java IPV6、IPV4地址与BigInteger互相转化

由于项目的需要，需要把 IPV6、IPV4地址转化为BigInteger，也需要将BigInteger转化为 IPV6、IPV4地址。于是上网查找资料。发现网上有一个IpConvert类：于是拷贝下来在项目中应用。
IpConvert的源码如下：

import java.math.BigInteger;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Arrays;

/**
 * IP转换工具
 * 
 * @author Takamachi660
 * 
 */
public final class IpConvert {
	/**
	 * 防止被实例化
	 */
	private IpConvert() {
	}

	/**
	 * 将字符串形式的ip地址转换为BigInteger
	 * 
	 * @param ipInString
	 *            字符串形式的ip地址
	 * @return 整数形式的ip地址
	 */
	public static BigInteger stringToBigInt(String ipInString) {
		ipInString = ipInString.replace(" ", "");
		byte[] bytes;
		if (ipInString.contains(":"))
			bytes = ipv6ToBytes(ipInString);
		else
			bytes = ipv4ToBytes(ipInString);
		return new BigInteger(bytes);
	}

	/**
	 * 将整数形式的ip地址转换为字符串形式
	 * 
	 * @param ipInBigInt
	 *            整数形式的ip地址
	 * @return 字符串形式的ip地址
	 */
	public static String bigIntToString(BigInteger ipInBigInt) {
		byte[] bytes = ipInBigInt.toByteArray();
		byte[] unsignedBytes = Arrays.copyOfRange(bytes, 1, bytes.length);
		// 去除符号位
		try {
			String ip = InetAddress.getByAddress(unsignedBytes).toString();
			return ip.substring(ip.indexOf('/') + 1).trim();
		} catch (UnknownHostException e) {
			throw new RuntimeException(e);
		}
	}

	/**
	 * ipv6地址转有符号byte[17]
	 */
	private static byte[] ipv6ToBytes(String ipv6) {
		byte[] ret = new byte[17];
		ret[0] = 0;
		int ib = 16;
		boolean comFlag = false;// ipv4混合模式标记
		if (ipv6.startsWith(":"))// 去掉开头的冒号
			ipv6 = ipv6.substring(1);
		String groups[] = ipv6.split(":");
		for (int ig = groups.length - 1; ig > -1; ig--) {// 反向扫描
			if (groups[ig].contains(".")) {
				// 出现ipv4混合模式
				byte[] temp = ipv4ToBytes(groups[ig]);
				ret[ib--] = temp[4];
				ret[ib--] = temp[3];
				ret[ib--] = temp[2];
				ret[ib--] = temp[1];
				comFlag = true;
			} else if ("".equals(groups[ig])) {
				// 出现零长度压缩,计算缺少的组数
				int zlg = 9 - (groups.length + (comFlag ? 1 : 0));
				while (zlg-- > 0) {// 将这些组置0
					ret[ib--] = 0;
					ret[ib--] = 0;
				}
			} else {
				int temp = Integer.parseInt(groups[ig], 16);
				ret[ib--] = (byte) temp;
				ret[ib--] = (byte) (temp >> 8);
			}
		}
		return ret;
	}

	/**
	 * ipv4地址转有符号byte[5]
	 */
	private static byte[] ipv4ToBytes(String ipv4) {
		byte[] ret = new byte[5];
		ret[0] = 0;
		// 先找到IP地址字符串中.的位置
		int position1 = ipv4.indexOf(".");
		int position2 = ipv4.indexOf(".", position1 + 1);
		int position3 = ipv4.indexOf(".", position2 + 1);
		// 将每个.之间的字符串转换成整型
		ret[1] = (byte) Integer.parseInt(ipv4.substring(0, position1));
		ret[2] = (byte) Integer.parseInt(ipv4.substring(position1 + 1,
				position2));
		ret[3] = (byte) Integer.parseInt(ipv4.substring(position2 + 1,
				position3));
		ret[4] = (byte) Integer.parseInt(ipv4.substring(position3 + 1));
		return ret;
	}

	public static void main(String[] args) {
		System.out.println(stringToBigInt("10.36.65.22"));
		System.out.println(bigIntToString(stringToBigInt("10.36.65.22")));
	}
}

 但是，在测试的时候发现10段的ip地址的BigInteger 形式无法转为字符串，经过一番测试将程序改造如下：

import java.math.BigInteger;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Arrays;

