Java BigInteger Calculate getIpv6AddrFromNumber(BigInteger addr)

Description

get Ipv Addr From Number

License

Apache License

Declaration

public static String getIpv6AddrFromNumber(BigInteger addr) 

Method Source Code

//package com.java2s;
/*// w w w  . j  a  v a2  s. co m
 * Copyright 2011,2015 agwlvssainokuni
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.math.BigInteger;

public class Main {

    public static String getIpv6AddrFromNumber(BigInteger addr) {

        String[] field = new String[8];
        BigInteger unit = BigInteger.valueOf(0x10000L);

        BigInteger number = addr;
        for (int i = field.length - 1; i >= 0; i--) {
            BigInteger[] div = number.divideAndRemainder(unit);
            number = div[0];
            field[i] = div[1].toString(16);
        }

        StringBuilder builder = new StringBuilder();
        constructDecompressed(builder, field);
        return builder.toString();
    }

    private static void constructDecompressed(StringBuilder builder, String[] field) {

        appendDecompressed(builder, field[0]);
        for (int i = 1; i < field.length; i++) {
            builder.append(":");
            appendDecompressed(builder, field[i]);
        }
    }

    private static void appendDecompressed(StringBuilder builder, String text) {
        if (isZero(text)) {
            builder.append("0000");
        } else {
            for (int i = text.length(); i < 4; i++) {
                builder.append("0");
            }
            builder.append(text);
        }
    }

    private static boolean isZero(String text) {
        if (text == null) {
            return true;
        } else {
            return text.matches("^0+$");
        }
    }
}

Related

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2. getIntegral(String number, BigInteger def)
3. getInterfaceName(final BigInteger datapathid, final String portName, final Integer vlanId)
4. getIpAddressByBigInteger(BigInteger[] bigs)
5. getIpv4AddrFromNumber(BigInteger addr)
6. getJsonFromBigIntArray(JsonGenerator jg, BigInteger[] array, String pf)
7. getKeyFromBigInteger(final BigInteger value, final int numBytes)
8. getKnownDynamicmacFlowRef(short tableId, BigInteger dpId, long lporTag, String macAddress, long elanTag)
9. getLongAsUnsignedBigInteger(long number)