How to invoke http requests from android application

In most of the android applications it is essential that app may need to connect to internet and make some HTTP requests. In this article i’ll be demonstrating about making simple HTTP Requests in android. Below are the code snippets to handle HTTP requests. Creating HTTP Client and HTTP Post

// Creating HTTP client
HttpClient httpClient = new DefaultHttpClient();
 
// Creating HTTP Post
HttpPost httpPost = new HttpPost("http://www.example.com/login");

Bulding Post Parameters The following code will create post parameters pair with key and value.

// Building post parameters, key and value pair
List nameValuePair = new ArrayList(2);
nameValuePair.add(new BasicNameValuePair("email", "user@gmail.com"));
nameValuePair.add(new BasicNameValuePair("password", "encrypted_password"));

URL Encoding POST data Before making HTTP request you need to encode the post data in order to convert all string data into valid url format.

// Url Encoding the POST parameters
try {
    httpPost.setEntity(new UrlEncodedFormEntity(nameValuePair));
}
catch (UnsupportedEncodingException e) {
    // writing error to Log
    e.printStackTrace();
}

Finally making HTTP Request Finally you need to execute httpPost using the httpClient created before.

// Making HTTP Request
try {
    HttpResponse response = httpClient.execute(httpPost);
 
    // writing response to log
    Log.d("Http Response:", response.toString());
 
} catch (ClientProtocolException e) {
    // writing exception to log
    e.printStackTrace();
         
} catch (IOException e) {
    // writing exception to log
    e.printStackTrace();
}

Final Code The following is the final code to make http Requests. I am writing response to log. Check your Log report in Eclipse to see your http response.

package com.onlinecodegeek.android.server.httprequests;
 
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
 
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
 
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
 
public class AndroidHTTPRequestsActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
 
        // Creating HTTP client
        HttpClient httpClient = new DefaultHttpClient();
        // Creating HTTP Post
        HttpPost httpPost = new HttpPost(
                "http://www.example.com/login");
 
        // Building post parameters
        // key and value pair
        List nameValuePair = new ArrayList(2);
        nameValuePair.add(new BasicNameValuePair("email", "user@gmail.com"));
        nameValuePair.add(new BasicNameValuePair("message",
                "Hi, trying Android HTTP post!"));
 
        // Url Encoding the POST parameters
        try {
            httpPost.setEntity(new UrlEncodedFormEntity(nameValuePair));
        } catch (UnsupportedEncodingException e) {
            // writing error to Log
            e.printStackTrace();
        }
 
        // Making HTTP Request
        try {
            HttpResponse response = httpClient.execute(httpPost);
 
            // writing response to log
            Log.d("Http Response:", response.toString());
        } catch (ClientProtocolException e) {
            // writing exception to log
            e.printStackTrace();
        } catch (IOException e) {
            // writing exception to log
            e.printStackTrace();
 
        }
    }
}

SHARE

Onlinecodegeek