Question

我需要帮助。我正在开发用于上传文本文件的应用程序。这一刻我遇到了一些我无法理解的错误。这是我的代码：

的index.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
        pageEncoding="ISO-8859-1"%>
<!DOCTYPE HTML>

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Servlet based API for querying text file</title>
<link rel="stylesheet" href="css/bootstrap.min.css" type="text/css">
</head>
<body>
    <h3>Please choose file</h3>
    <div class="container">
    <form action="TextProccessing" method="post"
        enctype="multipart/form-data">

        <div class="form-group">
            <label for="browseTxt">Upload file:</label> 
            <input type="file" name="browseTxt" id="browseTxt" value="select text file">
            <p class="help-block">
                <b>Note:</b> Please choose .txt file only
            </p>
        </div>

        <BUTTON class="btn btn-default" type="submit">Upload</BUTTON>

    </form>
    </div>

    <h2>Place for text</h2>
    <div class="container"></div>
</body>
</html>

TextProccessing

package com.controller;

import java.io.File;
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 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;

@MultipartConfig(maxFileSize = 16177215)
public class TextProccessing extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private final static String RESULT_PAGE = "/result.jsp";
    private final String dbURL = "jdbc:mysql://127.0.0.1:3306/textfilesdb";
    private final String dbUser = "root";
    private final String dbPassword = "root";
    // for this moment
    private String ﬁle_Name_test = "ﬁle_Name_test";
    private String file_size_test = "file_size_test";
    private String ﬁleCreationDate_test = "ﬁleCreationDate_test";

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        InputStream inputStream = null;

        Part filePart = request.getPart("browseTxt");
        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(dbURL, dbUser, dbPassword);

            // constructs SQL statement
            String sql = "INSERT INTO files(ﬁle_Name, file_size, ﬁleCreationDate, text_file) values (?, ?, ?, ?)";
            PreparedStatement statement = conn.prepareStatement(sql);
            statement.setString(1, ﬁle_Name_test);
            statement.setString(2, file_size_test);
            statement.setString(3, ﬁleCreationDate_test);

            if (inputStream != null) {
                // fetches input stream of the upload file for the blob column
                statement.setBlob(4, 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);
            getServletContext().getRequestDispatcher(RESULT_PAGE).forward(request, response);
        }

    }
}

似乎没问题，但我有这样的错误堆栈跟踪

browseTxt 1189 text / plain com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException：你有一个 SQL语法错误;查看与您的手册相对应的手册 MySQL服务器版本，在'？le_Name附近使用正确的语法， file_size，？leCreationDate，text_file）值（'？le_Name_test'，第1行的'file_' sun.reflect.NativeConstructorAccessorImpl.newInstance0（本机方法） at sun.reflect.NativeConstructorAccessorImpl.newInstance（未知来源）at sun.reflect.DelegatingConstructorAccessorImpl.newInstance（未知来自java.lang.reflect.Constructor.newInstance（未知来源）在com.mysql.jdbc.Util.handleNewInstance（Util.java:400）at com.mysql.jdbc.Util.getInstance（Util.java:383）at com.mysql.jdbc.SQLError.createSQLException（SQLError.java:980）at at com.mysql.jdbc.MysqlIO.checkErrorPacket（MysqlIO.java:3847）at at com.mysql.jdbc.MysqlIO.checkErrorPacket（MysqlIO.java:3783）at at com.mysql.jdbc.MysqlIO.sendCommand（MysqlIO.java:2447）at at com.mysql.jdbc.MysqlIO.sqlQueryDirect（MysqlIO.java:2594）at at com.mysql.jdbc.ConnectionImpl.execSQL（ConnectionImpl.java:2545）at com.mysql.jdbc.PreparedStatement.executeInternal（PreparedStatement.java:1901）在 com.mysql.jdbc.PreparedStatement.executeUpdate（PreparedStatement.java:2113）在 com.mysql.jdbc.PreparedStatement.executeUpdate（PreparedStatement.java:2049）在 com.mysql.jdbc.PreparedStatement.executeUpdate（PreparedStatement.java:2034）在com.controller.TextProccessing.doPost（TextProccessing.java:68）at javax.servlet.http.HttpServlet.service（HttpServlet.java:648）at at javax.servlet.http.HttpServlet.service（HttpServlet.java:729）at at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:291）在 org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:206）在 org.apache.tomcat.websocket.server.WsFilter.doFilter（WsFilter.java:52）在 org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:239）在 org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:206）在 org.apache.catalina.core.StandardWrapperValve.invoke（StandardWrapperValve.java:219）在 org.apache.catalina.core.StandardContextValve.invoke（StandardContextValve.java:106）在 org.apache.catalina.authenticator.AuthenticatorBase.invoke（AuthenticatorBase.java:502）在 org.apache.catalina.core.StandardHostValve.invoke（StandardHostValve.java:142）在 org.apache.catalina.valves.ErrorReportValve.invoke（ErrorReportValve.java:79）在 org.apache.catalina.valves.AbstractAccessLogValve.invoke（AbstractAccessLogValve.java:616）在 org.apache.catalina.core.StandardEngineValve.invoke（StandardEngineValve.java:88）在 org.apache.catalina.connector.CoyoteAdapter.service（CoyoteAdapter.java:518）在 org.apache.coyote.http11.AbstractHttp11Processor.process（AbstractHttp11Processor.java:1091）在 org.apache.coyote.AbstractProtocol $ AbstractConnectionHandler.process（AbstractProtocol.java:673）在 org.apache.tomcat.util.net.NioEndpoint $ SocketProcessor.doRun（NioEndpoint.java:1526）在 org.apache.tomcat.util.net.NioEndpoint $ SocketProcessor.run（NioEndpoint.java:1482） at java.util.concurrent.ThreadPoolExecutor.runWorker（Unknown Source） at java.util.concurrent.ThreadPoolExecutor $ Worker.run（Unknown Source）在 org.apache.tomcat.util.threads.TaskThread $ WrappingRunnable.run（TaskThread.java:61）在java.lang.Thread.run（未知来源）

我的数据库结构

创建数据库TextFilesDB;

使用TextFilesDB;

CREATE TABLE files（id int（11）NOT NULL AUTO_INCREMENT，
ﬁle_Name varchar（45）NOT NULL，file_size varchar（45）DEFAULT NULL，ﬁleCreationDate varchar（45）DEFAULT NULL，text_file mediumblob，PRIMARY KEY（id））ENGINE = InnoDB DEFAULT CHARSET = utf16

Answer 1

您的列名称似乎有一些格式问题。你能尝试替换

吗？

INSERT INTO files(ﬁle_Name, file_size, ﬁleCreationDate, text_file) values (?, ?, ?, ?)

通过

INSERT INTO files(file_Name, file_size, fileCreationDate, text_file) values (?, ?, ?, ?)

1 个答案: