How to modify HTTP request headers from an Android app?

Question

Is there a way for me to capture all HTTP requests that are being sent from my app, and modify their headers before they are sent? I want to modify their referer header so that the server that the requests are sent to thinks as if they are coming from a web browser instead of a mobile application. Thank you!

Update: To give you more context, I am planning to port a chrome extension Instant Music into an Android app by using Phonegap. Some YouTube videos that are allowed on PC are not allowed on mobile and I suspect that's because youtube player embedded inside an android app doesn't have a referrer header. I am trying to find a solution to this problem so that I can play such videos on mobile too.

Answer 1

Youtube detects user browser's Agent String which contains information about the browser. If you were to use a WebView to show the youtube video instead, then it would be possible to set that WebView's Agent String. You can find agent strings of different browsers on the internet. I found some here: Agent Strings.

Here's how i play Bob Marley's song that is not allowed on mobile phones by impersonating a Firefox browser:

package com.my.myapplication;

import android.app.Activity;
import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;

    public class MyActivity extends Activity {

        private WebView mWebView ;

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            mWebView  = new WebView(this);
            // Enable javascript
            mWebView.getSettings().setJavaScriptEnabled(true);
            // Impersonate Mozzila browser
            mWebView.getSettings().setUserAgentString("Mozilla/5.0 (Windows NT 6.2; Win64; x64; rv:21.0.0) Gecko/20121011 Firefox/21.0.0");
            final Activity activity = this;

            mWebView.setWebViewClient(new WebViewClient() {
                public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
                    Toast.makeText(activity, description, Toast.LENGTH_SHORT).show();
                }
            });

            mWebView .loadUrl("http://youtube.com/watch?v=x59kS2AOrGM");
            setContentView(mWebView);
        }

    }

EDIT:

You also need to give permission for your Activity to use the internet, by adding this line to your AndroidManifest.xml:

<uses-permission android:name="android.permission.INTERNET" />