Java实现大文件分片上传，并暂存到Mysql数据库

本案例用springboot实现了大文件分片上传、上传完成后自动将文件合成为大文件的相关功能
前后端代码以及sql都在下面贴出来了

前端代码

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>分片上传</title>
    <script src="https://cdn.bootcdn.net/ajax/libs/spark-md5/3.0.2/spark-md5.min.js"></script>
</head>
<body>
分片上传
 
<form enctype="multipart/form-data">
    <input type="file" name="fileInput" id="fileInput">
    <input type="button" value="计算文件MD5" onclick="calculateFileMD5()">
    <input type="button" value="上传" onclick="uploadFile()">
    <input type="button" value="检测文件完整性" onclick="checkFile()">
</form>
 
<p>
    文件MD5:
    <span id="fileMd5"></span>
</p>
<p>
    上传结果:
    <span id="uploadResult"></span>
</p>
<p>
    检测文件完整性:
    <span id="checkFileRes"></span>
</p>
 
 
<script>
    //每片的大小
    var chunkSize = 1 * 1024 * 1024;// 1兆
    var uploadResult = document.getElementById("uploadResult")
    var fileMd5Span = document.getElementById("fileMd5")
    var checkFileRes = document.getElementById("checkFileRes")
    var  fileMd5;
 
 
    function  calculateFileMD5(){
        var fileInput = document.getElementById('fileInput');
        var file = fileInput.files[0];
        getFileMd5(file).then((md5) => {
            console.info(md5)
            fileMd5=md5;
            fileMd5Span.innerHTML=md5;
        })
    }
 
    function uploadFile() {
        var fileInput = document.getElementById('fileInput');
        var file = fileInput.files[0];
        console.log(file);
        if (!file) return;
        // if (!fileMd5) return;
 
 
        //获取到文件
        let fileArr = this.sliceFile(file);
        //保存文件名称
        let fileName = file.name;
 
        fileArr.forEach((e, i) => {
            //创建formdata对象
            let data = new FormData();
            data.append("fileName", fileName)
            data.append("chunks", fileArr.length)
            data.append("chunkSize", chunkSize)
            data.append("chunk", i)
            data.append("md5", fileMd5)
            data.append("file", new File([e],fileName));
            upload(data);
        })
 
 
    }
 
    /**
     * 计算文件md5值
     */
    function getFileMd5(file) {
        return new Promise((resolve, reject) => {
            let fileReader = new FileReader()
            fileReader.onload = function (event) {
                let fileMd5 = SparkMD5.ArrayBuffer.hash(event.target.result)
                resolve(fileMd5)
            }
            fileReader.readAsArrayBuffer(file)
        })
    }
 
 
   function upload(data) {
       var xhr = new XMLHttpRequest();
       // 当上传完成时调用
       xhr.onload = function () {
           if (xhr.status === 200) {
               uploadResult.append( '上传成功分片：' +data.get("chunkNumber")+'\t' ) ;
           }
       }
       xhr.onerror = function () {
           uploadResult.innerHTML = '上传失败';
       }
       // 发送请求
       xhr.open('POST', 'http://127.0.0.1:9088/sliceUpload', true);
       xhr.send(data);
    }
 
    function checkFile() {
        var xhr = new XMLHttpRequest();
        // 当上传完成时调用
        xhr.onload = function () {
            if (xhr.status === 200) {
                checkFileRes.innerHTML = '检测文件完整性成功:' + xhr.responseText;
            }
        }
        xhr.onerror = function () {
            checkFileRes.innerHTML = '检测文件完整性失败';
        }
        // 发送请求
        xhr.open('POST', 'http://127.0.0.1:9088/checkFile', true);
        let data = new FormData();
        data.append("md5", fileMd5)
        xhr.send(data);
    }
 
    function sliceFile(file) {
        const chunks = [];
        let start = 0;
        let end;
        while (start < file.size) {
            end = Math.min(start + chunkSize, file.size);
            chunks.push(file.slice(start, end));
            start = end;
        }
        return chunks;
    }
 
