How to make an action after a button click?

I've been looking all over the forum for answers but no matter how many times I modify it, there's always an error that comes up. it says "Main activity must be abstract or implement abstract method onClick(View) in onClickListener" Here is my code.

import android.app.Activity;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.view.View;


public class MainActivity extends ActionBarActivity implements OnClickListener
{
  /*
   *Everything here is Array Strings and other variables that are unrelated to the problem.
   * I chose not to post them because they would have tooken to much unnecessary space
   */
};

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Button button1, button2, button3;
    button1 = ((Button) findViewById(R.id.button1));
    button2 = ((Button) findViewById(R.id.button2));
    button3 = ((Button) findViewById(R.id.button3));
    button1.setOnClickListener(this);
    button2.setOnClickListener(this);
    button3.setOnClickListener(this);

         OnClickListener onClickListener = new OnClickListener() {
        @Override
        public void onClick( View v) {
            switch (v.getId()) {
                case R.id.button1:
                    //DO something
                    break;
                case R.id.button2:
                    //DO something
                    break;
                case R.id.button3:
                    //DO something
                    break;
            }
        }

};
}