What does 5B and 5D in POST requests stand for

Question

I m trying to write a Java class to log in to a certain website  The data sent in the POST request to log in is  user 5Blogin 5D username amp user 5Bpassword 5D 123456  I m curious what the  5B and  5D means in the key user login   How do I encode these data

User · Accepted Answer

As per this answer over here  str  foo 20 5B12 5D  encodes foo  12     20 is space  5B is     and  5D is       This is called percent encoding and is used in encoding special characters in the url parameter values   EDIT By the way as I was reading https   developer mozilla org en-US docs JavaScript Reference Global Objects encodeURI Description  it just occurred to me why so many people make the same search  See the note on the bottom of the page      Also note that if one wishes to follow the more recent RFC3986   for URL s  making square brackets reserved  for IPv6  and thus not   encoded when forming something which could be part of a URL  such as a   host   the following may help    function fixedEncodeURI  str        return encodeURI str  replace   5B g       replace   5D g            Hopefully this will help people sort out their problems when they stumble upon this question

User · Answer

Not least important is why these symbols occur in url  See https   www php net manual en function parse-str php 76792  specifically   parse str  foo   1 amp foo   2 amp foo   3    bar     the above produces    bar     foo    gt    1    2    3        and what is THE method to separate query vars in arrays  in php  at least

User · Answer

Well it s the usual url encoding   So they stand for    respectively

User · Answer

The data would probably have been posted originally from a web form looking a bit like this  but probably much more complicated     lt form action  http   example com  method  post  gt     User login     lt input name  user login        gt  lt br   gt    User password  lt input name  user password     gt  lt br   gt      lt input type  submit    gt   lt  form gt    If the method were  get  instead of  post   clicking the submit button would take you to a URL looking a bit like this      http   example com  user 5Blogin 5D username amp user 5Bpassword 5D 123456   or      http   example com  user login  username amp user password  123456   The web server on the other end will likely take the user login  and user password  parameters  and make them into a user object with login and password fields containing those values

User · Answer

To take a quick look  you can percent-en decode using this online tool

User · Answer

is replaced by  5B 5D at URL encoding time

User · Answer

They represent   and    The encoding is called  URL encoding

[java] What does %5B and %5D in POST requests stand for?

Examples related to java

Examples related to post

Examples related to httpwebrequest