Spring MVC Tutorials 44 - Web Services 14 (HTTP Response Headers and ResponseEntity for a REST API) Video Lecture | MVC Tutorials: Web Programming Course - Web Development

you
guys my name is ambush chorus and I
welcome you to gone to series in the
previous tutorial we learnt about a
response entity concept so what we
learned overall if you use a response
entity as a return type with any REST
API controller method then you are
simply allowing that controller method
to be able to specify a response body
and status within it so after including
response entity as return type and this
statement in the previous tutorial now
when I'm going to make put it rest on
this REST API with this information I
would get this response from the server
with this response body and this status
exactly what I have specified over here
as first argument and second argument to
this response entity constructor and
whatever I've just described in a very
brief manner I explained in detail in
the previous tutorial let's proceed
further and try to understand in this
tutorial the concept of HTTP response
headers and how to send your own
customized headers to decline from
within this rest API controller method
selects that because if you look at the
overall response Mercer has sent me for
this request I would find that it has
sent me body status as well as some
bunch of key value pairs under this Edel
step now what are these key value pins
in general developers call these key
value pairs as HTTP response headers so
question is what are these key value
pairs and the wire server has sent the
you know these key value pairs to me for
this request in the response and answer
is these key value pairs simply describe
the overall response message in a more
appropriate manner let me explain you
the importance of for these key value
pairs by explaining these one by one
after looking at the value of
content-type key a client would be able
to understand in what format the
response body has come to it it's in
JSON format XML format or in some other
format well by looking at it cried is
sure of one thing that a response body
is actually in its XML format C so in
whatever format response body has been
sent to the client that's going to be
described by this key value pair this
second key value pair simply describes
at what date and timing this response
was produced by the server this third
one
simply talks about what kind of web
server has produced this response and
this last one simply talks about what
kind of encoding technique has been used
to transfer this response from server to
the client so these key value pairs
simply provide some extra information to
the client you know about the overall
response and nothing more than that now
the point is these are not the only HTTP
headers what a server might send to the
client along with a response there are
so many HTTP response headers available
some of the important ones are listed on
the screen along with their meaning so
for this request by default this server
has sent me these four key value pairs
now in different circumstances and
situations your server may decide to
include an appropriator
HTTP header or headers along with the
response message now as an application
developer what if you want to add you
know your own customized HTTP header
along with the response from within this
REST API controller method you don't
want to depend on the server to you know
choose an appropriator HTTP header and
include the same width in the response
method you want to have a control over
it you want to specify a response HTTP
header
from within this question I control the
method so how to achieve that well
that's kind of very easy to achieve as
all you need to do is to create an
object of HTTP headers class and then go
on specifying all key value pairs what
you want to send along with the response
message over here say you want to add
this key and this value so you want to
add one more key value pair in the
response now only thing that's remaining
is to pass this object reference as the
second argument to the response entity
constructive that's all about a face so
after this change now what is going to
happen these customized HTTP headers
would also be sent by the server in the
response to the client when any user is
going to make a request for this REST
API controller method let me show you
cool so here in addition to these
default key value pairs server has now
send these customized HTTP headers what
we specified over here so overall
concept is guys when you pass only one
argument to response entity constructor
it considers that hot women as HTTP
status to be sent to the client in the
response and when you pass two arguments
it considers first argument as response
body and sitting as response status and
when you pass three arguments to it it
considers first as a response body
second as HTTP headers and third bonus
response HTTP status softer this you
know
now we are able to send our own
customized response headers to the
client along with the response in the
next tutorial I will talk about how to
be able to develop a REST API which
demands post kind of requests to be made
on it
alright guys a big thank you for
learning REST API concepts using spring
MVC framework with me if you have any
feedback or any constructive comment or
you want me to upload a video on a very
specific topic in this series or you
want me to upload a brand new series on
this channel gone to series do post me a
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on this email id for all of your queries
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catch you in the next part of this
tutorial