String name = item.getFieldName(); String value = item.getString("UTF-8"); System.out.println(name+"=="+value); }else { // String mimeType = item.getContentType(); 獲取上傳文件類型 // if(mimeType.startsWith("image")){ InputStream in =item.getInputStream(); String fileName = item.getName(); if(fileName==null || "".equals(fileName.trim())) { continue; } fileName = fileName.substring(fileName.lastIndexOf("\\")+1); fileName = UUID.randomUUID()+"_"+fileName; //按日期來建文件夾 String newStorePath = makeStorePath(storePath); String storeFile = newStorePath+"\\"+fileName; OutputStream out = new FileOutputStream(storeFile); byte[] b = new byte[1024]; int len = -1; while((len = in.read(b))!=-1) { out.write(b,0,len); } in.close(); out.close(); item.delete();//刪除臨時文件 } } // } }catch(org.apache.commons.fileupload.FileUploadBase.FileSizeLimitExceededException e){ //單個文件超出異常 pw.write("單個文件不能超過4M"); }catch(org.apache.commons.fileupload.FileUploadBase.SizeLimitExceededException e){ //總文件超出異常 pw.write("總文件不能超過6M"); }catch (FileUploadException e) { e.printStackTrace(); } } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub doGet(request, response); } private String makeStorePath(String storePath) { Date date = new Date(); DateFormat df = DateFormat.getDateInstance(DateFormat.MEDIUM); String s = df.format(date); String path = storePath+"\\"+s; File file = new File(path); if(!file.exists()) { file.mkdirs();//創建多級目錄，mkdir只創建一級目錄 } return path; } private String makeStorePath2(String storePath, String fileName) { int hashCode = fileName.hashCode(); int dir1 = hashCode & 0xf;// 0000~1111：整數0~15共16個 int dir2 = (hashCode & 0xf0) >> 4;// 0000~1111：整數0~15共16個 String path = storePath + "\\" + dir1 + "\\" + dir2; // WEB-INF/files/1/12 File file = new File(path); if (!file.exists()) file.mkdirs(); return path; } } |
fileupload.jsp
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<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%><% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %><!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=ISO-8859-1"><title>Upload File Demo</title></head><body><form action="${pageContext.request.contextPath}/servlet/UploadServlet" method="post" enctype="multipart/form-data"> user name<input type="text" name="username"/> <br/> <input type="file" name="f1"/><br/> <input type="file" name="f2"/><br/> <input type="submit" value="save"/> </form></body></html> |
3.文件下載實例
DownloadServlet.java
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package com.servletdemo;import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.OutputStream; import java.io.PrintWriter; import java.net.URLEncoder;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 javax.servlet.ServletResponse; /** * Servlet implementation class DownloadServlet */@WebServlet("/DownloadServlet")public class DownloadServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public DownloadServlet() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub download1(response); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub doGet(request, response); } public void download1(HttpServletResponse response) throws IOException{ //獲取所要下載文件的路徑 String path = this.getServletContext().getRealPath("/files/web配置.xml"); String realPath = path.substring(path.lastIndexOf("\\")+1); //告訴瀏覽器是以下載的方法獲取到資源 //告訴瀏覽器以此種編碼來解析URLEncoder.encode(realPath, "utf-8")) response.setHeader("content-disposition","attachment; filename="+URLEncoder.encode(realPath, "utf-8")); //獲取到所下載的資源 FileInputStream fis = new FileInputStream(path); int len = 0; byte [] buf = new byte[1024]; while((len=fis.read(buf))!=-1){ response.getOutputStream().write(buf,0,len); } }} |
download.html
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<!DOCTYPE html><html><head><meta charset="ISO-8859-1"><title>Download Demo</title><meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="this is my page"> <meta http-equiv="content-type" content="text/html; charset=UTF-8"></head><body><a href = "/JavabeanDemo/DownloadServlet">download</a></body></html> |
以上這篇Java Servlet簡單實例分享(文件上傳下載demo)就是小編分享給大家的全部內容了，希望能給大家一個參考，也希望大家多多支持服務器之家。
