使用 JNDI 进行高级 DNS 查询

import java.util.*;
import javax.naming.directory.*;

public class DNSLookup{
  public static void main(String[] args) {
    try {
      final Hashtable env = new Hashtable();
      //设定DNS Service Provider.
      env.put("java.naming.factory.initial", "com.sun.jndi.dns.DnsContextFactory");
      DirContext dnsContext = new InitialDirContext(env);
      //设定查询类型, 例如A, MX, AAAA, SRV等.
      final String[] types = new String[] {"A"}; 
      //返回查询结果, sun.com的DNS A记录.
      Attributes attrs = dnsContext.getAttributes("sun.com", types);
      System.out.println(attrs);
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}