Find the address class and address type from the IP address with Java [No. 2 decoction]

at first

I decided to use a cloud server, and thankfully I got a global IP. In order to separate the processing between the in-house PC (private IP) and the cloud server (global IP), it is now possible to determine the address class and private IP from the IP.

(Original story) Obtaining the address class and address type from the IP address with Java

(reference) IP Address-Wikipedia

Implementation

IPAddressInfo.java

public class IPAddressInfo {

	public enum AddressClass{
		ClassA(128) {
			@Override
			protected boolean isPrivate(int first, int second) {
				return first == 10;
			}
		},
		ClassB(128 + 64) {
			@Override
			protected boolean isPrivate(int first, int second) {
				return first == 172 && (16 <= second && second <= 31);
			}
		},
		ClassC(128 + 64 + 32) {
			@Override
			protected boolean isPrivate(int first, int second) {
				return first == 192 && second == 168;
			}
		},
		ClassD(128 + 64 + 32 + 16) {
			@Override
			protected boolean isPrivate(int first, int second) {
				return false;
			}
		},
		ClassE(256) {
			@Override
			protected boolean isPrivate(int first, int second) {
				return false;
			}
		},;

		private final int outOfNo;

		/**
		 *Five address classes of IP addresses.
		 * @param outOfNo The first IP of the following address class
		 */
		private AddressClass(int outOfNo){
			this.outOfNo = outOfNo;
		}

		protected abstract boolean isPrivate(int first, int second);
	}

	public AddressClass getAddressClass(int first){
		return  Arrays.stream(AddressClass.values()).filter(p -> first < p.outOfNo).findFirst().orElseThrow(() -> new IllegalArgumentException("Not IP:" + first));
	}

	public AddressClass getAddressClass(String ip){
		List<String> addressList = Arrays.asList(ip.split("\\."));
		return getAddressClass(Integer.valueOf(addressList.get(0)));
	}

	public boolean isPrivate(String ip){
		List<String> addressList = Arrays.asList(ip.split("\\."));
		int first = Integer.valueOf(addressList.get(0));
		int second = Integer.valueOf(addressList.get(1));
		return getAddressClass(first).isPrivate(first, second);
	}
}

test

IPAddressInfo.java

	@Test
	public void getAddressClass(){
		assertThat(getAddressClass("0.0.0.0"), is(AddressClass.ClassA));
		assertThat(getAddressClass("10.0.0.0"), is(AddressClass.ClassA));
		assertThat(getAddressClass("10.255.255.255"), is(AddressClass.ClassA));
		assertThat(getAddressClass("127.255.255.255"), is(AddressClass.ClassA));

		assertThat(getAddressClass("128.0.0.0"), is(AddressClass.ClassB));
		assertThat(getAddressClass("172.16.0.0"), is(AddressClass.ClassB));
		assertThat(getAddressClass("172.31.255.255"), is(AddressClass.ClassB));
		assertThat(getAddressClass("191.255.255.255"), is(AddressClass.ClassB));

		assertThat(getAddressClass("192.0.0.0"), is(AddressClass.ClassC));
		assertThat(getAddressClass("192.168.0.0"), is(AddressClass.ClassC));
		assertThat(getAddressClass("192.168.255.255"), is(AddressClass.ClassC));
		assertThat(getAddressClass("223.255.255.255"), is(AddressClass.ClassC));

		assertThat(getAddressClass("224.0.0.0"), is(AddressClass.ClassD));
		assertThat(getAddressClass("239.255.255.255"), is(AddressClass.ClassD));

		assertThat(getAddressClass("240.0.0.0"), is(AddressClass.ClassE));
		assertThat(getAddressClass("255.255.255.255"), is(AddressClass.ClassE));
	}

	@Test
	public void isPrivate(){
		assertThat(isPrivate("0.0.0.0"), is(false));
		assertThat(isPrivate("10.0.0.0"), is(true));
		assertThat(isPrivate("10.255.255.255"), is(true));
		assertThat(isPrivate("127.255.255.255"), is(false));

		assertThat(isPrivate("128.0.0.0"), is(false));
		assertThat(isPrivate("172.16.0.0"), is(true));
		assertThat(isPrivate("172.31.255.255"), is(true));
		assertThat(isPrivate("191.255.255.255"), is(false));

		assertThat(isPrivate("192.0.0.0"), is(false));
		assertThat(isPrivate("192.168.0.0"), is(true));
		assertThat(isPrivate("192.168.255.255"), is(true));
		assertThat(isPrivate("223.255.255.255"), is(false));

		assertThat(isPrivate("224.0.0.0"), is(false));
		assertThat(isPrivate("239.255.255.255"), is(false));

		assertThat(isPrivate("240.0.0.0"), is(false));
		assertThat(isPrivate("255.255.255.255"), is(false));
	}

	@Test(expected=IllegalArgumentException.class)
	public void error(){
		getAddressClass("256.255.255.255");
	}