HttpConnection using java

Many of you might be wondering how to make a HttpConnection from java. Here is a small program that helps you to make the connection from pure java code. This has been tested and I have been using this from a long time. It’s very simple and easy to use. If required you can just copy and start using this code, I don’t think you will need to change any part of this code. It’s ready to use as is. Just place this code in your utli folder of the code and just call this method. That’s it.

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;

/**
 * This class is used to make the HTTP Connection from a java code.
 * @author Prabesh Bhaskaran
 */
public class MakeHttpConnection {

    /**
     * The getConnection method takes 2 parameters, the URL string of the site that you would like to connect 
     * and the other parameter is the parameter that you would like to pass through the query.
     * @param urlString: The URL of the site that you would like to connect
     * @param query: The parameter that you would like to pass to the site.
     * @throws java.lang.Exception 
     * @return 
     */
 public String getConnection(String urlString, String query) throws Exception {
            String retStr = "";
            URL url = new URL(urlString);
            String responseString = "";

            HttpURLConnection urlConnection = (HttpURLConnection)url.openConnection();
            urlConnection.setDoOutput(true);
            urlConnection.setRequestMethod("POST");
            urlConnection.setAllowUserInteraction(false);
            urlConnection.setRequestProperty("Content-type","application/x-www-form-urlencoded"); // the content-length should not be necessary, but we're cautious

            BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(urlConnection.getOutputStream()));
            bw.write(query);
            bw.write("\r\n");
            bw.flush();
            bw.close();

            if (urlConnection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                BufferedReader br = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
                String inputLine;

                while ((inputLine = br.readLine()) != null) {
                    responseString = responseString+inputLine;
                } 
                System.out.println("responseString="+responseString);
 }
 return responseString;
    }
}

As the saying goes

Necessity is the mother of all invention

this program was also developed when there was a necessity. My office had blocked many sites from viewing due to some junk reasons, but I needed some sites that would help me. So from a java code I just make a httpconnection and call the required site, this code will return a string that will give the full website page. That’s it I was able to view the website even when my office had blocked that particular site.

Go ahead and try out. Let me know if you need any help or if you come across any issues when using this code.

Happy coding!!!.