Send HTTP POST request with Socket

This is an example of how to send an HTTP POST request with a Socket. A socket is an endpoint for communication between two machines. Sending an HTTP POST request using a Socket implies that you should:

• Get the InetAddress of a specified host, using the host’s name, with getByName(String host) API method of InetAddress.
• Create a new Socket and connect it to a specified port number at a specified IP address.
• Get the output stream of the socket, using getOutputStream() API method of Socket.
• Create an OutputStreamWriter with the socket ouputstream that uses the given UTF-8 encoder.
• Create a BufferedWriter that uses a default-sized output buffer.
• Use write(String str) API method to send the headers and the parameters and flush() API method to flush the stream.
• Get the socket input stream, using getInputStream() API method of Socket.
• Create a new BufferedReader, using a new InputStreamReader with the socket input stream.
• Use readLine() API method to read the response.
• Don’t forget to close both the BufferedWriter and the BufferedReader using the close() API methods.

Let’s take a look at the code snippet that follows:  

package com.javacodegeeks.snippets.core;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.InetAddress;
import java.net.Socket;
import java.net.URLEncoder;

public class SendHTTPPOSTRequestWithSocket {
	
	public static void main(String[] args) {
		
		try {
			
			String params = URLEncoder.encode("param1", "UTF-8")
+ "=" + URLEncoder.encode("value1", "UTF-8");
			params += "&" + URLEncoder.encode("param2", "UTF-8")
+ "=" + URLEncoder.encode("value2", "UTF-8");

			String hostname = "mysite.com";
			int port = 80;
			
			InetAddress addr = InetAddress.getByName(hostname);
			Socket socket = new Socket(addr, port);
			String path = "/myapp";

			// Send headers
			BufferedWriter wr =
     new BufferedWriter(new OutputStreamWriter(socket.getOutputStream(), "UTF8"));
			wr.write("POST "+path+" HTTP/1.0rn");
			wr.write("Content-Length: "+params.length()+"rn");
			wr.write("Content-Type: application/x-www-form-urlencodedrn");
			wr.write("rn");

			// Send parameters
			wr.write(params);
			wr.flush();

			// Get response
			BufferedReader rd = new BufferedReader(new InputStreamReader(socket.getInputStream()));
			String line;
			
			while ((line = rd.readLine()) != null) {
			    System.out.println(line);
			}
			
			wr.close();
			rd.close();
			
		}
		catch (Exception e) {
			e.printStackTrace();
		}
		
	}

}

  
This was an example of how to send an HTTP POST request using a Socket in Java.