Null-free Address

NicolaisBasicAddress.java

public class Address {

	// look ma, no comments required

	private final String addressLine;
	private final String city;
	private final Optional<String> postcode;

	// nobody has to look at this constructor to check which parameters are
	// allowed to be null because of course none are!

	public Address(String addressLine, String city, Optional<String> postcode) {
		this.addressLine = requireNonNull(addressLine,
				"The argument 'addressLine' must not be null.");
		this.city = requireNonNull(city,
				"The argument 'city' must not be null.");
		this.postcode = requireNonNull(postcode,
				"The argument 'postcode' must not be null.");
	}

	// of course methods that might not have a result
	// return 'Optional' instead of null

	public static Optional<Address> findAddress(String userInput) {
		// find the address, returning Optional.empty() if not found
	}

	// getters are straight forward and can be generated

	public String getAddressLine() {
		return addressLine;
	}

	public String getCity() {
		return city;
	}

	// look how the field's type matches the getter's type;
	// nice for bean-based code/tools

	public Optional<String> getPostcode() {
		return postcode;
	}

}