TL DR; Want some Java help with connecting to a truly local database ( no access to server tech ), or if you can whip up code, that will work. All it has to do is query the DB ( MS Access, although can be changed ), and output a JSON string. See EDIT2 for more specificity.
EDIT: Before anyone says JDBC; I looked through the tutorials ( started reading in depth ), but most of it seems to be geared towards server tech, which I have no access to.
EDIT2: Seems most the answers so far are requiring an installation of some kind which I unfortunately cannot do ( and failed to mention, so I apologize ). However, this is what is currently being used and I would like a solution similar for Java that would make it more cross-browser compatible as opposed to being HTA only (link: https://launchpad.net/accessdb )
Okay, for the long version. I’m trying to make use of a local database to create a desktop style application for work ( and possibly make use of the knowledge for other projects ). The database I can create without a problem ( MS Access 2003, just happens to be quickly available ). Currently I’m using ActiveX scripting to work with the database in a HTML Application (*.HTA file works only with Internet Explorer), I would really like to make this more cross browser ( in the event the company EVER switches to an actual browser ) by using JAVA to access the database, then output the results in JSON to a local variable JavaScript can call and make use of.
Honestly would rather tutorial type information as I want to actually learn why this works so I can later modify it to suit my needs. I have Eclipse installed as well as JDK, and can right small programs in Java, so not completely brain dead ( but not far from 😛 ). I’ve been working with JavaScript so I can read quite a bit of Java code as it stands ( not the same syntax since they are not related, but the little I do know of Java I can translate back to JS without problem ).
Anyway, any assistance would be greatly appreciated. I can continue developing with ActiveX ( as I know that works on the system and I’m 99% sure they will continue using Internet Explorer, but, would like some flexibility ).
I am not sure I understood your requirements very well, however I did decipher some key points. What I am suggesting will let you deliver a complete working application in a single package (say a JAR) that will not require much (if any) configuration or administration of servers.
Some Required skills:
Datastore
JDBC can be used with any database that has a JDBC driver, which isn’t necessarily a database in “network mode”, it can be used with embedded databases as well.
Here is an example with Derby in embedded mode:

Here are some 100% Java and embeddable databases:
http://www.h2database.com/html/main.html
http://db.apache.org/derby/
http://hsqldb.org/
Web tier
You can also embed a Web server like Jetty.
Embedding Jetty.
Please note that there are other web servers that you can use this way.