ipaddresstool.java

冒险岛私服Java版服务端(Odinms)源代码。学习JAVA开发的朋友

package net.sf.odinms.tools;

/**
 * Provides a class with tools for working with IP addresses, in both strings
 * and as long integers.
 * 
 * @author Nol888
 * @version 0.1
 */
public class IPAddressTool {
	/**
	 * Dummy constructor for static classes.
	 */
	private IPAddressTool() {
	}

	/**
	 * Converts a dotted-quad IP (<code>127.0.0.1</code>) and turns it into
	 * a long integer IP.
	 * 
	 * @param dottedQuad The IP address in dotted-quad form.
	 * @return The IP as a long integer.
	 * @throws RuntimeException
	 */
	public static long dottedQuadToLong(String dottedQuad) throws RuntimeException {
		String[] quads = dottedQuad.split("\\.");
		if (quads.length != 4) {
			throw new RuntimeException("Invalid IP Address format.");
		}

		long ipAddress = 0;

		for (int i = 0; i < 4; i++) {
			int quad = Integer.parseInt(quads[i]);
			ipAddress += (long) (quad % 256) * (long) Math.pow(256, (double) (4 - i));
		}

		return ipAddress;
	}

	/**
	 * Converts a long integer IP into a dotted-quad IP.
	 * 
	 * @param longIP The IP as a long integer.
	 * @return The IP as a dotted-quad string.
	 * @throws RuntimeException
	 */
	public static String longToDottedQuad(long longIP) throws RuntimeException {
		StringBuilder ipAddress = new StringBuilder();

		for (int i = 0; i < 4; i++) {
			int quad = (int) (longIP / (long) Math.pow(256, (double) (4 - i)));
			longIP -= (long) quad * (long) Math.pow(256, (double) (4 - i));
			if (i > 0) {
				ipAddress.append(".");
			}
			if (quad > 255) {
				throw new RuntimeException("Invalid long IP address.");
			}
			ipAddress.append(quad);
		}

		return ipAddress.toString();
	}
}