HTTP - Client (User agents)

An HTTP client in HTTP is also known as the user agents because user-agent is the name of a header field that identify the client.

Every web client is a HTTP client.

HTTP identifies the client (ie user-agent_ using the user-agent header (even when the client is not operated by a user).

• every browser is an HTTP client.
• HTTP diagnostic tool are also client
• postman

• java/net/HttpURLConnection
• Java - Jetty (Web Server)
• OkHttp Website (code) 35,3k
• https://github.com/googleapis/google-http-java-client 1k
• https://github.com/AsyncHttpClient/async-http-client 5,3
• https://openjdk.java.net/groups/net/httpclient/intro.html Jdk 11

URL - cURL (Client for URLs)

Call an host on a webserver without modifying the host file

curl --user-agent "Mozilla 5.0" -H "Host: domainName.com" http://182.186.33.19/

• RFC2616 - HTTP/1.1 specification