Package de.measite.minidns

Class Client

  • public class Client
extends java.lang.Object
    A minimal DNS client for SRV/A/AAAA/NS and CNAME lookups, with IDN support. This circumvents the missing javax.naming package on android.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected int bufferSize
      The buffer size for dns replies.
      protected DNSCache cache
      The internal DNS cache.
      private static java.util.logging.Logger LOGGER  
      protected java.util.Random random
      The internal random class for sequence generation.
      protected int timeout
      DNS timeout.

    • Constructor Summary

      Constructors 
      Constructor Description
      Client()
      Create a new DNS client without any caching.
      Client​(DNSCache cache)
      Create a new DNS client with the given DNS cache.
      Client​(java.util.Map<Question,​DNSMessage> cache)  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.String[] findDNS()
      Retrieve a list of currently configured DNS servers.
      protected java.lang.String[] findDNSByExec()
      Try to retrieve the list of dns server by executing getprop.
      protected java.lang.String[] findDNSByReflection()
      Try to retrieve the list of dns server by calling SystemProperties.
      int getTimeout()
      Retrieve the current dns query timeout, in milliseconds.
      DNSMessage query​(Question q)
      Query the system DNS server for one entry.
      DNSMessage query​(Question q, java.lang.String host)
      Query a specific server for one entry.
      DNSMessage query​(Question q, java.lang.String host, int port)
      Query a specific server for one entry.
      DNSMessage query​(java.lang.String name, Record.TYPE type)
      Query the system nameservers for a single entry of the class IN (which is used for MX, SRV, A, AAAA and most other RRs).
      DNSMessage query​(java.lang.String name, Record.TYPE type, Record.CLASS clazz)
      Query the system nameservers for a single entry of any class.
      DNSMessage query​(java.lang.String name, Record.TYPE type, Record.CLASS clazz, java.lang.String host)
      Query a nameserver for a single entry.
      DNSMessage query​(java.lang.String name, Record.TYPE type, Record.CLASS clazz, java.lang.String host, int port)
      Query a nameserver for a single entry.
      void setTimeout​(int timeout)
      Change the dns query timeout for all future queries.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • LOGGER

        private static final java.util.logging.Logger LOGGER

      • random

        protected java.util.Random random
        The internal random class for sequence generation.

      • bufferSize

        protected int bufferSize
        The buffer size for dns replies.

      • timeout

        protected int timeout
        DNS timeout.

      • cache

        protected DNSCache cache
        The internal DNS cache.

    • Constructor Detail

      • Client

        public Client​(DNSCache cache)
        Create a new DNS client with the given DNS cache.
        Parameters:
        cache - The backend DNS cache.

      • Client

        public Client()
        Create a new DNS client without any caching.

    • Method Detail

      • getTimeout

        public int getTimeout()
        Retrieve the current dns query timeout, in milliseconds.
        Returns:
        the current dns query timeout in milliseconds.

      • setTimeout

        public void setTimeout​(int timeout)
        Change the dns query timeout for all future queries. The timeout must be specified in milliseconds.
        Parameters:
        timeout - new dns query timeout in milliseconds.

      • query

        public DNSMessage query​(java.lang.String name,
                        Record.TYPE type,
                        Record.CLASS clazz,
                        java.lang.String host,
                        int port)
                 throws java.io.IOException
        Query a nameserver for a single entry.
        Parameters:
        name - The DNS name to request.
        type - The DNS type to request (SRV, A, AAAA, ...).
        clazz - The class of the request (usually IN for Internet).
        host - The DNS server host.
        port - The DNS server port.
        Returns:
        The response (or null on timeout / failure).
        Throws:
        java.io.IOException - On IO Errors.

      • query

        public DNSMessage query​(java.lang.String name,
                        Record.TYPE type,
                        Record.CLASS clazz,
                        java.lang.String host)
                 throws java.io.IOException
        Query a nameserver for a single entry.
        Parameters:
        name - The DNS name to request.
        type - The DNS type to request (SRV, A, AAAA, ...).
        clazz - The class of the request (usually IN for Internet).
        host - The DNS server host.
        Returns:
        The response (or null on timeout / failure).
        Throws:
        java.io.IOException - On IO Errors.

      • query

        public DNSMessage query​(java.lang.String name,
                        Record.TYPE type,
                        Record.CLASS clazz)
        Query the system nameservers for a single entry of any class. This can be used to determine the name server version, if name is version.bind, type is TYPE.TXT and clazz is CLASS.CH.
        Parameters:
        name - The DNS name to request.
        type - The DNS type to request (SRV, A, AAAA, ...).
        clazz - The class of the request (usually IN for Internet).
        Returns:
        The response (or null on timeout/error).

      • query

        public DNSMessage query​(java.lang.String name,
                        Record.TYPE type)
        Query the system nameservers for a single entry of the class IN (which is used for MX, SRV, A, AAAA and most other RRs).
        Parameters:
        name - The DNS name to request.
        type - The DNS type to request (SRV, A, AAAA, ...).
        Returns:
        The response (or null on timeout/error).

      • query

        public DNSMessage query​(Question q,
                        java.lang.String host)
                 throws java.io.IOException
        Query a specific server for one entry.
        Parameters:
        q - The question section of the DNS query.
        host - The dns server host.
        Returns:
        The response (or null on timeout/error).
        Throws:
        java.io.IOException - On IOErrors.

      • query

        public DNSMessage query​(Question q,
                        java.lang.String host,
                        int port)
                 throws java.io.IOException
        Query a specific server for one entry.
        Parameters:
        q - The question section of the DNS query.
        host - The dns server host.
        port - the dns port.
        Returns:
        The response (or null on timeout/error).
        Throws:
        java.io.IOException - On IOErrors.

      • query

        public DNSMessage query​(Question q)
        Query the system DNS server for one entry.
        Parameters:
        q - The question section of the DNS query.
        Returns:
        The response (or null on timeout/error).

      • findDNS

        public java.lang.String[] findDNS()
        Retrieve a list of currently configured DNS servers.
        Returns:
        The server array.

      • findDNSByExec

        protected java.lang.String[] findDNSByExec()
        Try to retrieve the list of dns server by executing getprop.
        Returns:
        Array of servers, or null on failure.

      • findDNSByReflection

        protected java.lang.String[] findDNSByReflection()
        Try to retrieve the list of dns server by calling SystemProperties.
        Returns:
        Array of servers, or null on failure.