[CAMEL-8520] Camel XMPP doesn't use a DNS resolver to look at SRV records

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.15.0
• Fix Version/s: 2.15.1, 2.16.0
• Component/s: camel-xmpp
• Estimated Complexity: Unknown
• Assignee: Claus Ibsen
• Reporter: Ben Harris
• Created: 20/Mar/15 00:38
• Updated: 20/Mar/15 06:52
• Resolved: 20/Mar/15 06:52

Description

Camel XMPP doesn't use a DNS resolver to look at SRV records, whereas in 2.14.1 it did.

In 2.15.0, ConnectionConfiguration calls DNSUtil.resolveXMPPDomain(serviceName) which runs this code:

DNSUtil.java

public static List<HostAddress> resolveXMPPDomain(final String domain) {
        if (dnsResolver == null) {
            List<HostAddress> addresses = new ArrayList<HostAddress>(1);
            addresses.add(new HostAddress(domain, 5222));
            return addresses;
        }
        return resolveDomain(domain, 'c');
    }

dnsResolver is never initialised, so it returns the service name, in my case 'jabberzac.org', instead of the actual XMPP server from the SRV Record, 'xmpp.jabberzac.org', which then causes a timeout.

The dnsResolver is meant to be instantiated in init(), which is meant to be called by SmackConfiguration, but never is.

DNSUtil.java

    /**
     * Initializes DNSUtil. This method is automatically called by SmackConfiguration, you don't
     * have to call it manually.
     */
    public static void init() {
        final String[] RESOLVERS = new String[] { "javax.JavaxResolver", "minidns.MiniDnsResolver",
                        "dnsjava.DNSJavaResolver" };
        for (String resolver :RESOLVERS) {
            DNSResolver availableResolver = null;
            String resolverFull = "org.jivesoftware.smack.util.dns" + resolver;
            try {
                Class<?> resolverClass = Class.forName(resolverFull);
                Method getInstanceMethod = resolverClass.getMethod("getInstance");
                availableResolver = (DNSResolver) getInstanceMethod.invoke(null);
                if (availableResolver != null) {
                    setDNSResolver(availableResolver);
                    break;
                }
            }
            catch (ClassNotFoundException|NoSuchMethodException|SecurityException|IllegalAccessException|IllegalArgumentException|InvocationTargetException e) {
                LOGGER.log(Level.FINE, "Exception on init", e);
            }
        }
    }

2.14.1 doesn't seem to have this problem as DNSUtil class in 2.14.1 doesn't have an init() function which is meant to be 'automatically called', it just has a static code block:

    static {
        try {
            Hashtable env = new Hashtable();
            env.put("java.naming.factory.initial", "com.sun.jndi.dns.DnsContextFactory");
            context = new InitialDirContext(env);
        }
        catch (Exception e) {
            // Ignore.
        }
    }