django 上有一个后端，还有一个 postgres 数据库，用于存储有关项目的数据，包括图片。从数据库获取图片存在问题，我已经看过足够多的解决方案，但没有一个有效。
序列化器.py
import base64
import uuid
import imghdr
class Base64ImageField(serializers.ImageField):
def to_internal_value(self, data):
if isinstance(data, str) and 'data:' in data and ';base64,' in data:
header, data = data.split(';base64,')
try:
decoded_file = base64.b64decode(data)
except (TypeError, ValueError):
self.fail('invalid_image')
file_name = str(uuid.uuid4())[:12]
file_extension = self.get_file_extension(file_name, decoded_file)
complete_file_name = f"{file_name}.{file_extension}"
data = ContentFile(decoded_file, name=complete_file_name)
return super(Base64ImageField, self).to_internal_value(data)
def get_file_extension(self, file_name, decoded_file):
extension = imghdr.what(file_name, decoded_file)
return extension or 'jpg'
class CreateItemSerializer(serializers.ModelSerializer):
owner = serializers.ReadOnlyField(source='owner.username')
photo = Base64ImageField(required=True)
class Meta:
model = CreateItem
fields = '__all__'
def create(self, validated_data):
items = CreateItem.object.create_item(
name = validated_data.get('name'),
price = validated_data.get('price'),
description = validated_data.get('description'),
type_item = validated_data.get('type_item'),
photo=validated_data.get('photo')
)
return items
views.py
class GetItemView(APIView):
serializer_class = CreateItemSerializer
def get(self, request):
items = CreateItem.object.all()
response_data = {
'items': [
{
'photo': item.photo,
'name': item.name,
'description': item.description,
'type_item': item.type_item,
'price': item.price,
}
for item in items
]
}
return Response(response_data, status=status.HTTP_200_OK)
完整的错误追溯
Internal Server Error: /api/v1/item/items-get/
Traceback (most recent call last):
File "/home/anton/Documents/e-m/e-market/backend/my_backend/venv_em/lib/python3.12/site-packages/django/core/handlers/exception.py", line 55, in inner
response = get_response(request)
^^^^^^^^^^^^^^^^^^^^^
File "/home/anton/Documents/e-m/e-market/backend/my_backend/venv_em/lib/python3.12/site-packages/django/core/handlers/base.py", line 220, in _get_response
response = response.render()
^^^^^^^^^^^^^^^^^
File "/home/anton/Documents/e-m/e-market/backend/my_backend/venv_em/lib/python3.12/site-packages/django/template/response.py", line 114, in render
self.content = self.rendered_content
^^^^^^^^^^^^^^^^^^^^^
File "/home/anton/Documents/e-m/e-market/backend/my_backend/venv_em/lib/python3.12/site-packages/rest_framework/response.py", line 74, in rendered_content
ret = renderer.render(self.data, accepted_media_type, context)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/anton/Documents/e-m/e-market/backend/my_backend/venv_em/lib/python3.12/site-packages/rest_framework/renderers.py", line 100, in render
ret = json.dumps(
^^^^^^^^^^^
File "/home/anton/Documents/e-m/e-market/backend/my_backend/venv_em/lib/python3.12/site-packages/rest_framework/utils/json.py", line 25, in dumps
return json.dumps(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.12/json/__init__.py", line 238, in dumps
**kw).encode(obj)
^^^^^^^^^^^
File "/usr/lib/python3.12/json/encoder.py", line 200, in encode
chunks = self.iterencode(o, _one_shot=True)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.12/json/encoder.py", line 258, in iterencode
return _iterencode(o, 0)
^^^^^^^^^^^^^^^^^
File "/home/anton/Documents/e-m/e-market/backend/my_backend/venv_em/lib/python3.12/site-packages/rest_framework/utils/encoders.py", line 52, in default
return obj.decode()
^^^^^^^^^^^^
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xff in position 0: invalid start byte
[04/Oct/2024 18:59:30] "GET /api/v1/item/items-get/ HTTP/1.1" 500 115134
也许问题出在desirealizer上，但如果是这样，我不知道如何解决它。
您遇到的错误是由于序列化器和视图中处理图像数据的方式造成的。问题是，当您尝试序列化响应的图像字段时，它会尝试将二进制图像数据解码为 UTF-8 文本，这是不正确的。让我们修改您的代码以正确处理这个问题
序列化器.py
from rest_framework import serializers
from django.core.files.base import ContentFile
import base64
import uuid
import imghdr
class Base64ImageField(serializers.ImageField):
def to_internal_value(self, data):
if isinstance(data, str) and 'data:' in data and ';base64,' in data:
header, data = data.split(';base64,')
try:
decoded_file = base64.b64decode(data)
except (TypeError, ValueError):
self.fail('invalid_image')
file_name = str(uuid.uuid4())[:12]
file_extension = self.get_file_extension(file_name, decoded_file)
complete_file_name = f"{file_name}.{file_extension}"
data = ContentFile(decoded_file, name=complete_file_name)
return super(Base64ImageField, self).to_internal_value(data)
def get_file_extension(self, file_name, decoded_file):
extension = imghdr.what(file_name, decoded_file)
return extension or 'jpg'
def to_representation(self, value):
if not value:
return None
return value.url # Return the URL of the image instead of the file object
class CreateItemSerializer(serializers.ModelSerializer):
owner = serializers.ReadOnlyField(source='owner.username')
photo = Base64ImageField(required=True)
class Meta:
model = CreateItem
fields = '__all__'
def create(self, validated_data):
return CreateItem.objects.create(**validated_data)
views.py
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework import status
from .models import CreateItem
from .serializers import CreateItemSerializer
class GetItemView(APIView):
def get(self, request):
items = CreateItem.objects.all()
serializer = CreateItemSerializer(items, many=True)
return Response({'items': serializer.data}, status=status.HTTP_200_OK)