-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Saurav,
On 1/7/19 13:13, Saurav Sarkar wrote: > Thanks a lot Chris for the reply. > > I think even if i parse the request myself i have to always load > the content in memory/disk. > > Because in order to extract the file uploaded from the request , i > have to go through the whole request stream and trim down the > boundaries. Exactly. Neither you *nor Tomcat* really have many options, here. - -chris > On Thu, Jan 3, 2019 at 3:20 AM Christopher Schultz < > ch...@christopherschultz.net> wrote: > > Saurav, > > On 1/2/19 12:20, Saurav Sarkar wrote: >>>> Hi All, >>>> >>>> This is regarding the reading of multi part content in java >>>> server side. >>>> >>>> ServletRequest has an API getParts() API for reading the >>>> parts of a multi part request >>>> https://docs.oracle.com/javaee/6/api/javax/servlet/http/HttpServlet Req > >>>> >>>> uest.html#getParts() > <https://docs.oracle.com/javaee/6/api/javax/servlet/http/HttpServletRe quest.html#getParts()> >>>> >>>> > > > . >>>> >>>> It has part.getInputStream which can be used to read the >>>> content of a specific part. >>>> >>>> Tomcat also provides an implementation for this API. >>>> >>>> But this API parses the multi part content and keeps it in >>>> memory. If the size increase then the content can be >>>> offloaded to disk. >>>> >>>> Why does the getPart API or any multi part parsing need to >>>> load the content in memory ? Why can't direct streaming of >>>> content happen ? Loading the content in memory and >>>> reading/writing to disk brings extra cost. This will be >>>> specially costly when large files are getting uploaded. > > True. You can always limit the part-size or request-size, but you > can't stream huge uploads if you want to use getParts(). > >>>> Is there no way where at least the file content loading >>>> could be avoided ? > > Yes, there is a way. > > Instead of calling HttpServletRequest.getParameter* or > HttpServletRequest.getPart*, you can call > HttpServletRequest.getInputStream and parse everything yourself. > >>>> It may be not be a very specific question for tomcat but more >>>> applicable to any servlet container. > > Correct, this is applicable to any servlet container. > > The multipart code in Tomcat parses everything to memory/disk at > once because servlet code needs to be able to call > HttpServletRequest.getParameter(String) in any order regardless of > what how the request data is actually ordered. Also, getParts must > return before the calling code can actually do anything with the > data. There is no "register a stream handler for a multipart > request part called 'foo'" or anything like that. > > If you want those semantics, you'll have to parse the request > yourself. > > -chris >> >> --------------------------------------------------------------------- >> >> >> To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org >> For additional commands, e-mail: users-h...@tomcat.apache.org >> >> > -----BEGIN PGP SIGNATURE----- Comment: Using GnuPG with Thunderbird - https://www.enigmail.net/ iQIzBAEBCAAdFiEEMmKgYcQvxMe7tcJcHPApP6U8pFgFAlwzzNUACgkQHPApP6U8 pFgNJg//VoweS5Ve1jgMYi4e2yekWL4lexpAkm1Apu+mwOku93c7oQ28RW1x/h54 ShuQbh+smt5DWPoM3Qu9F/PvKEiNcLyRxLyhmf5c/SRSRoLrBrZt66Oq+SKmekrb wugGyLOP6ZrhULXJOlNqIa/oh5pBA/GU7cEGTjcLdCzz3i58c+0H/XyO7EG5QjvS rX6umdKNp86bMgSjw9wL/KNCB7KbLguhPxIo93S6AjRNtbXWxThuZGlLb6x6fjpK J+nsnuwhv8nxrpCawdq+hKABMFL9PsIq28Yf5MZ7gLzgCr/iYibDXDJpF9puBe5r xKOhAvhTy7yK84C44QzkRCBzqTp2+d/0xL1rQCyMU7wq4fDZm8ZKd8QsPOzNd0QG Sfb+/HMu00UlZTcOhNmIdPMrGwuDT2cwRlgWZGBJAnA7gJNzoJ1ZY/F+62UJPin7 UrFH5IMP0Gw3cJ5PEHH/pi3nTTb+FCtMobb3AogPvfXE+jDVb3vC1Shg52UdvX2h I63h8+l/UHhcy+ldP+9ov2EeoBgUfn+7feUKTbuyefmPjsKZdj8xeRC4CoWG6UT3 xDEMSdZ/EhkGRmPhzBcPPlPHR9vBjyY26V7Sk0AapqLSVRxBbG4s4HeGRJxdNHj8 r1vyaawX66/6ACzL3pp7XqHdshTRoxR8nZuBuBSq3a7LQDjO1Ps= =IapN -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
