将 ImageOutputStream 转换为 byte[]

import javax.imageio.stream.ImageOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

public class ImageOutputStreamToByteArrayExample {
    public static byte[] convertToByteArray(ImageOutputStream imageOutputStream) throws IOException {
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int bytesRead;
        
        while ((bytesRead = imageOutputStream.read(buffer)) != -1) {
            byteArrayOutputStream.write(buffer, 0, bytesRead);
        }
        
        return byteArrayOutputStream.toByteArray();
    }
}