解析IP范围以获取IP列表

Question

是否有任何Java API可以将IP范围字符串转换为IP列表？

IP范围的语法是在范围部分之间划线，例如：

  

117.211.141-147.20-218

Answer 1

这种方法有点冗长，但效果很好。

public static List<String> getListFromRange(String ip) { //117.211.141-147.20-218
    String[] segments = ip.split("\\.");    //split into 4 segments
    int seg1Lower;
    int seg1Upper;
    int seg2Lower;
    int seg2Upper;
    int seg3Lower;
    int seg3Upper;
    int seg4Lower;
    int seg4Upper;

    // get lower and upper bound of 1st segment
    String[] seg1 = segments[0].split("-");
    if (seg1.length == 1) {
        seg1Lower = Integer.parseInt(seg1[0]);
        seg1Upper = Integer.parseInt(seg1[0]);
    } else {
        seg1Lower = Integer.parseInt(seg1[0]);
        seg1Upper = Integer.parseInt(seg1[1]);
    }

    // get lower and upper bound of 2nd segment
    String[] seg2 = segments[1].split("-");
    if (seg2.length == 1) {
        seg2Lower = Integer.parseInt(seg2[0]);
        seg2Upper = Integer.parseInt(seg2[0]);
    } else {
        seg2Lower = Integer.parseInt(seg2[0]);
        seg2Upper = Integer.parseInt(seg2[1]);
    }

    // get lower and upper bound of 3rd segment
    String[] seg3 = segments[2].split("-");
    if (seg3.length == 1) {
        seg3Lower = Integer.parseInt(seg3[0]);
        seg3Upper = Integer.parseInt(seg3[0]);
    } else {
        seg3Lower = Integer.parseInt(seg3[0]);
        seg3Upper = Integer.parseInt(seg3[1]);
    }

    // get lower and upper bound of 4th segment
    String[] seg4 = segments[3].split("-");
    if (seg4.length == 1) {
        seg4Lower = Integer.parseInt(seg4[0]);
        seg4Upper = Integer.parseInt(seg4[0]);
    } else {
        seg4Lower = Integer.parseInt(seg4[0]);
        seg4Upper = Integer.parseInt(seg4[1]);
    }

    //generate all IPs
    List<String> IPs = new ArrayList<>();
    for (int i = seg1Lower; i <= seg1Upper; i++) {
        for (int j = seg2Lower; j <= seg2Upper; j++) {
            for (int k = seg3Lower; k <= seg3Upper; k++) {
                for (int l = seg4Lower; l <= seg4Upper; l++) {
                    IPs.add(i + "." + j + "." + k + "." + l);
                }
            }
        }
    }

    return IPs;
} 

以下是main()方法

public static void main(String[] args) {
    List<String> IPs = getListFromRange("117.211.141-147.20-218");
    for (String IP : IPs) {
        System.out.println(IP);
    }
}