通过Java实现IPv6地址简写和全写互相转换方法

Posted 2020-12-15 靠谱的提莫

IPv6地址简写和全写的一种转换方法，入参IPv6地址合法性不做校验。只对合法的IPv6地址进行简写、非简写的转换

 

package com.test;
import com.sun.deploy.util.StringUtils;
import java.util.Arrays;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class transIPv6{
    public static String getFullIPv6(String ipv6){
        //入参为::时，此时全为0
        if (ipv6.equals("::")){
            return "0000:0000:0000:0000:0000:0000:0000:0000";
        }
        //入参已::结尾时，直接在后缀加0
        if (ipv6.endsWith("::")) {
            ipv6 += "0";
        }
        String[] arrs=ipv6.split(":");
        String symbol="::";
        int arrleng=arrs.length;
        System.out.println(arrleng);
        while (arrleng<8){
            symbol+=":";
            arrleng++;
        }
        ipv6=ipv6.replace("::",symbol);
        System.out.println("ipv6:"+ipv6);
        String fullip="";
        for (String ip:ipv6.split(":")){
            while (ip.length()<4){
                ip="0"+ip;
            }
            fullip+=ip+‘:‘;
        }
        return fullip.substring(0,fullip.length()-1);
    }
    public static String getShortIPv6(String ipv6){
        String shortIP="";
        ipv6=getFullIPv6(ipv6);
        String[] arr = ipv6.split(":");
        //去掉每组数据前的0
        for (int i = 0; i < arr.length; i++){
            arr[i] = arr[i].replaceAll("^0{1,3}", "");
        }
        //最长的连续0
        String[] arr2 = arr.clone();
        for (int i = 0; i < arr2.length; i++){
            if (!"0".equals(arr2[i])){
                arr2[i] = "-";
            }
        }
        Pattern pattern = Pattern.compile("0{2,}");
        Matcher matcher = pattern.matcher(StringUtils.join(Arrays.asList(arr2), ""));
        String maxStr= "";
        int start = -1;
        int end = -1;
        while (matcher.find()) {
            if(maxStr.length()<matcher.group().length()) {
                maxStr=matcher.group();
                start = matcher.start();
                end = matcher.end();
            }
        }
        // 组合IPv6简写地址
        if(maxStr.length()>0) {
            for (int i = start; i < end; i++){
                arr[i] = ":";
            }
        }
        shortIP = StringUtils.join(Arrays.asList(arr), ":");
        shortIP= shortIP.replaceAll(":{2,}", "::");
        return shortIP;
    }


    public static void main(String[] args) {
        String ipv6="1::1";
        System.out.println(getFullIPv6(ipv6));
//        System.out.println(getShorIPv6(ipv6));

    }


}