Hi, thanks for the detailed answer.
The reason why I used the brackets was that in some cases (browsers) only the first value was returned. (Even if there were more then one hidden field with that name) Also mentioned here: http://stackoverflow.com/a/6547234 - PHP is also resolving the variable without brackets. There are various other questions at stackoverflow mentioning to get the variable without brackets: http://stackoverflow.com/questions/6547209/passing-array-using-html-form-hidden-element http://stackoverflow.com/questions/4237090/how-to-pass-array-through-hidden-field http://stackoverflow.com/questions/29076219/javascript-storing-array-of-objects-in-hidden-field Don't know if this should be supported. kind regards Tobias 2017-05-03 12:05 GMT+02:00 André Warnier (tomcat) <a...@ice-sa.com>: > On 03.05.2017 11:23, Tobias Soloschenko wrote: > >> Hello everyone, >> >> I just updated to tomcat 8.0.43 and I noticed a special behavior I want to >> discuss. (I don't know if this only occurs with this version) >> >> When I add two hidden fields within a form like: >> >> <input type="hidden" name="array[]" value="1" /> >> >> <input type="hidden" name="array[]" value="2" /> >> >> >> I just thought to access the parameter values within the java api like >> >> String[] myArray = httpServletRequest.getParameterValues("array"); >> >> >> In my case however I just can access them like (with brackets): >> >> String[] myArray = httpServletRequest.getParameterValues("array[]"); >> >> >> This also applies to httpServletRequest.getParameterMap().containsKey >> >> >> Is this an expected behavior? >> >> >> > I would tend to say : yes, it is expected. > (This also has nothing to do with tomcat per se, and is more of the domain > of the HTML and HTTP specifications). > > I have not checked the relevant HTML/HTTP specs to verify which characters > precisely are allowed in the "name" attribute of a HTML <form> field. > But assuming that "[" and "]" /are/ allowed in such attributes, then that > is the name under which the value of this parameter will be sent by the > browser to the server. > > More precisely : if you have in your form an <input> element such as : > > <input type="hidden" name="xyz[123abc]" value="1" /> > > (whatever "xyz[123abc]" may be, in terms of valid characters) > then "xyz[123abc]" is the name/label of this parameter, and the browser > will send the corresponding input field value to the server as something > like : > > xyz[123abc]=1 > > The fact that this label /resembles/ the way in which you would invoke an > array in Java (or any other server-side programming language) is pure > coincidence. > > In other words again, in your above example, if you replaced "array[]" by > "array][" (or "array)(", or "array(xyz)" or "variable#1") everywhere, it > would work just the same. It's just a label. > > And the fact that in your example they are seen as an array on the java > side, is just because there is more than one value sent by the browser with > that same label, and the POST parsing logic on the server side then makes > this into an array of values. > > This all being said, I would not name any input fields in a form with a > name like "array[]". That is bound to create confusion, as you yourself can > now attest. > You can name is "ferrari" instead; but that does not mean that on the > server side, you should expect something red with 4 wheels and 12 cylinders. > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > >
