Brian Wellington (firstname.lastname@example.org) March 12, 2004
dnsjava is an implementation of DNS in Java. It supports all defined record types (including the DNSSEC types), and unknown types. It can be used for queries, zone transfers, and dynamic updates. It includes a cache which can be used by clients, and an authoritative only server. It supports TSIG authenticated messages, partial DNSSEC verification, and EDNS0. It is fully thread safe. It can be used to replace the native DNS support in Java.
dnsjava was started as an excuse to learn Java. It was useful for testing new features in BIND without rewriting the C resolver. It was then cleaned up and extended in order to be used as a testing framework for DNS interoperability testing. The high level API and caching resolver were added to make it useful to a wider audience. The authoritative only server was added as proof of concept.
Run 'ant' from the toplevel directory to build dnsjava (a Makefile is also provided, but does not have all of the features of the ant script). JDK 1.4 or higher is required.
To compile name service provider support (org.xbill.DNS.spi), run 'ant spi'.
Replacing the standard Java DNS functionality:
Beginning with Java 1.4, service providers can be loaded at runtime. To load the dnsjava service provider, build it as explained above and set the system property:
This instructs the JVM to use the dnsjava service provide for DNS at the highest priority.
Matt Rutherford email@example.com contributed a number of unit tests, which are in the tests subdirectory. The hierarchy under tests mirrors the org.xbill.DNS classes. To build the unit tests, run 'ant compile_tests', and to run then, run 'ant run_tests'. The tests require JUnit (http://www.junit.org) to be installed.
Some high-level test programs are in org/xbill/DNS/tests.
There's no standard way to determine what the local nameserver or DNS search path is at runtime from within the JVM. dnsjava attempts several methods until one succeeds.
- The properties 'dns.server' and 'dns.search' (comma delimited lists) are checked. The servers can either be IP addresses or hostnames (which are resolved using Java's built in DNS support).
- The sun.net.dns.ResolverConfiguration class is queried.
- On Unix, /etc/resolv.conf is parsed.
- On Windows, ipconfig/winipcfg is called and its output parsed. This may fail for non-English versions on Windows.
- As a last resort, "localhost" is used as the nameserver, and the search path is empty.
The underlying platform must use an ASCII encoding of characters. This means that dnsjava will not work on OS/390, for example.
Javadoc documentation is provided in the doc/ subdirectory of binary distributions, and can be built with 'ant docs'.
dnsjava is placed under the BSD license. Several files are also under additional licenses; see the individual files for details.
Copyright (c) 1999-2005, Brian Wellington All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of the dnsjava project nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Thanks to Network Associates, Inc. for sponsoring some of the original dnsjava work in 1999-2000.
Thanks to Nominum, Inc. for sponsoring some work on dnsjava from 2000 to the present.