Question

在我的模型中，我想通过覆盖保存方法来格式化图像字段

我已经在模型中完成了

public void downloadcsv() {

    String server = "servername.host";
    int port = 21;
    String user = "username";
    String pass = "password";

    FTPClient ftpClient = new FTPClient();
    try {

        ftpClient.connect(server, port);
        ftpClient.login(user, pass);
        ftpClient.enterLocalPassiveMode();
        ftpClient.setFileType(FTP.BINARY_FILE_TYPE);

        String remoteFile = "/serverpath/daten.csv";
        File downloadFile = new File("localpath/daten.csv");
        OutputStream outputStream = new BufferedOutputStream(new FileOutputStream(downloadFile));

        boolean success = ftpClient.retrieveFile(remoteFile, outputStream);

        outputStream.close();

        if (success) {
            System.out.println("File has been downloaded successfully.");
        }

    } catch (IOException ex) {

        System.out.println("Error: " + ex.getMessage());
        ex.printStackTrace();

    } finally {
        try {
            if (ftpClient.isConnected()) {
                ftpClient.logout();
                ftpClient.disconnect();
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }
}

但是出现此属性错误

from PIL import Image as Img
from io import StringIO
from django.core.files.uploadedfile import InMemoryUploadedFile


class Blog(models.Model):
    Blog_image= models.ImageField(upload_to="...", blank=True)

    def save(self, *args, **kwargs):
    if self.Blog_image:
        image = Img.open(StringIO.StringIO(self.Blog_image.read()))
        image.thumbnail((900,300), Img.ANTIALIAS)
        output = StringIO.StringIO()
        image.save(output, format='JPEG', quality=150)
        output.seek(0)
        self.Blog_image = InMemoryUploadedFile(output,'ImageField', "%s.jpg" %self.Blog_image.name, 'image/jpeg', output.len, None)
    super(Blog, self).save(*args, **kwargs)

任何人都可以向我解释为什么我会收到此错误吗？

我的python版本是3.6.4

我的Django版本是2.0.7

Answer 1

得到解决方案

from PIL import Image
from io import BytesIO
from django.core.files.uploadedfile import InMemoryUploadedFile
import sys

    def save(self, *args, **kwargs):
    imageTemproary = Image.open(self.Blog_image)
    outputIoStream = BytesIO()
    imageTemproaryResized = imageTemproary.resize( (900,300) ) 
    imageTemproaryResized.save(outputIoStream , format='JPEG', quality=150)
    outputIoStream.seek(0)
    self.Blog_image = InMemoryUploadedFile(outputIoStream,'ImageField', "%s.jpg" %self.Blog_image.name.split('.')[0], 'image/jpeg', sys.getsizeof(outputIoStream), None)
    super(Blog, self).save(*args, **kwargs)

使用BytesIO进行操作，效果很好

Answer 2

输出= StringIO.StringIO（）

将其更改为：

输出= StringIO（）

您已经导入了io.StringIO（）。

AttributeError：类型对象'_io.StringIO'没有属性'StringIO'

2 个答案: