Android intentButtons

package cc.i420.intent;
 
import android.content.Intent;
import android.net.Uri;
import android.provider.ContactsContract;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
 
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private Intent i;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btnURL = findViewById(R.id.btnURL);
        btnURL.setOnClickListener(this);
        Button btnEmail = findViewById(R.id.btnEmail);
        btnEmail.setOnClickListener(this);
        Button btnCall = findViewById(R.id.btnCall);
        btnCall.setOnClickListener(this);
        Button btnCamera = findViewById(R.id.btnCamera);
        btnCamera.setOnClickListener(this);
        Button btnMap = findViewById(R.id.btnMap);
        btnMap.setOnClickListener(this);
        Button btnGallery = findViewById(R.id.btnGallery);
        btnGallery.setOnClickListener(this);
        Button btnContact = findViewById(R.id.btnContact);
        btnContact.setOnClickListener(this);
        Button btnPlay = findViewById(R.id.btnPlay);
        btnPlay.setOnClickListener(this);
    }
 
    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btnURL:
                i = new Intent(Intent.ACTION_VIEW, Uri.parse("https://www.google.com/"));
                startActivity(i);
                //finish();
                break;
            case R.id.btnEmail:
                i = new Intent(Intent.ACTION_VIEW, Uri.parse("mailto:"));
                startActivity(i);
                //finish();
                break;
            case R.id.btnCall:
                i = new Intent(Intent.ACTION_DIAL);
                startActivity(i);
                //finish();
                break;
            case R.id.btnCamera:
                i = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                startActivity(i);
                //finish();
                break;
            case R.id.btnMap:
                i = new Intent(Intent.ACTION_VIEW);
                i.setPackage("com.google.android.apps.maps");
                startActivity(i);
                //finish();
                break;
            case R.id.btnGallery:
                i = new Intent(Intent.ACTION_PICK);
                i.setType("image/*");
                startActivity(i);
                //finish();
                break;
            case R.id.btnContact:
                i = new Intent(Intent.ACTION_PICK);
                i.setType(ContactsContract.Contacts.CONTENT_TYPE);
                startActivity(i);
                //finish();
                break;
            case R.id.btnPlay:
                i = new Intent(Intent.ACTION_VIEW, Uri.parse("https://play.google.com/"));
                startActivity(i);
                //finish();
                break;
        }
    }
}