</script>
 
</body>
</html>

相关数据库表

CREATE TABLE `gz_upload_file` (
  `id` bigint(20) NOT NULL,
  `state` int(1) DEFAULT '0' COMMENT '上传状态：0-上传未完成；1-已上传；2-已上传ftp;',
  `file_name` varchar(50) DEFAULT NULL COMMENT '文件名称',
  `file_path` varchar(255) DEFAULT NULL COMMENT '上传本地路径',
  `chunks` int(10) DEFAULT NULL COMMENT '分片总数',
  `chunk_size` bigint(20) DEFAULT NULL COMMENT '分片大小',
  `md5` varchar(50) DEFAULT NULL COMMENT 'MD ',
  `created_date` datetime DEFAULT NULL,
  `deleted` varchar(1) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='文件上传任务表';
//
CREATE TABLE `gz_file_slice` (
  `id` bigint(20) DEFAULT NULL,
  `md5` varchar(50) DEFAULT NULL COMMENT '文件md5值',
  `state` int(1) DEFAULT NULL COMMENT '分片上传结果：0-未完成；1-已完成；',
  `chunk` int(10) DEFAULT NULL COMMENT '分片序号',
  `size` bigint(20) DEFAULT NULL COMMENT '当前分片的大小',
  `bytes` longblob COMMENT '分片文件字节数组',
  `created_date` datetime DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='文件分片存储表';

java代码
这里实现了两种将分片合成为目标文件的方式

• 本地存储
• 将文件上传到ftp服务器

Maven依赖包

        <!-- https://mvnrepository.com/artifact/commons-net/commons-net -->
        <dependency>
            <groupId>commons-net</groupId>
            <artifactId>commons-net</artifactId>
            <version>3.9.0</version>
        </dependency>

package com.za.edu.service;

import cn.hutool.core.util.CharsetUtil;
import com.alibaba.fastjson.JSON;
import com.google.common.collect.Lists;
import com.sun.jndi.toolkit.url.UrlUtil;
import com.za.edu.base.BaseBean;
import com.za.edu.bean.FileSlice;
import com.za.edu.bean.UploadFile;
import com.za.edu.dto.FileUploadDTO;
import com.za.edu.enums.UploadStatus;
import com.za.edu.exception.BusinessException;
import com.za.edu.mapper.FileSliceMapper;
import com.za.edu.mapper.UploadFileMapper;
import com.za.edu.sandbox.TenantContext;
import com.za.edu.utils.ExceptionUtil;
import com.za.edu.utils.FileUtil;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile;
import org.springframework.beans.BeanUtils;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.charset.StandardCharsets;
import java.util.Comparator;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import java.util.stream.Collectors;

@Slf4j
@Service
public class FileUploadService {

    // 全局变量来记录已上传的分片序号
    private static final ConcurrentHashMap<String, Integer> uploadChunksMap = new ConcurrentHashMap<>();

    @Resource
    private UploadFileMapper uploadFileMapper;
    @Resource
    private FileSliceMapper fileSliceMapper;
    @Resource
    FTPPoolService ftpPoolService;

