Spring Cloud + Vue前后端分离-第9章 大文件断点续与极速秒传

2023-12-28 11:12:48

Spring Cloud + Vue前后端分离-第9章 大文件断点续与极速秒传

作为一个视频网站,一个文件小则几十M,大则上G,上传一个大文件受网络影响很大,文件越大,上传失败率越高

我们要完善文件上传功能,支持断点续传,当文件上传到一半,网络断了,下次再上传时,只上传剩下的部分,这就是断点续传。

极速秒传,听起来很高深,原理其实很简单,就是开始上传前,先检查一下文件是否上传过了,如果已上传过,直接弹出提示,极速秒传成功。

9-1 分片传输的试探

一个文件有10M,每个分片定义为1M,那这个文件就会被分为10片进行传输。

分片上传

1.大文件断点续传与极速秒传:增加big-file组件,分片传输测试成功

把file.vue复制一份重命名big-file.vue

big-file.vue

section.vue

big-file.vue

分片合并

1.大文件断点续传与极速秒传:分片合并测试成功

UploadController.java

9-2 分片上传功能开发1

文件分片管理的模型设计

1.大文件断点续传与极速秒传:文件表增加分片相关字段

all.sql

generatorConfig.xml

分片数据传输

1.大文件断点续传与极速秒传:分片相关的数据传输

经验分享:对于一些不涉及安全性的数据,可以交由前端来计算,这样可以减轻服务端的压力

FileDto.java

big-file.vue

UploadController.java

文件标识的设计

1.大文件断点续传与极速秒传:使用文件生成md5签名,作为文件标识

数据库设计:上传第一个分片时,插入一条记录,上传之后的分片,都是更新记录,只需更新shard_index字段,当然也包括updated_at

数据库设计:shard_index和shard_total的值相等时,表示所有的分片都已上传完成。

数据库设计:不管上传第几个分片,传输的key值是一样的,key跟文件相关,跟分片无关。

big-file.vue

MD5信息摘要算法,常用于密码加密传输与存储,会生成128位二制数,每4个二进制可以转为1个16进制数字,结果是32个16进制数字

UploadController.java

md5.js

var KEY = "!@#QWERT";
/*
 * Configurable variables. You may need to tweak these to be compatible with
 * the server-side, but the defaults work in most cases.
 */
var hexcase = 0;  /* hex output format. 0 - lowercase; 1 - uppercase        */
var b64pad  = ""; /* base-64 pad character. "=" for strict RFC compliance   */
var chrsz   = 8;  /* bits per input character. 8 - ASCII; 16 - Unicode      */

/*
 * These are the functions you'll usually want to call
 * They take string arguments and return either hex or base-64 encoded strings
 */
function hex_md5(s){ return binl2hex(core_md5(str2binl(s), s.length * chrsz));}
function b64_md5(s){ return binl2b64(core_md5(str2binl(s), s.length * chrsz));}
function str_md5(s){ return binl2str(core_md5(str2binl(s), s.length * chrsz));}
function hex_hmac_md5(key, data) { return binl2hex(core_hmac_md5(key, data)); }
function b64_hmac_md5(key, data) { return binl2b64(core_hmac_md5(key, data)); }
function str_hmac_md5(key, data) { return binl2str(core_hmac_md5(key, data)); }

/*
 * Perform a simple self-test to see if the VM is working
 */
function md5_vm_test()
{
  return hex_md5("abc") == "900150983cd24fb0d6963f7d28e17f72";
}

/*
 * Calculate the MD5 of an array of little-endian words, and a bit length
 */
function core_md5(x, len)
{
  /* append padding */
  x[len >> 5] |= 0x80 << ((len) % 32);
  x[(((len + 64) >>> 9) << 4) + 14] = len;

  var a =  1732584193;
  var b = -271733879;
  var c = -1732584194;
  var d =  271733878;

  for(var i = 0; i < x.length; i += 16)
  {
    var olda = a;
    var oldb = b;
    var oldc = c;
    var oldd = d;

