使用通配符IP地址獲取域名

Question

我正在嘗試編寫一個類，該類將從/ etc / hosts文件中的IP地址返回域名。 例如，我知道Google擁有的IP地址塊是74.125.0.0 - 74.125.255.255並且在我的主機文件中；

74.125.24.155   Google
74.125.24.101   Google
74.125.24.102   Google
74.125.24.132   Google
74.125.24.113   Google
74.125.24.84   Google

我編寫了一段簡單的代碼，它將查找主機文件並搜索相應IP地址的名稱。 這是代碼；

String destination = "74.125.24.84";
InetAddress address = InetAddress.getByName(destination);
String resolvedHost = address.getHostName();
System.out.println("Translated " + destination + " to host name " + resolvedHost);

這將返回以下Translated 74.125.24.84 to host name Google 。 然后我嘗試；

String destination = "74.125.24.*";
InetAddress address = InetAddress.getByName(destination);
String resolvedHost = address.getHostName();
System.out.println("Translated " + destination + " to host name " + resolvedHost);

但是得到以下錯誤響應；

java.net.UnknownHostException: 74.125.24.*
at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
at java.net.InetAddress$1.lookupAllHostAddr(Unknown Source)
at java.net.InetAddress.getAddressesFromNameService(Unknown Source)
at java.net.InetAddress.getAllByName0(Unknown Source)
at java.net.InetAddress.getAllByName(Unknown Source)
at java.net.InetAddress.getAllByName(Unknown Source)
at java.net.InetAddress.getByName(Unknown Source)
at IPToDomainName.main(IPToDomainName.java:12)

有沒有一種方法可以使用通配符表示Google的IP地址？

Answer 1

你可以遍歷它嗎？

for (int i=0;i<=255;i++) {
    String destination = "74.125.24." + i;
    InetAddress address = InetAddress.getByName(destination);

    if (address == null) // Or any exception.
         continue;

    String resolvedHost = address.getHostName();

    System.out.println("Translated " + destination + " to host name " + resolvedHost);
}