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;
}