/**
 * IP转换工具
 * 
 * @author Takamachi660
 * 
 */
public final class IpConvert {
	/**
	 * 防止被实例化
	 */
	private IpConvert() {
	}

	/**
	 * 将字符串形式的ip地址转换为BigInteger
	 * 
	 * @param ipInString
	 *            字符串形式的ip地址
	 * @return 整数形式的ip地址
	 */
	public static BigInteger stringToBigInt(String ipInString) {
		ipInString = ipInString.replace(" ", "");
		byte[] bytes;
		if (ipInString.contains(":"))
			bytes = ipv6ToBytes(ipInString);
		else
			bytes = ipv4ToBytes(ipInString);
		return new BigInteger(bytes);
	}

	/**
	 * 将整数形式的ip地址转换为字符串形式
	 * 
	 * @param ipInBigInt
	 *            整数形式的ip地址
	 * @return 字符串形式的ip地址
	 */
	public static String bigIntToString(BigInteger ipInBigInt) {
		byte[] bytes = ipInBigInt.toByteArray();
		byte[] unsignedBytes = Arrays.copyOfRange(bytes, 1, bytes.length);
		if (bytes.length == 4 || bytes.length == 16) {
			unsignedBytes = bytes;
		}
		// 去除符号位
		try {
			String ip = InetAddress.getByAddress(unsignedBytes).toString();
			return ip.substring(ip.indexOf('/') + 1).trim();
		} catch (UnknownHostException e) {
			throw new RuntimeException(e);
		}
	}

	/**
	 * ipv6地址转有符号byte[17]
	 */
	private static byte[] ipv6ToBytes(String ipv6) {
		byte[] ret = new byte[17];
		ret[0] = 0;
		int ib = 16;
		boolean comFlag = false;// ipv4混合模式标记
		if (ipv6.startsWith(":"))// 去掉开头的冒号
			ipv6 = ipv6.substring(1);
		String groups[] = ipv6.split(":");
		for (int ig = groups.length - 1; ig > -1; ig--) {// 反向扫描
			if (groups[ig].contains(".")) {
				// 出现ipv4混合模式
				byte[] temp = ipv4ToBytes(groups[ig]);
				ret[ib--] = temp[4];
				ret[ib--] = temp[3];
				ret[ib--] = temp[2];
				ret[ib--] = temp[1];
				comFlag = true;
			} else if ("".equals(groups[ig])) {
				// 出现零长度压缩,计算缺少的组数
				int zlg = 9 - (groups.length + (comFlag ? 1 : 0));
				while (zlg-- > 0) {// 将这些组置0
					ret[ib--] = 0;
					ret[ib--] = 0;
				}
			} else {
				int temp = Integer.parseInt(groups[ig], 16);
				ret[ib--] = (byte) temp;
				ret[ib--] = (byte) (temp >> 8);
			}
		}
		return ret;
	}

	/**
	 * ipv4地址转有符号byte[5]
	 */
	private static byte[] ipv4ToBytes(String ipv4) {
		byte[] ret = new byte[5];
		ret[0] = 0;
		// 先找到IP地址字符串中.的位置
		int position1 = ipv4.indexOf(".");
		int position2 = ipv4.indexOf(".", position1 + 1);
		int position3 = ipv4.indexOf(".", position2 + 1);
		// 将每个.之间的字符串转换成整型
		ret[1] = (byte) Integer.parseInt(ipv4.substring(0, position1));
		ret[2] = (byte) Integer.parseInt(ipv4.substring(position1 + 1,
				position2));
		ret[3] = (byte) Integer.parseInt(ipv4.substring(position2 + 1,
				position3));
		ret[4] = (byte) Integer.parseInt(ipv4.substring(position3 + 1));
		return ret;
	}

	public static void main(String[] args) {
		System.out.println(stringToBigInt("10.36.65.22"));
		System.out.println(bigIntToString(stringToBigInt("10.36.65.22")));
		System.out.println(stringToBigInt("fe80::8984:de33:85aa:5b81"));
		System.out.println(bigIntToString(new BigInteger(
				"338288524927261089663928186234336861057")));
	}
}

 改造以后，能够适用于10段、172段、192段、127段等绝大多数的BigInteger 形式转为字符串。其中以下代码是我增加的：

if (bytes.length == 4 || bytes.length == 16) {

unsignedBytes = bytes;

 

}