import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.ViewGroup;
import android.widget.TextView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_display_message);
    
    // Get the Intent that started this activity and extract the string
    Intent intent = getIntent();
    String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);

    // Capture the layout's TextView and set the string as its text
    TextView textView = (TextView) findViewById(R.id.textView);
    textView.setText(message);
}



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import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.ViewGroup;
import android.widget.TextView;

@Override
public class ShowActivity extends AppCompatActivity {


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

        // Richiama l'Intent inizializzato nell'altra Activity ed estrae la stringa
        Intent intent = getIntent();
        String username = intent.getStringExtra(MainActivity.EXTRA_USERNAME);
        String password = intent.getStringExtra(MainActivity.EXTRA_PASSWORD);

        // Prende il layout TextView e lo imposta la stringa come testo
        TextView user = (TextView) findViewById(R.id.textuser);
        TextView pass = (TextView) findViewById(R.id.textpass);
        user.setText(username);
        pass.setText(password);
    }
}