案例:用户的注册和登录功能

  1 package com.imooc.web.servlet;
  2 
  3 import java.io.FileOutputStream;
  4 import java.io.IOException;
  5 import java.io.InputStream;
  6 import java.io.OutputStream;
  7 import java.util.HashMap;
  8 import java.util.List;
  9 import java.util.Map;
 10 
 11 import javax.servlet.ServletException;
 12 import javax.servlet.annotation.WebServlet;
 13 import javax.servlet.http.HttpServlet;
 14 import javax.servlet.http.HttpServletRequest;
 15 import javax.servlet.http.HttpServletResponse;
 16 
 17 import org.apache.commons.fileupload.FileItem;
 18 import org.apache.commons.fileupload.FileUploadException;
 19 import org.apache.commons.fileupload.disk.DiskFileItemFactory;
 20 import org.apache.commons.fileupload.servlet.ServletFileUpload;
 21 
 22 import com.imooc.domain.User;
 23 import com.imooc.service.UserService;
 24 import com.imooc.service.impl.UserServiceImpl;
 25 import com.imooc.utils.UploadUtils;
 26 
 27 @WebServlet("/RegistServlet")
 28 public class RegistServlet extends HttpServlet {
 29     private static final long serialVersionUID = 1L;
 30 
 31     protected void doGet(HttpServletRequest request, HttpServletResponse response)
 32             throws ServletException, IOException {
 33         // 接收数据
 34         // 创建Map集合用于保存数据:
 35         Map<String,String> map = new HashMap<String,String>();
 36         // 文件上传的代码:
 37         // 1.创建磁盘文件项工厂
 38         DiskFileItemFactory diskFileItemFactory = new DiskFileItemFactory();
 39         // 2.创建核心解析类
 40         ServletFileUpload fileUpload = new ServletFileUpload(diskFileItemFactory);
 41         // 3.解析请求对象,将请求分成几个部分(FileItem)
 42         try {
 43             List<FileItem> list = fileUpload.parseRequest(request);
 44             // 4.遍历集合获得每个部分的对象
 45             for (FileItem fileItem : list) {
 46                 // 判断是普通项还是文件上传项
 47                 if (fileItem.isFormField()) {
 48                     // 普通项--用户名(username--输入的值) 密码 确认密码
 49                     // 获得普通项的名称:
 50                     String name = fileItem.getFieldName();
 51                     // 获得普通项的值:
 52                     String value = fileItem.getString("UTF-8");
 53                     // 保存数据:
 54                     map.put(name, value);
 55                 } else {
 56                     // 文件上传项
 57                     // 获得文件的名称:
 58                     String fileName = fileItem.getName();
 59                     // 获得唯一文件名:
 60                     String uuidFileName = UploadUtils.getUuidFileName(fileName);
 61                     // 获得文件的输入流:
 62                     InputStream is = fileItem.getInputStream();
 63                     // 需要将文件写入到服务器的某个路径即可:
 64                     String path = getServletContext().getRealPath("/upload");
 65                     System.out.println(path);// D:/xxx/ddd/
 66                     // 显示图片<img src="/regist_login/upload/a.jpg">
 67                     // 创建输出流 与 输入流进行对接:
 68                     String url = path + "\" + uuidFileName;
 69                     map.put("path", request.getContextPath()+"/upload/"+uuidFileName);
 70                     OutputStream os = new FileOutputStream(url);
 71                     int len = 0;
 72                     byte[] b = new byte[1024];
 73                     while ((len = is.read(b)) != -1) {
 74                         os.write(b, 0, len);
 75                     }
 76                     is.close();
 77                     os.close();
 78                 }
 79             }
 80         } catch (FileUploadException e) {
 81             // TODO Auto-generated catch block
 82             e.printStackTrace();
 83         }
 84 
 85         // 封装数据
 86         User user = new User();
 87         user.setUsername(map.get("username"));
 88         user.setPassword(map.get("password"));
 89         
 90         user.setPath(map.get("path"));
 91         System.out.println(user);
 92         // 处理数据
 93         UserService userService = new UserServiceImpl();
 94         // 从ServletContext域中获取用户的集合即可
 95         List<User> userList = (List<User>) getServletContext().getAttribute("userList");
 96         userService.regist(userList, user);
 97         System.out.println(userList);
 98         // 显示处理结果
 99         response.sendRedirect(request.getContextPath() + "/login.jsp");
100     }
101 
102     protected void doPost(HttpServletRequest request, HttpServletResponse response)
103             throws ServletException, IOException {
104         doGet(request, response);
105     }
106 
107 }