用springboot，vue，mybatis和elementUI实现上传PDF文件到数据库，需要上传到数据库的内容有文件名，文件上传时间，文件路径，上传者的编号。请告诉我springboot配置文件，domain代码，controller代码，service代码，前端vue和element代码，mybatis代码和数据库建表语句，并用注释讲解

很高兴为您提供解答。以下是您所需的代码和注释：

1. 配置文件 application.properties

# 数据库连接配置
spring.datasource.url=jdbc:mysql://localhost:3306/db_name?useUnicode=true&characterEncoding=utf-8&useSSL=false
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

# Mybatis 配置
mybatis.mapper-locations=classpath:mapper/*.xml
mybatis.type-aliases-package=com.example.demo.domain

# 文件上传配置
spring.servlet.multipart.enabled=true
spring.servlet.multipart.max-file-size=10MB
spring.servlet.multipart.max-request-size=10MB
spring.servlet.multipart.file-size-threshold=2KB

2. Domain 代码

package com.example.demo.domain;

import java.util.Date;

public class PdfFile {
    private Integer id;
    private String fileName;
    private Date uploadTime;
    private String filePath;
    private Integer uploaderId;

    // getter 和 setter 方法省略
}

3. Controller 代码

package com.example.demo.controller;

import com.example.demo.domain.PdfFile;
import com.example.demo.service.PdfFileService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.IOException;
import java.util.Date;

@RestController
@RequestMapping("/pdf")
public class PdfFileController {
    @Autowired
    private PdfFileService pdfFileService;

    @PostMapping("/upload")
    public String uploadPdfFile(@RequestParam("file") MultipartFile file, @RequestParam("uploaderId") Integer uploaderId) {
        if (file.isEmpty()) {
            return "上传失败，请选择文件";
        }

        String fileName = file.getOriginalFilename();
        String filePath = "D:/pdf_files/" + fileName;
        File dest = new File(filePath);
        try {
            file.transferTo(dest);
            PdfFile pdfFile = new PdfFile();
            pdfFile.setFileName(fileName);
            pdfFile.setUploadTime(new Date());
            pdfFile.setFilePath(filePath);
            pdfFile.setUploaderId(uploaderId);
            pdfFileService.addPdfFile(pdfFile);
            return "上传成功";
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "上传失败！";
    }
}

4. Service 代码

package com.example.demo.service;

import com.example.demo.domain.PdfFile;

public interface PdfFileService {
    void addPdfFile(PdfFile pdfFile);
}

package com.example.demo.service.impl;

import com.example.demo.dao.PdfFileMapper;
import com.example.demo.domain.PdfFile;
import com.example.demo.service.PdfFileService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class PdfFileServiceImpl implements PdfFileService {
    @Autowired
    private PdfFileMapper pdfFileMapper;

    @Override
    public void addPdfFile(PdfFile pdfFile) {
        pdfFileMapper.addPdfFile(pdfFile);
    }
}

5. 前端 Vue 和 Element 代码

<template>
  <div>
    <el-upload
      class="upload-demo"
      action="/pdf/upload"
      :data="{ uploaderId: uploaderId }"
      :on-success="handleSuccess"
      :before-upload="beforeUpload"
      :file-list="fileList"
      multiple>
      <el-button size="small" type="primary">点击上传</el-button>
      <div slot="tip" class="el-upload__tip">只能上传 PDF 文件</div>
    </el-upload>
  </div>
</template>

<script>
export default {
  data() {
    return {
      uploaderId: 1, // 上传者的编号
      fileList: []
    }
  },
  methods: {
    beforeUpload(file) {
      const isPdf = file.type === 'application/pdf';
      if (!isPdf) {
        this.$message.error('只能上传 PDF 文件');
      }
      return isPdf;
    },
    handleSuccess(response, file, fileList) {
      if (response === '上传成功') {
        this.$message.success(response);
      } else {
        this.$message.error(response);
      }
    }
  }
}
</script>

6. Mybatis 代码

package com.example.demo.dao;

import com.example.demo.domain.PdfFile;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface PdfFileMapper {
    @Insert("insert into pdf_file(file_name, upload_time, file_path, uploader_id) values(#{fileName}, #{uploadTime}, #{filePath}, #{uploaderId})")
    void addPdfFile(PdfFile pdfFile);
}

7. 数据库建表语句

CREATE TABLE `pdf_file` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `file_name` varchar(255) NOT NULL,
  `upload_time` datetime NOT NULL,
  `file_path` varchar(255) NOT NULL,
  `uploader_id` int(11) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

希望以上代码和注释能够帮助您实现上传 PDF 文件到数据库的功能。