[Q] App doesn't get site source code - Android Q&A, Help & Troubleshooting

Hey xda-members,
Before I tell my problem I want to say that I tried real hard to follow the rules and find the right place to post my question in. I hope I found the right place to ask, if not I'm really sorry about that. :angel:
I'm new to Android development and read through some basics and tryed some things, now I wanted to expand my knowledge and try to regex some information from a website's source code. That thing was never a problem before when I used just java, but here in Android Studio it makes a difference somewhere, I followed the book I've read and put the "<uses-permission android:name="android.permission.INTERNET" />" in the AndroidManifest.xml and tryed all kind of ways to get the source code of an specified URL, but couldn't do it, sometimes it didn't do anything and just jumped to the error catch and sometimes it just returned an empty string.
My current code looks like this:
Code:
package com.example.onlineregex;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.widget.EditText;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.StatusLine;
import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.BasicResponseHandler;
import org.apache.http.impl.client.DefaultHttpClient;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
public class MainActivity extends Activity {
[user=439709]@override[/user]
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
[user=439709]@override[/user]
public void onClick(View view) {
get_source();
}
});
}
void get_source()
{
TextView src = (TextView) findViewById(R.id.textView1);
try {
URL daurl = new URL(""); // Some URL, removed because of 10 posts thing
URLConnection conn = daurl.openConnection();
BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String inputLine;
String finalout = "";
while ((inputLine = in.readLine()) != null)
finalout += inputLine;
in.close();
src.setText(finalout);
}
catch (Exception e) {
src.setText(e.getMessage());
}
}
}
nothing special I could do wrong I guess.
I hope you could help me out with this, because I can't solve this on my own, even after reading through all kinds of suggestions..
Greetz