png

Question

是否可以将存储在数据库表中的blob类型图像转换为png？我需要使用REST将图像作为png发送到网站，但是如果我发送数据库blob项目（在发送之前转换为base64），数据将被发送，但是当我点击它时图像将不会加载节目。谁能给我一个如何做到这一点的小费？

提前致谢， 的Tamas

Edit1：这是我正在使用的整个代码

第一个请求将文件上传到网站，并发回一个令牌，然后我可以将该文件附加到第二个请求。 正如您所看到的，两个请求机构都声明内容类型是image / png，因此我并不完全理解可能出现的问题。

    create or replace procedure publish_error_tickets(p_priority_id varchar2, p_description varchar2)
    is
      req1 utl_http.req;
      res1 utl_http.resp;
      req2 utl_http.req;
      res2 utl_http.resp;
      lc_entire_message clob;
      l_attachment clob;
      url1 varchar2(4000) := 'http://revprox.local/inno-dev.cloudapp.net/redmine/uploads.json';
      url2 varchar2(4000) := 'http://revprox.local/inno-dev.cloudapp.net/redmine/projects/support-interface-teszt/issues.json';

      name varchar2(4000);
      token varchar2(4000);
      buffer varchar2(4000); 
      content varchar2(4000);
      p_id number;
      p_image blob;
      l_request_body clob;
      l_request_body_length number;

      l_offset number := 1;
      l_amount number := 2000;
      l_buffer varchar2(4000);
    begin

      select max(id) into p_id from t_tkt_temp_images;
      select image into p_image from t_tkt_temp_images where id = p_id;


       l_request_body := apex_web_service.blob2clobbase64(p_image);

  l_request_body_length := length(l_request_body);

  req1 := utl_http.begin_request(url1, 'POST',' HTTP/1.1');
  utl_http.set_header(req1, 'User-Agent', 'mozilla/4.0'); 
  utl_http.set_header(req1, 'Content-Type', 'application/octet-stream'); 
  utl_http.set_header(req1, 'Content-Length', l_request_body_length);
  utl_http.set_header(req1, 'Content-Disposition', 'attachment; filename="file.png"');
      utl_http.set_header(req1, 'X-Redmine-API-Key', '0asddq3t23w4esdf');

      while l_offset < l_request_body_length loop
        dbms_lob.read(l_request_body, l_amount, l_offset, l_buffer);
        utl_http.write_text(req1, l_buffer);
        l_offset := l_offset + l_amount;
      end loop;

      res1 := utl_http.get_response(req1);

      begin
        loop
          utl_http.read_text(res1, buffer);
          lc_entire_message := buffer;
        end loop;

        utl_http.end_response(res1);
      exception
        when utl_http.end_of_body 
        then
          utl_http.end_response(res1);
      end;

      apex_json.parse(lc_entire_message);
      token := apex_json.get_varchar2(p_path => 'upload.token');

      content := 
      '{
      "issue": {
        "subject": "Hibajegy",
        "priority_id": '|| 1 ||',
        "description": "asd",
        "uploads": [
          {"token": "'||token||'", "filename": "file.png", "content_type": "image/png"}
        ]
        }
      }';

      req2 := utl_http.begin_request(url2, 'POST',' HTTP/1.1');
      utl_http.set_header(req2, 'user-agent', 'mozilla/4.0'); 
      utl_http.set_header(req2, 'content-type', 'application/json'); 
      utl_http.set_header(req2, 'Content-Length', length(content));
      utl_http.set_header(req2, 'X-Redmine-API-Key', '0asddq3t23w4esdf');

      utl_http.write_text(req2, content);
      res2 := utl_http.get_response(req2);

      begin
        loop
          utl_http.read_line(res2, buffer);
        end loop;

        utl_http.end_response(res2);
      exception
        when utl_http.end_of_body 
        then
          utl_http.end_response(res2);
      end;
    end publish_error_tickets;