Center Items in a dynamic ListView

I have this ListView that takes the Items of a String-arraay that I have defined in my strings.xml, how can I make these items appear in the center of the screen, with the text centered?

<ListView
    android:id="@+id/listaprincipal"
    android:layout_width="match_parent"
    android:layout_height="261dp"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:layout_gravity="center_vertical|center_horizontal"
    android:alwaysDrawnWithCache="false"
    android:animateLayoutChanges="false"
    android:entries="@array/mainlist"
    android:textAlignment="center" />

This is the class that calls the list and where I have defined the action of each item:

listaprincipal=(ListView)findViewById(R.id.listaprincipal);
listaprincipal.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        switch (position){
            case 0:
                Intent intent = new Intent(MainActivity.this,fragmain.class);
                intent.putExtra("posicion","0");
                startActivity(intent);
                break;
            case 1:
                Intent intent1 = new Intent(MainActivity.this,fragmain.class);
                intent1.putExtra("posicion","1");
                startActivity(intent1);
                break;
            case 2:
                Intent intent2 = new Intent(MainActivity.this,fragmain.class);
                intent2.putExtra("posicion","2");
                startActivity(intent2);
                break;
        }
    }
});