How to make an Android device vibrate? with different frequency?

I wrote an Android application. Now, I want to make the device vibrate when a certain action occurs. How can I do this?

Try:

import android.os.Vibrator;
...
Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
// Vibrate for 500 milliseconds
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
    v.vibrate(VibrationEffect.createOneShot(500, VibrationEffect.DEFAULT_AMPLITUDE));
} else {
    //deprecated in API 26 
    v.vibrate(500);
}

Note:

Don't forget to include permission in AndroidManifest.xml file:

<uses-permission android:name="android.permission.VIBRATE"/>

Grant Vibration Permission

Before you start implementing any vibration code, you have to give your application the permission to vibrate:

<uses-permission android:name="android.permission.VIBRATE"/>

Make sure to include this line in your AndroidManifest.xml file.

Import the Vibration Library

Most IDEs will do this for you, but here is the import statement if yours doesn't:

 import android.os.Vibrator;

Make sure this in the activity where you want the vibration to occur.

How to Vibrate for a Given Time

In most circumstances, you'll be wanting to vibrate the device for a short, predetermined amount of time. You can achieve this by using the vibrate(long milliseconds) method. Here is a quick example:

// Get instance of Vibrator from current Context
Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);

// Vibrate for 400 milliseconds
v.vibrate(400);

That's it, simple!

How to Vibrate Indefinitely

It may be the case that you want the device to continue vibrating indefinitely. For this, we use the vibrate(long[] pattern, int repeat) method:

// Get instance of Vibrator from current Context
Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);

// Start without a delay
// Vibrate for 100 milliseconds
// Sleep for 1000 milliseconds
long[] pattern = {0, 100, 1000};

// The '0' here means to repeat indefinitely
// '0' is actually the index at which the pattern keeps repeating from (the start)
// To repeat the pattern from any other point, you could increase the index, e.g. '1'
v.vibrate(pattern, 0);

When you're ready to stop the vibration, just call the cancel() method:

v.cancel();

How to use Vibration Patterns

If you want a more bespoke vibration, you can attempt to create your own vibration patterns:

// Get instance of Vibrator from current Context
Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);

// Start without a delay
// Each element then alternates between vibrate, sleep, vibrate, sleep...
long[] pattern = {0, 100, 1000, 300, 200, 100, 500, 200, 100};

// The '-1' here means to vibrate once, as '-1' is out of bounds in the pattern array
v.vibrate(pattern, -1);

More Complex Vibrations

There are multiple SDKs that offer a more comprehensive range of haptic feedback. One that I use for special effects is Immersion's Haptic Development Platform for Android.

Troubleshooting

If your device won't vibrate, first make sure that it can vibrate:

// Get instance of Vibrator from current Context
Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);

// Output yes if can vibrate, no otherwise
if (v.hasVibrator()) {
    Log.v("Can Vibrate", "YES");
} else {
    Log.v("Can Vibrate", "NO");
}

Secondly, please ensure that you've given your application the permission to vibrate! Refer back to the first point.

Update 2017 vibrate(interval) method is deprecated with Android-O(API 8.0)

To support all Android versions use this method.

// Vibrate for 150 milliseconds
private void shakeItBaby() {
    if (Build.VERSION.SDK_INT >= 26) {
        ((Vibrator) getSystemService(VIBRATOR_SERVICE)).vibrate(VibrationEffect.createOneShot(150, VibrationEffect.DEFAULT_AMPLITUDE));
    } else {
        ((Vibrator) getSystemService(VIBRATOR_SERVICE)).vibrate(150);
    }
}

Kotlin:

// Vibrate for 150 milliseconds
private fun shakeItBaby(context: Context) {
    if (Build.VERSION.SDK_INT >= 26) {
        (context.getSystemService(VIBRATOR_SERVICE) as Vibrator).vibrate(VibrationEffect.createOneShot(150, VibrationEffect.DEFAULT_AMPLITUDE))
    } else {
        (context.getSystemService(VIBRATOR_SERVICE) as Vibrator).vibrate(150)
    }
}