java - jsp表单文本+文件处理
问题描述
bookReg.jsp
<%@page import="classes.BooksDTO"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional"
"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>
<link type="text/css" href="css/mainStyle.css">
</head>
<body>
<%
//D:\Hayden\учеба\джава\JavaBigData\readers\WebContent\img - folder directory
%>
<form action="bookRegProc.jsp" method="post" enctype="multipart/form-data">
Title <input type="text" name="title"> <br>
Plot <textarea rows="30" cols="40" name="plot"></textarea> <br>
<input type="hidden" name="rating" value="0"> <br>
Author <input type="text" name="author"> <br>
Publisher <input type="text" name="publisher"> <br>
Genre <input type="text" name="genre"> <br>
Publication date <input type="text" name="date"> <br>
Cover <input type="file" name="cover" size="50"> <br>
<input type="submit" value="Register"> <br>
</form>
</body>
</html>
bookRegProc.jsp
<%@page import="classes.Uploader"%>
<%@page import="org.apache.commons.fileupload.FileItem"%>
<%@page import="java.util.Iterator"%>
<%@page import="java.util.List"%>
<%@page import="org.apache.commons.fileupload.servlet.ServletFileUpload"%>
<%@page import="org.apache.commons.fileupload.disk.DiskFileItemFactory"%>
<%@page import="java.io.File"%>
<%@page import="classes.BooksDTO"%>
<%@page import="classes.BooksDAO"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<%
Uploader upload = new Uploader();
upload.doPost(request, response);
%>
</body>
</html>
上传者.java
package classes;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Paths;
import java.util.Iterator;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;
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;
public class Uploader extends HttpServlet {
BooksDTO dto = null;
BooksDAO dao = new BooksDAO();
String title = null;
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String title = request.getParameter("title"); // Retrieves <input type="text" name="description">
String plot = request.getParameter("plot");
String rating = request.getParameter("rating");
String author = request.getParameter("author");
String publisher = request.getParameter("publisher");
String genre = request.getParameter("genre");
String date = request.getParameter("date");
Part filePart = request.getPart("file"); // Retrieves <input type="file" name="file">
/*String fileName = title;
InputStream fileContent = filePart.getInputStream();*/
// ... (do your job here)
//DTO process
BooksDTO dto = new BooksDTO();
BooksDAO dao = new BooksDAO();
dto.setTitle(title);
dto.setAuthor(author);
dto.setDate(date);
dto.setGenre(genre);
dto.setPlot(plot);
dto.setPublisher(publisher);
dto.setRating(rating);
try {
dao.insert(dto);
//this inserts all the parameters into database
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//File process
File file;
int maxFileSize = 5000 * 1024;
int maxMemSize = 5000 * 1024;
String filePath = "D:/Hayden/Eclipse workspace/bigdata/readers/WebContent/img/";
DiskFileItemFactory factory = new DiskFileItemFactory();
factory.setSizeThreshold(maxMemSize);
factory.setRepository(new File("C:/temp"));
ServletFileUpload upload = new ServletFileUpload(factory);
upload.setSizeMax(maxFileSize);
try {
FileItem fi = (FileItem) filePart;
if(!fi.isFormField()) {
file = new File(filePath + dto.getTitle() + ".jpg");
fi.write(file);
}
}catch(Exception ex) {
System.out.println(ex);
}
}
}
我想传递文本参数bookReg.jsp
以将其注册到我的数据库中。我检查了插入数据库的方法完全正常。但在doPost
方法中Uploader.java
,request.getParameter
传递null
给每个字符串。我搜索了如何将文本传递给 servlet 好几天,最后我按照以下说明进行操作:如何使用 JSP/Servlet 将文件上传到服务器?(第一个答案)
但它仍然只传递 null 。正如我所写的,在 jsp 和 java 类中使用 request.getParameter 传递参数有什么区别?
即使我遵循了我遵循的页面中第一个答案的说明,是什么导致了同样的问题?(我正在使用tomcat 8.5和eclipse氧气)
解决方案
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