    a = md5_ff(a, b, c, d, x[i+ 0], 7 , -680876936);
    d = md5_ff(d, a, b, c, x[i+ 1], 12, -389564586);
    c = md5_ff(c, d, a, b, x[i+ 2], 17,  606105819);
    b = md5_ff(b, c, d, a, x[i+ 3], 22, -1044525330);
    a = md5_ff(a, b, c, d, x[i+ 4], 7 , -176418897);
    d = md5_ff(d, a, b, c, x[i+ 5], 12,  1200080426);
    c = md5_ff(c, d, a, b, x[i+ 6], 17, -1473231341);
    b = md5_ff(b, c, d, a, x[i+ 7], 22, -45705983);
    a = md5_ff(a, b, c, d, x[i+ 8], 7 ,  1770035416);
    d = md5_ff(d, a, b, c, x[i+ 9], 12, -1958414417);
    c = md5_ff(c, d, a, b, x[i+10], 17, -42063);
    b = md5_ff(b, c, d, a, x[i+11], 22, -1990404162);
    a = md5_ff(a, b, c, d, x[i+12], 7 ,  1804603682);
    d = md5_ff(d, a, b, c, x[i+13], 12, -40341101);
    c = md5_ff(c, d, a, b, x[i+14], 17, -1502002290);
    b = md5_ff(b, c, d, a, x[i+15], 22,  1236535329);

    a = md5_gg(a, b, c, d, x[i+ 1], 5 , -165796510);
    d = md5_gg(d, a, b, c, x[i+ 6], 9 , -1069501632);
    c = md5_gg(c, d, a, b, x[i+11], 14,  643717713);
    b = md5_gg(b, c, d, a, x[i+ 0], 20, -373897302);
    a = md5_gg(a, b, c, d, x[i+ 5], 5 , -701558691);
    d = md5_gg(d, a, b, c, x[i+10], 9 ,  38016083);
    c = md5_gg(c, d, a, b, x[i+15], 14, -660478335);
    b = md5_gg(b, c, d, a, x[i+ 4], 20, -405537848);
    a = md5_gg(a, b, c, d, x[i+ 9], 5 ,  568446438);
    d = md5_gg(d, a, b, c, x[i+14], 9 , -1019803690);
    c = md5_gg(c, d, a, b, x[i+ 3], 14, -187363961);
    b = md5_gg(b, c, d, a, x[i+ 8], 20,  1163531501);
    a = md5_gg(a, b, c, d, x[i+13], 5 , -1444681467);
    d = md5_gg(d, a, b, c, x[i+ 2], 9 , -51403784);
    c = md5_gg(c, d, a, b, x[i+ 7], 14,  1735328473);
    b = md5_gg(b, c, d, a, x[i+12], 20, -1926607734);

    a = md5_hh(a, b, c, d, x[i+ 5], 4 , -378558);
    d = md5_hh(d, a, b, c, x[i+ 8], 11, -2022574463);
    c = md5_hh(c, d, a, b, x[i+11], 16,  1839030562);
    b = md5_hh(b, c, d, a, x[i+14], 23, -35309556);
    a = md5_hh(a, b, c, d, x[i+ 1], 4 , -1530992060);
    d = md5_hh(d, a, b, c, x[i+ 4], 11,  1272893353);
    c = md5_hh(c, d, a, b, x[i+ 7], 16, -155497632);
    b = md5_hh(b, c, d, a, x[i+10], 23, -1094730640);
    a = md5_hh(a, b, c, d, x[i+13], 4 ,  681279174);
    d = md5_hh(d, a, b, c, x[i+ 0], 11, -358537222);
    c = md5_hh(c, d, a, b, x[i+ 3], 16, -722521979);
    b = md5_hh(b, c, d, a, x[i+ 6], 23,  76029189);
    a = md5_hh(a, b, c, d, x[i+ 9], 4 , -640364487);
    d = md5_hh(d, a, b, c, x[i+12], 11, -421815835);
    c = md5_hh(c, d, a, b, x[i+15], 16,  530742520);
    b = md5_hh(b, c, d, a, x[i+ 2], 23, -995338651);

