ORA-29263 thrown error ONLY when URL becomes LONG - oracle

Question

I am trying to call a restful service from my ora pkg; Sometimes with the same code, this service is reached successfully and a response is returned; but when the message in the url becomes longer ==> ORA-29273 http request and ORA-29263 http protocol are thrown; I do not change anything between calls, only messages to be sent from this URL; Below is my procedure:
PROCEDURE SEND_SMS(username VARCHAR2,
password VARCHAR2,
phone VARCHAR2,
message VARCHAR2,
code VARCHAR2,
P_RESPONSE OUT VARCHAR2) AS
v_request UTL_HTTP.req;
v_response UTL_HTTP.resp;
v_text VARCHAR2(1024);
v_url VARCHAR2(1024);
v_message VARCHAR2(1024);
BEGIN
BEGIN
P_RESPONSE := '';
v_message := REPLACE(message,' ', '%20');
v_url := 'http://myservicelink.com/SendSMS?strUsername=' |
username || '&strPassword=' || password ||
'&strPhone=' || phone || '&strcode=' || code ||
'&strMessage=' || v_message;
v_request := UTL_HTTP.begin_request(v_url);
DBMS_OUTPUT.put_line(v_url);
v_response := UTL_HTTP.get_response(v_request);
LOOP
BEGIN
UTL_HTTP.read_text(v_response, v_text);
DBMS_OUTPUT.put_line(v_text);
EXCEPTION
WHEN UTL_HTTP.end_of_body THEN
NULL;
END;
EXIT WHEN v_text IS NULL;
END LOOP;
UTL_HTTP.end_response(v_response);
IF v_response.status_code <> 200 THEN
P_RESPONSE := v_response.reason_phrase;
END IF;
EXCEPTION
WHEN OTHERS THEN
P_RESPONSE := 'An error has occured: ' || SQLERRM;
END;
END SEND_SMS;
So when v_message becomes longer, exception is thrown. What can be the error; Please note that the same link is called from outside ORA pkg with same inputs --> myservice is reached;
Here is a template of my working message:
Dear X, you have been registered to our app. You can download the app for iPhone at link of app store or for android at link of
Not working:
Dear X, you have been registered to our app. You can download the app for iPhone at link of app store or for android at link of play store
your

Answer 1

The difference between your two strings isn't just length; the second one has a newline character in it as well. You are replacing spaces using:
v_message := REPLACE(message,' ', '%20');
but that won't deal with any other illegal characters.
If you change that to use the utl_url.escape() function:
v_message := utl_url.escape(message);
then it will escape the new line as well, so you end up with this for the first message (same as your current code gives):
Dear%20X,%20you%20have%20been%20registered%20to%20our%20app.%20You%20can%20download%20the%20app%20for%20iPhone%20at%20link%20of%20app%20store%20or%20for%20android%20at%20link%20of
but this for the second:
Dear%20X,%20you%20have%20been%20registered%20to%20our%20app.%20You%20can%20download%20the%20app%20for%20iPhone%20at%20link%20of%20app%20store%20or%20for%20android%20at%20link%20of%20play%20store%0Ayour
The newline has been encoded as %0A. Depending on what else is in the message, you may need to pass true as the second argument instead of letting it default to false; the difference is explained in the documentation link above.