testInjection.java

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import java.io.IOException;
import java.io.InputStream;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.SocketException;

public class MainActivity extends AppCompatActivity {

    public EditText injectionUrl = null;
    public EditText injectionHost = null;
    public EditText injectionLineCount = null;
    public Button connectButton = null;
    public TextView outputView = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        injectionUrl = (EditText) findViewById(R.id.injection_url);
        injectionHost = (EditText) findViewById(R.id.injection_host);
        injectionLineCount = (EditText) findViewById(R.id.newlines);

        outputView = (TextView)findViewById(R.id.output);
        connectButton = (Button)findViewById(R.id.connect_button);

        connectButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                outputView.setText("Connecting...");
                Runnable runnable = new Runnable() {
                    @Override
                    public void run() {
                        InetSocketAddress direct = new InetSocketAddress("104.156.247.105", 8080);
                        Socket remoteSocket = new Socket();
                        try {
                            remoteSocket.setSoTimeout(30 * 1000);
                            remoteSocket.connect(direct, 5 * 1000);

                            StringBuilder request = new StringBuilder("");
                            request.append(String.format("%s %s HTTP/1.1\r\n", "CONNECT", injectionUrl.getText()));
                            request.append(String.format("Host: %s", injectionHost.getText()));
                            for (int i = 0; i < Integer.parseInt(injectionLineCount.getText().toString()); i++) {
                                request.append("\r\n");
                            }

                            remoteSocket.getOutputStream().write(request.toString().getBytes());
                            InputStream inStream = remoteSocket.getInputStream();
                            final StringBuilder response = new StringBuilder("");
                            while (true){
                                byte b = (byte) inStream.read();
                                response.append((char)b);
                                if (response.toString().contains("\r\n\r\n")){
                                    break;
                                }
                            }

                            runOnUiThread(new Runnable() {
                                @Override
                                public void run() {
                                    outputView.setText(response);
                                }
                            });
                        } catch (SocketException e) {
                            runOnUiThread(new Runnable() {
                                @Override
                                public void run() {
                                    outputView.setText("Connection failed");
                                }
                            });

                            e.printStackTrace();
                        } catch (IOException e) {
                            runOnUiThread(new Runnable() {
                                @Override
                                public void run() {
                                    outputView.setText("Connection Failed");
                                }
                            });
                            e.printStackTrace();
                        }
                    }
                };

                new Thread(runnable).start();
            }

        });
    }
}