Definition: The facade pattern creates one simple interface to replace a set of one or more interfaces, which might be quite complex.

Usage: Use the facade pattern to simplify a complicated subsystem.

Example

class RandomUtil {
	byte getRandomElement(final byte[] array) {
		return array[getRandomIndex(array)];
	}

	char getRandomElement(final char[] array) {
		return array[getRandomIndex(array)];
	}

	double getRandomElement(final double[] array) {
		return array[getRandomIndex(array)];
	}

	float getRandomElement(final float[] array) {
		return array[getRandomIndex(array)];
	}

	int getRandomElement(final int[] array) {
		return array[getRandomIndex(array)];
	}

	long getRandomElement(final long[] array) {
		return array[getRandomIndex(array)];
	}

	short getRandomElement(final short[] array) {
		return array[getRandomIndex(array)];
	}

	Object getRandomElement(final Object[] array) {
		return array[getRandomIndex(array)];
	}

	int getRandomIndex(final byte[] array) {
		return randomNumberGenerator.nextInt(array.length);
	}

	int getRandomIndex(final char[] array) {
		return randomNumberGenerator.nextInt(array.length);
	}

	int getRandomIndex(final double[] array) {
		return randomNumberGenerator.nextInt(array.length);
	}

	int getRandomIndex(final float[] array) {
		return randomNumberGenerator.nextInt(array.length);
	}

	int getRandomIndex(final int[] array) {
		return randomNumberGenerator.nextInt(array.length);
	}

	int getRandomIndex(final long[] array) {
		return randomNumberGenerator.nextInt(array.length);
	}

	int getRandomIndex(final short[] array) {
		return randomNumberGenerator.nextInt(array.length);
	}

	int getRandomIndex(final Object[] array) {
		return randomNumberGenerator.nextInt(array.length);
	}

	Random randomNumberGenerator = new Random();
}

This class simplifies access to the class Random. Essentially, it saves a few keypresses when writing code that gets random elements from arrays. The real world version of this class included additional methods for getting random booleans, ints, longs, etc.