Send text message to web from http

Here I have a web app which I can text message in the message box and click on "post" (like web facebook you can write comments). Is there any way that I can post the message by writing some code in java with the help of HTTP? The information I find out that might be helping: 1. In devtool there are some get method through which I can extract content but there is no set method to post or change the content. 2. By inspecting post button I found a corresponding js: onclick="return P.text_editor.save('new_followup')"