如何使用按钮来切换ViewPager中的片段？

<androidx.viewpager.widget.ViewPager
    android:id="@+id/viewPager"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

public class MyPagerAdapter extends FragmentPagerAdapter {
    private List<Fragment> fragments;

    public MyPagerAdapter(FragmentManager fm, List<Fragment> fragments) {
        super(fm);
        this.fragments = fragments;
    }

    @Override
    public Fragment getItem(int position) {
        return fragments.get(position);
    }

    @Override
    public int getCount() {
        return fragments.size();
    }
}

ViewPager viewPager = findViewById(R.id.viewPager);
List<Fragment> fragments = new ArrayList<>();
fragments.add(new Fragment1());
fragments.add(new Fragment2());
fragments.add(new Fragment3());

MyPagerAdapter adapter = new MyPagerAdapter(getSupportFragmentManager(), fragments);
viewPager.setAdapter(adapter);

Button button1 = findViewById(R.id.button1);
Button button2 = findViewById(R.id.button2);
Button button3 = findViewById(R.id.button3);

button1.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        viewPager.setCurrentItem(0);
    }
});

button2.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        viewPager.setCurrentItem(1);
    }
});

button3.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        viewPager.setCurrentItem(2);
    }
});