DnsContextFactory not accessible in java 17

[dominikrebhan]

Describe the bug
With Java 17 and Liberty trying to make a dns lookup fails. A ffdc is created with this message:

Exception = java.lang.IllegalAccessException
Source = com.ibm.ws.jndi.internal.WASURLObjectFactoryFinder
probeid = 81
Stack Dump = java.lang.IllegalAccessException: class com.ibm.ws.jndi.internal.WASURLObjectFactoryFinder cannot access class com.sun.jndi.url.dns.dnsURLContextFactory (in module jdk.naming.dns) because module jdk.naming.dns does not export com.sun.jndi.url.dns to unnamed module @188cf1f7

Steps to Reproduce

Properties env = new Properties();
env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.dns.DnsContextFactory");
env.put(Context.PROVIDER_URL, "dns:");
dirContext = new InitialDirContext(env);
 
Attributes attrs = dirContext.getAttributes("dns:/...");

Expected behavior
Successful dns lookup

Diagnostic information:

• OpenLiberty Version: 23.0.0.3
• Java Version: Java 17

Additional context
I think it is necessary to add this to the java9.options starting with java 17. This resolves my problem:

--add-exports
jdk.naming.dns/com.sun.jndi.url.dns=ALL-UNNAMED

https://github.com/OpenLiberty/open-liberty/blob/integration/dev/com.ibm.ws.kernel.boot/publish/platform/java/java9.options

[jhanders34]

#22360 was supposed to help this, but maybe the package name was wrong or it has changed.

[dominikrebhan]

Unfortunately this didn't help. I think it is because the namespace is different:

com.sun.jndi.dns vs. com.sun.jndi.url.dns

[gjwatts]

Sorry, I will start working on this.

[gjwatts]

Hi @dominikrebhan. To help with this recreate, can you please give me a specific example of an attribute name I can use in this line?
Attributes attrs = dirContext.getAttributes("dns:/...");

[dominikrebhan]

You can simply use any address. It won't go any further, it creates immediately the ffdc:

public void init(@Observes @Initialized(ApplicationScoped.class) Object init) {
    try {
        Properties env = new Properties();
        env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.dns.DnsContextFactory");
        env.put(Context.PROVIDER_URL, "dns:");
        var dirContext = new InitialDirContext(env);

        var attrs = dirContext.getAttributes("dns:/www.github.com");
        System.out.println(attrs);
    }
    catch (Exception ex) {
        ex.printStackTrace();
    }
}

I tried this with the vanilla zip from the download page on a fresh windows vm. I just had to copy the java9.options to my local server jvm.options, because it seems this isn't loaded either. But this may be another issue or just some local error. It happened on macOS as well, but I think the DNS-issue is more relevant.

messages.log
ffdc.log

[gjwatts]

@dominikrebhan Thanks for sending the messages.log file, that helped. I was getting the same DNS error and thought I was doing something wrong.
javax.naming.NameNotFoundException: DNS name not found [response code 3]; remaining name 'dns:/www.github.com'

However, I don't get the java.lang.IllegalAccessException exception in my log file, nor do I get an FFDC file created when I run it.

Looking at your messages.log file, I am guessing in your server.xml file for features you have something like:

    <featureManager>
        <feature>webProfile-10.0</feature>
        <feature>localConnector-1.0</feature>
    </featureManager>

In mine, I have:

    <featureManager>
        <feature>servlet-6.0</feature>
	<feature>localConnector-1.0</feature>
    </featureManager>

But when I switch to use the webProfile-10.0 feature (which pulls in the servlet-6.0 feature), then I get the same illegalAccessException that you do.

[gjwatts]

@dominikrebhan never mind, Jared figured out I was missing the jndi-1.0 feature that webProfile-10.0 pulls in. Once I include that in my server.xml

<featureManager>
	<feature>servlet-6.0</feature>
	<feature>jndi-1.0</feature>
        <feature>localConnector-1.0</feature>
    </featureManager>

Then I get the same illegalAccessException you reported. I am working on adding the correct entry into the java9.options file and adding a test for this into one of our FAT buckets.

Thank you for taking your time to report this to us so we can make Open Liberty even better!

[gjwatts]

@dominikrebhan I have merged the PR to get this fixed. I expect it to be in our next release. Thanks again for reporting it!