我正在尝试从提交的表单中获取值，我尝试了我可以在互联网上找到的所有内容，但是当我使用request.getParameter（）时它仍然会返回null，它只返回“bulkname”的值而所有其他变量都给我null，我不知道为什么。
此表单应该从用户获取值并将其提交给servlet，因此我可以将值和文件插入到数据库中。
这是我的代码。
bulkCheckServlet.java
/*
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* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package source;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.time.LocalDateTime;
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.Part;
/**
*
* @author Farouk
*/
@WebServlet(name = "bulkCheckServlet", urlPatterns = {"/bulkCheckServlet"})
@MultipartConfig
public class bulkCheckServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String bulkname = request.getParameter("bulkname");
String quota = request.getParameter("quota");//Integer.parseInt(request.getParameter("quota"));
System.out.println(quota);
String provider = request.getParameter("provider");
InputStream inputStream = null; // input stream of the upload file
// obtains the upload file part in this multipart request
Part filePart = request.getPart("file");
if (filePart != null) {
// prints out some information for debugging
System.out.println(filePart.getName());
System.out.println(filePart.getSize());
System.out.println(filePart.getContentType());
// obtains input stream of the upload file
inputStream = filePart.getInputStream();
}
Connection conn = null; // connection to the database
String message = null; // message will be sent back to client
try {
// connects to the database
DriverManager.registerDriver(new com.mysql.jdbc.Driver());
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/smsglobal", "root", "123456789");
// constructs SQL statement
String sql = "INSERT INTO smsbulk (id,quota,provider,bulkname,date,file) values (1,?,?,?,?,?);";
PreparedStatement statement = conn.prepareStatement(sql);
statement.setString(1, quota);
statement.setString(2, provider);
statement.setString(3, bulkname);
statement.setString(4, LocalDateTime.now().toString());
System.out.println(sql);
if (inputStream != null) {
// fetches input stream of the upload file for the blob column
statement.setBlob(5, inputStream);
}
// sends the statement to the database server
int row = statement.executeUpdate();
if (row > 0) {
message = "File uploaded and saved into database";
}
} catch (SQLException ex) {
message = "ERROR: " + ex.getMessage();
ex.printStackTrace();
} finally {
if (conn != null) {
// closes the database connection
try {
conn.close();
} catch (SQLException ex) {
ex.printStackTrace();
}
}
// sets the message in request scope
request.setAttribute("Message", message);
// forwards to the message page
getServletContext().getRequestDispatcher("/Campaign.jsp").forward(request, response);
}
}
/**
* Handles the HTTP <code>POST</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
test.jsp的
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Test</title>
</head>
<body>
<form action="bulkCheckServlet" method="post" enctype="multipart/form-data">
Provider
<br/>
<input type="text" id="provider" name="provider"/>
<br/>
<br/>
Bulk Name
<br/>
<input type="text" name="bulkname" id="bulkname"/>
<br/>
<br/>
Quota
<br/>
<input type="text" name="quota" id="quota"/>
<br/>
<br/>
File
<br/>
<input type="file" name="file" id="file"/>
<br/>
<input type="submit" value="Submit" />
<br/>
</form>
</body>
</html>
答案 0 :(得分：1)
使用以下代码替换您的servlet。可以完全帮助您。
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package source;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.time.LocalDateTime;
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.Part;
/**
*
* @author Farouk
*/
@WebServlet(name = "bulkCheckServlet", urlPatterns = {"/bulkCheckServlet"})
@MultipartConfig
public class bulkCheckServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String bulkname = request.getParameter("bulkname");
String quota = request.getParameter("quota");//Integer.parseInt(request.getParameter("quota"));
System.out.println(quota);
String provider = request.getParameter("provider");
InputStream inputStream = null; // input stream of the upload file
// obtains the upload file part in this multipart request
Part filePart = request.getPart("file");
if (filePart != null) {
// prints out some information for debugging
System.out.println(filePart.getName());
System.out.println(filePart.getSize());
System.out.println(filePart.getContentType());
// obtains input stream of the upload file
inputStream = filePart.getInputStream();
}
Connection conn = null; // connection to the database
String message = null; // message will be sent back to client
try {
// connects to the database
DriverManager.registerDriver(new com.mysql.jdbc.Driver());
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/smsglobal", "root", "0168308330");
// constructs SQL statement
String sql = "INSERT INTO smsbulk (id,quota,provider,bulkname,date,file) values (?,?,?,?,?,?);";
PreparedStatement statement = conn.prepareStatement(sql);
statement.setString(1, quota);
statement.setString(2, provider);
statement.setString(3, bulkname);
statement.setString(4, LocalDateTime.now().toString());
System.out.println(sql);
if (inputStream != null) {
// fetches input stream of the upload file for the blob column
statement.setBlob(5, inputStream);
}
// sends the statement to the database server
int row = statement.executeUpdate();
if (row > 0) {
message = "File uploaded and saved into database";
}
} catch (SQLException ex) {
message = "ERROR: " + ex.getMessage();
ex.printStackTrace();
} finally {
if (conn != null) {
// closes the database connection
try {
conn.close();
} catch (SQLException ex) {
ex.printStackTrace();
}
}
// sets the message in request scope
request.setAttribute("Message", message);
// forwards to the message page
getServletContext().getRequestDispatcher("/Campaign.jsp").forward(request, response);
}
}
/**
* Handles the HTTP <code>POST</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}