上传：
Servlet2.5
1 <form action="${pageContext.request.contextPath }/uploadServlet" method="POST" enctype="multipart/form-data"> 2 姓名:<input type="text" name="name"/> <br> 3 年龄:<input type="text" name="age"/> <br> 4 照片:<input type="file" name="photo"/> <br> 5 <input type="submit" value="注册"/> 6 </form>
1 package com.lijie.servlets; 2 3 import java.io.File; 4 import java.io.FileOutputStream; 5 import java.io.IOException; 6 import java.io.InputStream; 7 import java.io.OutputStream; 8 import java.io.PrintWriter; 9 import java.text.SimpleDateFormat; 10 import java.util.Calendar; 11 import java.util.Date; 12 import java.util.Iterator; 13 import java.util.List; 14 15 import javax.servlet.ServletException; 16 import javax.servlet.ServletInputStream; 17 import javax.servlet.http.HttpServlet; 18 import javax.servlet.http.HttpServletRequest; 19 import javax.servlet.http.HttpServletResponse; 20 21 import org.apache.commons.fileupload.FileItem; 22 import org.apache.commons.fileupload.FileUploadException; 23 import org.apache.commons.fileupload.disk.DiskFileItemFactory; 24 import org.apache.commons.fileupload.servlet.ServletFileUpload; 25 26 27 public class UploadServlet extends HttpServlet { 28 private static final long serialVersionUID = 1L; 29 30 31 protected void doPost(HttpServletRequest request, HttpServletResponse response) 32 throws ServletException, IOException { 33 34 /*ServletInputStream is = request.getInputStream(); 35 response.setContentType("text/html;charset=UTF-8"); 36 37 PrintWriter out = response.getWriter(); 38 int len = -1; 39 byte[] buffer = new byte[1024]; 40 while((len = is.read(buffer))!=-1){ 41 String str = new String(buffer); 42 out.println(str); 43 } 44 is.close();*/ 45 46 System.out.println("===========执行上传==========="); 47 //解析请求 48 try { 49 //判断请求类型 50 boolean isMultipart = ServletFileUpload.isMultipartContent(request); 51 if(!isMultipart){ 52 throw new RuntimeException("当前请求不支持文件上传!"); 53 } 54 //创建FileItem工厂 55 DiskFileItemFactory factory = new DiskFileItemFactory(); 56 //设置使用临时文件的边界值(大于该值，上传文件会保存在临时文件中，小于等于该值，写入内存。单位:字节) 57 //本例设置为1M(1M=1024KB 1KB=1024B) 58 factory.setSizeThreshold(1024 * 1024 * 1); 59 //设置临时文件(上传完毕后要删除temp文件夹下的文件) 60 File tempFile = new File(this.getServletContext().getRealPath("/temp")); 61 factory.setRepository(tempFile); 62 63 //创建文件上传核心组件 64 ServletFileUpload upload = new ServletFileUpload(factory); 65 //防止文件名乱码 66 upload.setHeaderEncoding("UTF-8"); 67 //限制单次上传的文件大小边界值 68 upload.setFileSizeMax(1024*1024*2); 69 //限制多文件上传时的大小总和(这里是单文件，所有不起作用) 70 upload.setSizeMax(1024*1024*5); 71 //解析请求获取所有的Item 72 List<FileItem> items = upload.parseRequest(request); 73 //遍历Item 74 Iterator<FileItem> iter = items.iterator(); 75 while (iter.hasNext()) { 76 FileItem item = iter.next(); 77 if (item.isFormField()) { 78 //普通表单项 79 String fieldName = item.getFieldName(); 80 String fieldValue = item.getString("UTF-8"); 81 System.out.println(fieldName+" = "+fieldValue); 82 } else { 83 //文件上传表单项 84 String fileName = item.getName(); 85 //防止上传同名文件 86 fileName = System.currentTimeMillis() + fileName; 87 //输入流 88 InputStream is = item.getInputStream(); 89 String path = this.getServletContext().getRealPath("/images"); 90 91 92 //由于windows系统一个文件夹下最多有65535个文件 93 //所有对images文件夹下再进行分文件夹进行存储上传的文件 94 //1.