    a = md5_ii(a, b, c, d, x[i+ 0], 6 , -198630844);
    d = md5_ii(d, a, b, c, x[i+ 7], 10,  1126891415);
    c = md5_ii(c, d, a, b, x[i+14], 15, -1416354905);
    b = md5_ii(b, c, d, a, x[i+ 5], 21, -57434055);
    a = md5_ii(a, b, c, d, x[i+12], 6 ,  1700485571);
    d = md5_ii(d, a, b, c, x[i+ 3], 10, -1894986606);
    c = md5_ii(c, d, a, b, x[i+10], 15, -1051523);
    b = md5_ii(b, c, d, a, x[i+ 1], 21, -2054922799);
    a = md5_ii(a, b, c, d, x[i+ 8], 6 ,  1873313359);
    d = md5_ii(d, a, b, c, x[i+15], 10, -30611744);
    c = md5_ii(c, d, a, b, x[i+ 6], 15, -1560198380);
    b = md5_ii(b, c, d, a, x[i+13], 21,  1309151649);
    a = md5_ii(a, b, c, d, x[i+ 4], 6 , -145523070);
    d = md5_ii(d, a, b, c, x[i+11], 10, -1120210379);
    c = md5_ii(c, d, a, b, x[i+ 2], 15,  718787259);
    b = md5_ii(b, c, d, a, x[i+ 9], 21, -343485551);

    a = safe_add(a, olda);
    b = safe_add(b, oldb);
    c = safe_add(c, oldc);
    d = safe_add(d, oldd);
  }
  return Array(a, b, c, d);

}

/*
 * These functions implement the four basic operations the algorithm uses.
 */
function md5_cmn(q, a, b, x, s, t)
{
  return safe_add(bit_rol(safe_add(safe_add(a, q), safe_add(x, t)), s),b);
}
function md5_ff(a, b, c, d, x, s, t)
{
  return md5_cmn((b & c) | ((~b) & d), a, b, x, s, t);
}
function md5_gg(a, b, c, d, x, s, t)
{
  return md5_cmn((b & d) | (c & (~d)), a, b, x, s, t);
}
function md5_hh(a, b, c, d, x, s, t)
{
  return md5_cmn(b ^ c ^ d, a, b, x, s, t);
}
function md5_ii(a, b, c, d, x, s, t)
{
  return md5_cmn(c ^ (b | (~d)), a, b, x, s, t);
}

/*
 * Calculate the HMAC-MD5, of a key and some data
 */
function core_hmac_md5(key, data)
{
  var bkey = str2binl(key);
  if(bkey.length > 16) bkey = core_md5(bkey, key.length * chrsz);

  var ipad = Array(16), opad = Array(16);
  for(var i = 0; i < 16; i++)
  {
    ipad[i] = bkey[i] ^ 0x36363636;
    opad[i] = bkey[i] ^ 0x5C5C5C5C;
  }

  var hash = core_md5(ipad.concat(str2binl(data)), 512 + data.length * chrsz);
  return core_md5(opad.concat(hash), 512 + 128);
}

/*
 * Add integers, wrapping at 2^32. This uses 16-bit operations internally
 * to work around bugs in some JS interpreters.
 */
function safe_add(x, y)
{
  var lsw = (x & 0xFFFF) + (y & 0xFFFF);
  var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
  return (msw << 16) | (lsw & 0xFFFF);
}

/*
 * Bitwise rotate a 32-bit number to the left.
 */
function bit_rol(num, cnt)
{
  return (num << cnt) | (num >>> (32 - cnt));
}

/*
 * Convert a string to an array of little-endian words
 * If chrsz is ASCII, characters >255 have their hi-byte silently ignored.
 */
function str2binl(str)
{
  var bin = Array();
  var mask = (1 << chrsz) - 1;
  for(var i = 0; i < str.length * chrsz; i += chrsz)
    bin[i>>5] |= (str.charCodeAt(i / chrsz) & mask) << (i%32);
  return bin;
}

/*
 * Convert an array of little-endian words to a string
 */
function binl2str(bin)
{
  var str = "";
  var mask = (1 << chrsz) - 1;
  for(var i = 0; i < bin.length * 32; i += chrsz)
    str += String.fromCharCode((bin[i>>5] >>> (i % 32)) & mask);
  return str;
}

/*
 * Convert an array of little-endian words to a hex string.
 */
function binl2hex(binarray)
{
  var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
  var str = "";
  for(var i = 0; i < binarray.length * 4; i++)
  {
    str += hex_tab.charAt((binarray[i>>2] >> ((i%4)*8+4)) & 0xF) +
      hex_tab.charAt((binarray[i>>2] >> ((i%4)*8  )) & 0xF);
  }
  return str;
}

