java - 将部分转换为字符串

Question

package servlet;


import java.io.File;
import java.util.List;
import java.util.Iterator;
import java.util.*;
import java.io.*;



import java.io.IOException;
import java.io.PrintWriter;
import java.security.Security;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Properties;
import java.util.Random;

import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet; 
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession; 
import javax.servlet.http.Part;

import database.DBAO;
import model.Login;



  /**
  * Servlet implementation class SignupServlet
  */
 @MultipartConfig(fileSizeThreshold=1024*1024*2, // 2MB
 maxFileSize=1024*1024*10,      // 10MB
 maxRequestSize=1024*1024*50)
 @WebServlet("/SignupServlet")
 public class SignupServlet extends HttpServlet{
 private static final long serialVersionUID = 1L;
 private static final String SAVE_DIR="images";
   /**
 * @see HttpServlet#HttpServlet()
 */

public SignupServlet() {
    super();    
}

/**
 * @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 doPost(HttpServletRequest request, HttpServletResponse response) 
        throws ServletException, IOException {

        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();

        String savePath = "C:" + File.separator + SAVE_DIR;
        File fileSaveDir=new File(savePath);
        if(!fileSaveDir.exists()){
              fileSaveDir.mkdir();
          }



        Random rand = new Random();
        int num = rand.nextInt(900000) + 100000;
        String Password = Integer.toString(num);

        String Name = request.getParameter("name");
        String Email = request.getParameter("email");
        String UserType = request.getParameter("usertype");
        String strDOB = request.getParameter("dob");
        String Gender = request.getParameter("gender");
        Part part = request.getPart("file");
        String fileName = part.toString();

        String filePath = savePath + File.separator + fileName;
        part.write(savePath + File.separator + fileName);



        java.sql.Date d;

        SimpleDateFormat sdf;
        sdf = new SimpleDateFormat("yyyy-MM-dd");
        java.util.Date d2 = null;

        try{
            d2 = sdf.parse(strDOB);
        } catch (ParseException e1) {
            e1.printStackTrace();
        }

        d = new java.sql.Date(d2.getTime());

        DBAO dbao = null;
        Login login = null;




        try {      


            // configuration for mail
            Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());
            Properties props = System.getProperties();
                String host = "smtp.gmail.com";
                String port = "465";
                String fromEmail = "lookeverybodysg@gmail.com";
                String username = "lookeverybodysg";
                String password = "catdog1234";

                props.put("mail.smtp.user", fromEmail);
                props.put("mail.smtp.host", host);
                props.put("mail.smtp.starttls.enable","true");
                props.put("mail.smtp.debug", "true");
                props.put("mail.smtp.auth", "true");
                props.put("mail.smtp.port", port);
                props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
                props.put("mail.smtp.socketFactory.port", port);
                props.put("mail.smtp.socketFactory.fallback", "false");


                Session mailSession = Session.getDefaultInstance(props,  new javax.mail.Authenticator() {

                    protected PasswordAuthentication getPasswordAuthentication() {
                        return new PasswordAuthentication("lookeverybodysg", "catdog1234"); // username and password
                    }
                });
                mailSession.setDebug(true);

                Message mailMessage = new MimeMessage(mailSession);


            dbao = new DBAO();

                if (dbao.emailExists(Email)){
                    request.setAttribute("Name", Name);
                    request.setAttribute("Email", Email);
                    request.setAttribute("UserType", UserType);
                    request.setAttribute("strDOB", strDOB);
                    request.setAttribute("Gender", Gender);
                    request.setAttribute("Pic", filePath);


                    response.setContentType("text/html");
                    out.println("<script type=\"text/javascript\">"); 
                    out.println("alert('The email you have used has already been regietered.');");
                    out.println("location='Login.jsp#signup';");
                    out.println("</script>"); 
                    return;
                }else{
                    login = new Login();
                    login.setName(Name);
                    login.setEmail(Email);
                    login.setPassword(Password);
                    login.setUserType(UserType);
                    login.setDOB(d);
                    login.setGender(Gender);
                    login.setPic(filePath);

                    boolean isUserSaved = dbao.saveNewUser(login);

                if (isUserSaved){
                    mailMessage.setFrom(new InternetAddress("lookeverybodysg@gmail.com"));
                    mailMessage.setRecipient(Message.RecipientType.TO, new InternetAddress(Email));
                    mailMessage.setSubject("Thank You for signing up to LookEveryBody!");
                    mailMessage.setContent("Email :" + Email + "<br> Password :" + Password, "text/html");

                    Transport transport = mailSession.getTransport("smtps");
                    transport.connect (host, 465, username, password);

                    transport.send(mailMessage);

                    response.setContentType("text/html");
                    out.println("<script type=\"text/javascript\">"); 
                    out.println("alert('Your accout has been successfully created, please go to your email to get your password.');");
                    out.println("location='Login.jsp';");
                    out.println("</script>"); 
                    return;
                }

            }

        }catch(Exception e)
        {
            e.printStackTrace();
        }
}
}

我能够将路径存储到MySQL中，但图像文件的名称很奇怪，示例在链接中:SQL

我知道该错误特别出现在以下行:

Part part = request.getPart("file");
String fileName = part.toString();

非常感谢任何帮助，因为我现在正在进行我的最后一年的项目。

Answer 1

由于 Part 类中的 toString() 方法，文件名很奇怪。此类使用 Object 类的默认实现，该类打印 jvm 特定的实例 ID。

您的 Part 类实现可能具有返回文件名的公共(public)方法。试试这个:

String fileName = part.getSubmittedFileName(();

而不是:

String fileName = part.toString();

(可选)您始终可以获取人类可读的fileName，将附加属性引入请求。

还考虑自己生成文件名 - 例如，获取随机UUID作为fileName。 UUID 文件名生成将有助于防止文件系统中的名称冲突(如果用户提交两个具有相同名称的不同文件怎么办？)