按照yyyyMMdd的日期存放 95 /*Date now = new Date(); 96 SimpleDateFormat format = new SimpleDateFormat("yyyyMMdd"); 97 String nowTime = format.format(now); 98 path = path + "/" + nowTime; 99 System.out.println("文件在服务器地址:" + path); 100 File dirFile = new File(path); 101 if(!dirFile.exists()){ 102 dirFile.mkdir(); 103 }*/ 104 //2.按照年月日的格式分多级目录存放 105 Calendar now = Calendar.getInstance(); 106 int year = now.get(Calendar.YEAR); 107 int month = now.get(Calendar.MONTH) + 1; 108 int day = now.get(Calendar.DAY_OF_MONTH); 109 path = path + "/" + year + "/" + month + "/" + day; 110 File dirFile = new File(path); 111 if(!dirFile.exists()){ 112 dirFile.mkdirs(); 113 } 114 //输出流 115 File file = new File(path ,fileName); 116 OutputStream os = new FileOutputStream(file); 117 int len = -1; 118 byte[] buffer = new byte[1024]; 119 while((len=is.read(buffer)) != -1){ 120 os.write(buffer,0, len); 121 } 122 os.flush(); 123 os.close(); 124 is.close(); 125 //删除临时文件夹的文件 126 item.delete(); 127 } 128 } 129 System.out.println("===========上传成功==========="); 130 } catch (FileUploadException e) { 131 // TODO Auto-generated catch block 132 e.printStackTrace(); 133 } 134 } 135 }
Servlet3.0
1 <form action="${pageContext.request.contextPath }/uploadServlet" method="POST" enctype="multipart/form-data"> 2 文件:<input type="file" name="file"><br> 3 <input type="submit" value="上传"> 4 </form>
1 package com.lijie.servlet; 2 3 import java.io.IOException; 4 import javax.servlet.ServletException; 5 import javax.servlet.annotation.MultipartConfig; 6 import javax.servlet.annotation.WebServlet; 7 import javax.servlet.http.HttpServlet; 8 import javax.servlet.http.HttpServletRequest; 9 import javax.servlet.http.HttpServletResponse; 10 import javax.servlet.http.Part; 11 12 @WebServlet("/uploadServlet") 13 @MultipartConfig 14 public class UploadServlet extends HttpServlet { 15 16 protected void doPost(HttpServletRequest request, HttpServletResponse response) 17 throws ServletException, IOException { 18 19 String path = this.getServletContext().getRealPath("/images"); 20 Part part = request.getPart("file"); 21 22 String header = part.getHeader("Content-Disposition"); 23 int indexOf = header.lastIndexOf("="); 24 String fileName = header.substring(indexOf+2, header.length()-1); 25 part.write(path+"/"+fileName); 26 } 27 28 }
下载：
1 <a href="${pageContext.request.contextPath }/downloadServlet">跑车</a> <br>
1 package com.lijie.servlets;
2
3 import java.io.IOException;
4 import java.io.InputStream;
5
6 import javax.servlet.ServletException;
7 import javax.servlet.ServletOutputStream;
8 import javax.servlet.http.HttpServlet;
9 import javax.servlet.http.HttpServletRequest;
10 import javax.servlet.http.HttpServletResponse;
11
12 public class DownloadServlet extends HttpServlet {
13 protected void doGet(HttpServletRequest request, HttpServletResponse response)
14 throws ServletException, IOException {
15
16 String fileName = "超跑.jpg";
17
18 // 打散：按当前的字符编码进行打散
19 byte[] bytes = fileName.getBytes("UTF-8");
20 // 组装：按目标字符编码进行组装
21 fileName = new String(bytes, "ISO8859-1");
22
23 // 修改响应的头部属性content-disposition值为attachment
24 response.setHeader("content-disposition", "attachment;filename=" + fileName);
25
26 // 获取连接服务端资源文件的输入流
27 InputStream is = this.getServletContext().getResourceAsStream("/resources/aaa.jpg");
28 // 获取输出流
29 ServletOutputStream os = response.getOutputStream();
30 // 将输入流中的数据写入到输出流中
31 int len = -1;
32 byte[] buf = new byte[1024];
33 while((len = is.read(buf)) != -1) {
34 os.write(buf, 0, len);
35 }
36 // 关闭流
37 os.close();
38 is.close();
39 }
40 }