    @Transactional
    public void sliceUpload(FileUploadDTO uploadDTO) throws IOException {
        ExceptionUtil.isNull(uploadDTO.getFile(), "文件不能为空");
        if(uploadDTO.getChunk() == 0){
        	//保存文件上传任务
            UploadFile uploadFile = uploadFileMapper.queryByMd5(uploadDTO.getMd5());
            if(uploadFile == null){
                uploadFile = new UploadFile();
                BeanUtils.copyProperties(uploadDTO, uploadFile);
                uploadFile.setId(UploadFile.idGenerator.nextId());
                uploadFile.setFileName(uploadDTO.getFileName());
                uploadFile.setFilePath(uploadDTO.getFilePath());
                uploadFileMapper.add(uploadFile);
            }
        }
		//保存分片
        FileSlice fileSlice = new FileSlice();
        fileSlice.setId(UploadFile.idGenerator.nextId());
        fileSlice.setMd5(uploadDTO.getMd5());
        fileSlice.setState(BaseBean.TRUE);
        fileSlice.setSize(uploadDTO.getSize());
        fileSlice.setChunk(uploadDTO.getChunk());
        fileSlice.setBytes(uploadDTO.getFile().getBytes());
        fileSliceMapper.add(fileSlice);
		//线程变量中保存已上传的分片序号
        uploadChunksMap.put(uploadDTO.getMd5()+"_"+fileSlice.getChunk(), fileSlice.getChunk());
		//当完成了90%的分片上传后，开启是否完成上传任务的判断
        if(fileSlice.getChunk() > (uploadDTO.getChunks()*0.9)){
            synchronized (uploadDTO.getMd5()){
                List<String> chunks = Lists.newArrayList(uploadChunksMap.keySet());
                System.out.println("当前已完成了"+chunks.size()+"分片上传");
                System.out.println("当前已完成了"+chunks.size()+"分片上传");
                if(chunks.size() == uploadDTO.getChunks()){
                    System.out.println("共计"+chunks.size()+"分片，已上传完成");
                    new Thread(() -> {
                        List<FileSlice> fileSlices = fileSliceMapper.queryByMd5(uploadDTO.getMd5());
                        /**   将文件写入本地  **/
                        File mergeFile = new File("G:\\Downloads\\"+uploadDTO.getFileName());
                        try(RandomAccessFile randomAccessFileWriter = new RandomAccessFile(mergeFile, "rw")){
                        for (FileSlice chunkFile : fileSlices) {
                            //单个字节的写入
    //                        for(byte b : chunkFile.getBytes()){
    //                            randomAccessFileWriter.write(b);
    //                        }
                            //批量字节的写入
                            randomAccessFileWriter.write(chunkFile.getBytes(), 0, chunkFile.getBytes().length);
                        }
                        }catch (Exception err){
                            log.error("", err);
                        }
                        /**   将文件写入ftp  **/
//                            FTPClient ftpClient = ftpPoolService.borrowObject();
//                            String fName = uploadDTO.getFileName();
//                            try {
//                                final String ffName = new String(fName.getBytes("GBK"), StandardCharsets.UTF_8);
//                                // 设置PassiveMode传输
//                                ftpClient.enterLocalPassiveMode();
//                                // 设置以二进制流的方式传输
//                                ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
//                                ftpClient.setControlEncoding(CharsetUtil.GBK);
//                                // 检查远程是否存在文件
//                                String uploadPath = "ftp";
//                                //切换到工作目录
//                                if (!ftpClient.changeWorkingDirectory(uploadPath)) {
//                                    ftpClient.makeDirectory(uploadPath);
//                                    ftpClient.changeWorkingDirectory(uploadPath);
//                                }
//                                for (FileSlice chunkFile : fileSlices) {
//                                    System.out.println("==============-----------------------------==================");
//                                    if(chunkFile.getChunk() == 0){
//                                        ftpClient.storeFile(ffName, new ByteArrayInputStream(chunkFile.getBytes(), 0, chunkFile.getBytes().length));
//                                        Thread.sleep(200);
//                                    }else{
//                                        ftpClient.appendFile(ffName, new ByteArrayInputStream(chunkFile.getBytes(), 0, chunkFile.getBytes().length));
//                                        Thread.sleep(200);
//                                    }
//                                    System.out.println("已完成了向FTP服务器上传第"+chunkFile.getChunk()+"分片数据");
//                                }
//
//                            }catch (Exception err){
//                                log.error("", err);
//                                throw new BusinessException(err.getMessage());
//                            }
                        //清空
                        fileSliceMapper.deleteByMd5(uploadDTO.getMd5());
                    }).start();
                }
            }
        }
    }
}