OnClickListener cannot be resolved to a type

I'm diving into Java (this is day 1) and I'm trying to create a button that will trigger a notification when I click it...

This code is based off of the notification documentation here, and UI events documentation here

package com.example.contactwidget;

import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.widget.Button;

public class Con开发者_StackOverflow社区tactWidget extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Button calc1 = (Button) findViewById(R.id.calc_button_1);
        calc1.setOnClickListener(buttonListener);

        setContentView(R.layout.main);
    }

    private static final int HELLO_ID = 1;

    //Error: OnClickListener cannot be resolved to a type
    private OnClickListener buttonListener = new OnClickListener() {
        public void onClick (View v) {
            String ns = Context.NOTIFICATION_SERVICE;
            NotificationManager mNotificationManager = (NotificationManager) getSystemService(ns);

            int icon = R.drawable.icon;
            CharSequence ticketBrief = "Button Pressed Brief";
            CharSequence ticketTitle = "Button pressed";
            CharSequence ticketText = "You pressed button 1";
            long when = System.currentTimeMillis();

            Notification notification = new Notification(icon, ticketBrief, when);

            Intent notificationIntent = new Intent(this, ContactWidget.class);
            PendingIntent contentIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0);

            notification.setLatestEventInfo(getApplicationContext(), ticketTitle, ticketText, contentIntent);

            mNotificationManager.notify(HELLO_ID, notification);
        }
    }
}

I'm running into a problem: OnClickListener cannot be resolved to a type. The problem here is that I don't see any problems with my code in relation to the example I'm using

Add this import:

import android.view.View.OnClickListener;

If you are using Eclipse, you can use Ctrl+Shift+O to make it import those clases or interfaces automagically.

Make sure you have both these imports:

import android.view.View;
import android.view.View.OnClickListener;

setContentView(R.layout.main);

Should be above the button declaration, just below

super.onCreate(savedInstanceState);