Under66536.java

import java.util.regex.Pattern;

import org.junit.Assert;
import org.junit.Test;

public class Under66536 {
	@Test
	public void under65536() {
		assertUnder65536("0");
		assertUnder65536("065");
		assertUnder65536("004");
		assertUnder65536("0004");
		assertUnder65536("00004");
		assertUnder65536("-1");
		assertUnder65536("650000");
		assertUnder65536("6550123");
		assertUnder65536("601237");
		assertUnder65536("");
		assertUnder65536(null);
		for (int i = 0; i < 700000; i++) {
			assertUnder65536(String.valueOf(i));
		}
	}

	protected void assertUnder65536(String data) {
		Assert.assertEquals(under65536(data), under65536ByRegex(data));

	}

	protected boolean under65536ByRegex(String s) {
		String regex = "\\b0*([1-5]?\\d{1,4}|6553[0-5]|6(55[012]|(5[0-4]|[0-4]\\d)\\d)\\d)\\b";
		return (s != null) && Pattern.matches(regex, s);
	}

	protected boolean under65536(String s) {
		try {
			int i = Integer.parseInt(s);
			return -1 < i && i < 65536;
		} catch (NumberFormatException e) {
		}
		return false;
	}
}