/*
 * Convert an array of little-endian words to a base-64 string
 */
function binl2b64(binarray)
{
  var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  var str = "";
  for(var i = 0; i < binarray.length * 4; i += 3)
  {
    var triplet = (((binarray[i   >> 2] >> 8 * ( i   %4)) & 0xFF) << 16)
      | (((binarray[i+1 >> 2] >> 8 * ((i+1)%4)) & 0xFF) << 8 )
      |  ((binarray[i+2 >> 2] >> 8 * ((i+2)%4)) & 0xFF);
    for(var j = 0; j < 4; j++)
    {
      if(i * 8 + j * 6 > binarray.length * 32) str += b64pad;
      else str += tab.charAt((triplet >> 6*(3-j)) & 0x3F);
    }
  }
  return str;
}

index.html

big-file.vue

tool.js

1.大文件断点续传与极速秒传:根据文件标识来新增或修改文件记录,修改分片索引从1开始

实际使用场景中,一个文件太大,当第一次上传一半,失败了。第二次再上传时,有可能隔了一天或更久。

FileService.java

big-file.vue

此时是干净的,我们进行测试?

完成,没有多余的数据

9-3 分片上传功能开发2

分片数据格式转换,统一系列前后端数据交互传参

1.大文件断点续传与极速秒传:分片数据改成base64 进行传输,后端统一用RequestBody 接收数据

big-file.vue

FileDto.java

Base64ToMultipartFile.java

package com.course.server.util;

import org.springframework.web.multipart.MultipartFile;
import sun.misc.BASE64Decoder;

import java.io.*;

public class Base64ToMultipartFile implements MultipartFile {

    private final byte[] imgContent;
    private final String header;

    public Base64ToMultipartFile(byte[] imgContent, String header) {
        this.imgContent = imgContent;
        this.header = header.split(";")[0];
    }

    @Override
    public String getName() {
        // TODO - implementation depends on your requirements
        return System.currentTimeMillis() + Math.random() + "." + header.split("/")[1];
    }

    @Override
    public String getOriginalFilename() {
        // TODO - implementation depends on your requirements
        return System.currentTimeMillis() + (int) Math.random() * 10000 + "." + header.split("/")[1];
    }

    @Override
    public String getContentType() {
        // TODO - implementation depends on your requirements
        return header.split(":")[1];
    }

    @Override
    public boolean isEmpty() {
        return imgContent == null || imgContent.length == 0;
    }

    @Override
    public long getSize() {
        return imgContent.length;
    }

    @Override
    public byte[] getBytes() throws IOException {
        return imgContent;
    }

    @Override
    public InputStream getInputStream() throws IOException {
        return new ByteArrayInputStream(imgContent);
    }

    @Override
    public void transferTo(File dest) throws IOException, IllegalStateException {
        new FileOutputStream(dest).write(imgContent);
    }

    public static MultipartFile base64ToMultipart(String base64) {
        try {
            String[] baseStrs = base64.split(",");

            BASE64Decoder decoder = new BASE64Decoder();
            byte[] b = new byte[0];
            b = decoder.decodeBuffer(baseStrs[1]);

            for(int i = 0; i < b.length; ++i) {
                if (b[i] < 0) {
                    b[i] += 256;
                }
            }

            return new Base64ToMultipartFile(b, baseStrs[0]);
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }
}

UploadController.java

测试

base64格式:文件说明+“,”+文件内容

将文件转成base64 进行传输,优势是变成了常见的字符串类型,劣势是传输的数据会变大。

idea 的控制台默认大小是1M,可通过在设置中搜索console,修改默认配置

LogAspect.java

我们其它的业务表中,不要用shard字段,否则也会不打印日志

设置分片文件名

1.大文件断点续传与极速秒传:设置分片文件名,以分片索引结尾

小提示:当字符串拼接个数太多时,不要使用+,而是使用StringBuffer

UploadController.java

测试

这个日志可以删去,太长了

big-file.vue

支持连续上传多个分片

1.大文件断点续传与极速秒传:重构文件上传代码,将上传功能提取成一个单独的upload方法,使用递归调用upload方法,实现连续上传多个分片功能

在上传结束时,做个判断,如果shardIndex == shardTotal ,表示所有分片都上传完成了,如果shardIndex <?shardTotal,继续上传下一个分片

重构?

我们把生成的方法剪切到后面

把方法都放到下面来?

