10. 开发后端文件上传API接口

MAX_FILE_SIZE = 100 * 1024 * 1024  # 100MB
UPLOAD_DIR = BASE_DIR / "uploads"
UPLOAD_DIR.mkdir(parents=True, exist_ok=True)

ALLOWED_EXTENSIONS = {
    ".jpg", ".jpeg", ".png", ".gif", ".webp",
    ".pdf", ".doc", ".docx", ".xls", ".xlsx", ".zip",
}

import os
import time
from pathlib import Path
import uuid
import shutil
from fastapi import APIRouter, File, UploadFile

from app.common.exceptions import BusinessException
from app.common.response import Response
from app.config import ALLOWED_EXTENSIONS, BASE_DIR, MAX_FILE_SIZE, UPLOAD_DIR

router = APIRouter(prefix="/files", tags=["文件管理"])

@router.post("/upload")
def upload(file: UploadFile = File(...)):
    """文件上传的接口"""
    if not file.filename:
        raise BusinessException(message="文件名不能为空")

    # 原始的文件名  用户头像.jpg
    orignal_name = os.path.basename(file.filename)
    # 文件后缀 .jpg
    ext = Path(orignal_name).suffix.lower()
    if ext not in ALLOWED_EXTENSIONS:
        raise BusinessException(message=f"不自持的文件后缀：{ext}")
    # 文件大小校验
    if file.size and file.size > MAX_FILE_SIZE:
        raise BusinessException(
            message=f"文件不能超过 {MAX_FILE_SIZE // 1024 // 1024}MB"
        )
    # 设置唯一的文件名称   199323213213_ddadaqwerq.jpg
    disk_name = f"{int(time.time() * 1000)}_{uuid.uuid4().hex[:8]}{ext}"
    # 文件存储的实际路径
    save_path = UPLOAD_DIR / disk_name

    # 流式写文件
    with open(save_path, "wb") as f:
        shutil.copyfileobj(file.file, f)

    return Response.success(
        data={
            "original_name": orignal_name,
            "disk_name": disk_name,
            "size": file.size,
            "url": f"/uploads/{disk_name}",
        }
    )

from fastapi import APIRouter
from app.api.auth import router as auth_router
from app.api.user import router as user_router
from app.api.files import router as files_router

api = APIRouter(prefix="/api")

api.include_router(auth_router)
api.include_router(user_router)
api.include_router(files_router)

from fastapi.staticfiles import StaticFiles

from app.config import UPLOAD_DIR

# 挂载静态资源：/uploads/xxx.jpg → uploads/xxx.jpg
app.mount("/uploads", StaticFiles(directory=UPLOAD_DIR), name="uploads")