npm run start # 启动前端
npm run server # 启动后端主要是利用js form表单方式进行上传
let formData = new FormData();
formData.append('file', _file);
formData.append('filename', _file.name);
instance
.post('/upload_single', formData)
.then((res) => {
const { code } = res;
if (code === 0) {
alert('file 上传成功');
return;
}
console.log(res);
return Promise.reject(data.codeText);
})
.catch((e) => {
console.log(e);
});// 利用FildReader 得到文件的base64
/**
* FileReader.readAsDataURL()开始读取指定的Blob中的内容。一旦完成，result属性中将包含一个data: URL格式的Base64字符串以表示所读取文件的内容。
* **/
const getFileBase64 = (file) => {
return new Promise((resolve) => {
let fileReader = new FileReader();
fileReader.readAsDataURL(file);
fileReader.onload = (e) => {
resolve(e.target.result);
};
});
};
base64 = await getFileBase64(file);
upload_input.value = ''; // 用于初始化input
try {
const data = await instance.post(
'/upload_single_base64',
{
file: encodeURIComponent(base64), // 防止乱码问题 decodeURIComponent 对应
filename: file.name,
},
{
headers: {
'Content-Type': 'application/x-www-form-urlencoded',
},
}
);
const { code } = data;
if (code === 0) {
alert('文件上传成功!');
}
throw data.codeText; // 抛出异常
} catch (e) {
// 文件上传错误
} finally {
//
}/**
*
* @param {} file
* @returns
* 根据内容生成hash名字
*/
// SparkMD5 生成HASH
const getBufferByFile = (file) => {
return new Promise((resolve) => {
let fileReader = new FileReader();
fileReader.readAsArrayBuffer(file);
fileReader.onload = (e) => {
let buffer = e.target.result;
console.log(buffer);
const spark = new SparkMD5.ArrayBuffer();
spark.append(buffer);
const HASH = spark.end();
const suffix = /\.([0-9a-zA-Z]+)$/.exec(file.name)[1];
console.log(HASH);
resolve({
buffer,
HASH,
suffix,
filename: `${HASH}.${suffix}`,
});
};
});
};
// 缩略图，可以用base64 来展示
const base64 = await getFileBase64(file);
const { filename } = await getFileBase64(_file);
let formData = new FormData();
formData.append('file', _file);
formData.append('filename', filename); // 处理名字,服务端不提供名字编译
instance
.post('/upload_single_name', formData)
.then((res) => {
const { code } = res;
if (code === 0) {
alert('file 上传成功');
return;
}
console.log(res);
return Promise.reject(data.codeText);
})
.catch((e) => {
console.log(e);
});
});上传进度，主要是靠axios中回调
try {
let formData = new FormData();
formData.append('file', file);
formData.append('filename', file.filename);
const data = await instance.post('/upload_single', formData, {
// onPuloadProgress； 变化来更新进度
onUploadProgress: (e) => {
console.log(e);
const { loaded, total } = e;
console.log(
`${(loaded / total) * 100}%`,
' `${loaded/total*100}%`'
);
upload_progress.style.display = 'block';
upload_progrees_value.style.width = `${
(loaded / total) * 100
}%`;
},
});
const { code } = data;
if (code === 0) {
upload_progrees_value.style.width = `100%`;
alert('文件上传成功!');
return;
}
throw data.codeText;
} catch (e) {
//
console.log(e);
alert('文件上传失败');
} finally {
this.value = '';
}主要是对上传列表做一个遍历上传。 结合Promise.all() 表示是否全部上传成功！
const _files = files.map((item) => {
const fm = new FormData();
const curLi = upload_list_arr.find(
(liBox) => liBox.getAttribute('key') === item.key
);
const curSpan = curLi
? curLi.querySelector('span:nth-last-child(1)')
: null;
fm.append('file', item.file);
fm.append('filename', item.filename);
return instance
.post('/upload_single', fm, {
onUploadProgress(e) {
// 监听每一个上传进度
const { loaded, total } = e;
const progress = `${((loaded / total) * 100).toFixed(
2
)}%`;
if (curSpan) {
curSpan.innerText = progress;
}
},
})
.then((data) => {
const { code } = data;
if (code === 0) {
if (curSpan) {
curSpan.innerText = '100%';
}
return Promise.resolve(data);
}
return Promise.reject(data.codeText);
});
});
Promise.all(_files).then((res) => {
console.log(res);
alert('上传成功');
});拖拽上传没有什么特殊的， 值得注意的是， drop 中的事件参数回携带 dataTransfer， 里面包含着 files。，提取出来，走上传即可！
// 拖拽进入
dragBox.addEventListener('dragenter', function (e) {
// console.log('拖拽进入')
e.preventDefault();
this.style.border = '1px solid red';
});
// 拖拽放下
dragBox.addEventListener('drop', function (e) {
e.preventDefault();
this.style.border = '';
const {
dataTransfer: { files },
} = e;
const file = files[0];
uploadFile(file);
});
dragBox.addEventListener('dragover', function (e) {
e.preventDefault();
});切片上传相对于上面，复杂一些, 当然也没有想象中的难！
- 上传文件
- 利用Bole.prototype.slice() 方法对文件进行切片， 对每一个文件进行HASH 唯一标识
- 从服务器获取已经上传的切片，判断是否有些切片已经上传
- 上传切片
- 上传完切片，通知服务端合并切片
upload_button_upload.addEventListener('click', async function () {
// 点击开始上传
let chunkList = [];
let alreadyChunkList = [];
console.log(_file);
let maxSize = 1024 * 1024;
let maxCount = Math.ceil(_file.size / maxSize); // 最大允许分割的切片数量为30
let index = 0;
if (!_file) return alert('请先选择图片');
const { HASH, suffix } = await changeBuffer(_file);
// 判断当前文件可以切出多少切片
if (maxCount > 10) {
// 如果切片数量大于最大值
maxSize = _file.size / 10; // 则改变切片大小
maxCount = 10;
}
console.log(maxCount, 'maxCount');
console.log(maxSize, 'maxSize');
while (index < maxCount) {
chunkList.push({
file: _file.slice(index * maxSize, (index + 1) * maxSize),
filename: `${HASH}_${index + 1}.${suffix}`,
});
index++;
}
// 先获取已经上传的切片
const data = await instance.post(
'/upload_already',
{
HASH: HASH,
},
{
headers: {
'Content-Type': 'application/x-www-form-urlencoded',
},
}
);
index = 0
const complate = async () => {
index++;
let progress = `(${index}/${maxCount})%` // 进度条
if (index >= maxCount) {
console.log('ok, 切片完成')
}
}
const { fileList } = data;
alreadyChunkList = fileList
console.log(chunkList, 'chunkList');
chunkList = chunkList.map((item) => {
if (alreadyChunkList.length > 0 && alreadyChunkList.includes(item.filename)) {
debugger
// 表示切片已经存在
complate()
return;
}
const fm = new FormData();
fm.append('file', item.file);
fm.append('filename', item.filename);
return new Promise((sovle) => {
instance
.post('/upload_chunk', fm)
.then(() => {
complate()
sovle();
})
.catch(() => {
//
});
});
});
Promise.all(chunkList).then(() => {
instance
.post(
'/upload_merge',
{
HASH: HASH,
count: maxCount,
},
{
headers: {
'Content-Type': 'application/x-www-form-urlencoded',
},
}
)
.then((res) => {
console.log('ok');
});
});
});