递归,不断的重复做某一件事(上传分片),直到某个条件成立 (shardIndex == shardTotal) ,退出重复做的事。初学者慎用,容易陷入无限递归,跳不出来。

测试

9-4 分片合并功能开发

按分片顺序合并成原始文件

1.大文件断点续传与极速秒传:按分片顺序合并成原始文件

UploadController.java

package com.course.file.controller.admin;

import com.course.server.dto.FileDto;
import com.course.server.dto.ResponseDto;
import com.course.server.enums.FileUseEnum;
import com.course.server.service.FileService;
import com.course.server.util.Base64ToMultipartFile;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.annotation.Resource;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

@RequestMapping("/admin")
@RestController
public class UploadController {
    private static final Logger LOG = LoggerFactory.getLogger(UploadController.class);
    public static final String BUSINESS_NAME= "文件上传";
    //@Value,注入属性值
    @Value("${file.domain}")
    private String FILE_DOMAIN;

    @Value("${file.path}")
    private String FILE_PATH;

    @Resource
    private FileService fileService;

    @RequestMapping("/upload")
    public ResponseDto upload(@RequestBody FileDto fileDto) throws Exception {
        LOG.info("上传文件开始");
        String use = fileDto.getUse();
        String key = fileDto.getKey();
        String suffix = fileDto.getSuffix();
        String shardBase64 = fileDto.getShard();
        MultipartFile shard = Base64ToMultipartFile.base64ToMultipart(shardBase64);

        //保存文件到本地
        FileUseEnum useEnum = FileUseEnum.getByCode(use);

        //如果文件夹不存在则创建
        String dir = useEnum.name().toLowerCase();
        File fullDir = new File(FILE_PATH + dir);
        if(!fullDir.exists()){
            fullDir.mkdirs();
        }
        //String path = dir + File.separator + key + "." + suffix + "." +fileDto.getShardIndex();
        //小提示:当字符串拼接个数太多时,不要使用+,而是使用StringBuffer
        String path = new StringBuffer(dir)
                .append(File.separator)
                .append(key)
                .append(".")
                .append(suffix)
                .toString();//course/6sfSqfOwzmik4A4icMYuUe.mp4
        String localPath = new StringBuffer(path)
                .append(".")
                .append(fileDto.getShardIndex())
                .toString();//course/6sfSqfOwzmik4A4icMYuUe.mp4.1
        String fullPath =FILE_PATH + localPath;
        File dest = new File(fullPath);
        shard.transferTo(dest);
        LOG.info(dest.getAbsolutePath());

        LOG.info("保存文件记录开始");
        fileDto.setPath(path);
        fileService.save(fileDto);

        ResponseDto responseDto = new ResponseDto();
        fileDto.setPath(FILE_DOMAIN + path);
        responseDto.setContent(fileDto);

        if (fileDto.getShardIndex() == fileDto.getShardTotal()){
            this.merge(fileDto);
        }
        return responseDto;
    }

    public void merge(FileDto fileDto) throws Exception {
        LOG.info("合并分片开始");
        String path = fileDto.getPath();//全路径 http://127.0.0.1:9000/file/f/course/6sfSqfOwzmik4A4icMYuUe.mp4
        //merge里面的方法,只需要相对路径
        path = path.replace(FILE_DOMAIN,"");//course/6sfSqfOwzmik4A4icMYuUe.mp4
        Integer shardTotal = fileDto.getShardTotal();
        File newFile = new File(FILE_PATH + path);
        FileOutputStream outputStream = new FileOutputStream(newFile, true);//文件追加写入
        FileInputStream fileInputStream = null;//分片文件
        byte[] byt = new byte[10 * 1024 * 1024];
        int len;
        try {
            for (int i = 0; i < shardTotal; i++) {
                //读取第i个分片
                fileInputStream = new FileInputStream(FILE_PATH + path + "." + (i + 1));
                course/6sfSqfOwzmik4A4icMYuUe.mp4.1
                while ((len = fileInputStream.read(byt)) != -1) {
                    outputStream.write(byt, 0, len);
                }
            }
        } catch (IOException e) {
            LOG.error("分片合并异常", e);
        }finally {
            try{
                if(fileInputStream != null){
                    fileInputStream.close();
                }
                outputStream.close();
                LOG.info("io流关闭");
            }catch (Exception e){
                LOG.info("io流关闭",e);
            }
        }
        LOG.info("合并分片结束");
    }
}

merge里面的方法,只需要相对路径

保存到本地的分片名是xxx.mp4.1,但是我们返给前端和保存进数据库的path 都用xxx.mp4

测试

合并完成后删除多余分片

1.大文件断点续传与极速秒传:合并成原始文件后,删除所有分片

UploadController.java

big-file.vue

测试

9-5 分片检查与极速秒传

上传分片之前先进行分片检查

1.大文件断点续传与极速秒传:上传分片之前先进行分片检查,支持断点续传

开始上传之前,先检查一下当前的文件是否上传过了(数据库是否有记录),如果上传过了,已经传到第几个分片了。

FileService.java

UploadController.java

big-file.vue

测试

全初始化再次测试上传一半的结果

big-file.vue

也就是说现在只能上传第一个、第二个分片

只请求了两次,现在把代码恢复

再次测试

确实是从中间开始继续上传

极速秒传

1.大文件断点续传与极速秒传:支持极速秒传

big-file.vue

UploadController.java

测试

上传成功,但没有点击保存

再次上传,即为文件极速秒传成功,换一个也是可以

增加上传进度条

1.大文件断点续传与极速秒传:增加上传进度条组件

文件被分成四个分片,所以每个分片上传完,进度条就加25%

可以做成vue 组件,也可以做成js工具类,做成vue 组件的话,就只能在vue框架中使用,做成js 工具类的话,可以在jsp页面,thymeleaf模板页面、angular等前端框架中直接使用。

progress.js

Progress = {
  show: function (width) {
    let _this = this;
    _this.width = width;
    if ($("#progress-div").length > 0) {
      $(".progress").attr("data-percent", width);
      $(".progress-bar").width(width + "%");
    } else {
      let progressDiv = "<div id=\"progress-div\" style=\"z-index: 10011;\n" +
        "    position: fixed;\n" +
        "    padding: 10px;\n" +
        "    margin: 0px 0px 0px -150px;\n" +
        "    width: 300px;\n" +
        "    top: 40%;\n" +
        "    left: 50%;\n" +
        "    text-align: center;\n" +
        "    height: 45px;\n" +
        "    color: rgb(0, 0, 0);\n" +
        "    border: 3px solid rgb(170, 170, 170);\n" +
        "    background-color: rgb(255, 255, 255);\n" +
        "    cursor: wait;\"><div class=\"progress pos-rel\" data-percent=\"" + width + "%\"><div class=\"progress-bar\"></div></div></div>";
      $("#progress-div").remove();
      $("body").append(progressDiv);

      // 背景遮罩
      $("body").append($("<div id=\"progress-overlay\" style=\"z-index: 10010;\n" +
        "  border: none;\n" +
        "  margin: 0px;\n" +
        "  padding: 0px;\n" +
        "  width: 100%;\n" +
        "  height: 100%;\n" +
        "  top: 0px;\n" +
        "  left: 0px;\n" +
        "  background-color: rgb(0, 0, 0);\n" +
        "  opacity: 0.6;\n" +
        "  cursor: wait;\n" +
        "  position: fixed;\"></div>"));
      $(".progress-bar").width(width + "%");
    }

  },

  hide: function () {
    setTimeout(function () {
      $("#progress-div").remove();
      //progress-div:显示的进度条;
      //progress-overlay:背景遮罩,将页面所有的元素挡住,不可点击任何地方,常用于防止重复提交
      $("#progress-overlay").remove();
    }, 1000);
    //上传到100%时,应该关闭进度条,但是一关闭,100%这个值就会一闪而过,所以为了用户体验,故意延迟1秒
  }
};

progress-div:显示的进度条;
progress-overlay:背景遮罩,将页面所有的元素挡住,不可点击任何地方,常用于防止重复提交

上传到100%时,应该关闭进度条,但是一关闭,100%这个值就会一闪而过,所以为了用户体验,故意延迟1秒

big-file.vue

做成js全局工具类,可以直接使用,不需要import

index.html

loading.js

如果不改,loading按钮会被模态框挡住,看不到转圈圈图片?

UploadController.java

测试

再次上传 文件极速秒传成功

讲师头像和课程封面改为用大文件组件

1.大文件断点续传与极速秒传:讲师头像和课程封面改为用大文件组件

course.vue

teacher.vue

修复了一个Bug

big-file.vue

测试

9-6 文件上传流程图

? ? ? ? ? ? ? ? 开始

? ? ? ? ? ? ? ? ? 结束

文章来源:https://blog.csdn.net/qq_52963857/article/details/135182181
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