Using loadjava utility to load a 3rd party jar file

Question

Hi Folks,
    I need to validate if a java class, stored into an Oracle Database, is able to connect to a SQLite database.
    In order to connect to SQLite I'm using the the jar file sqlite-jdbc-3.7.2.jar that I got from  https://bitbucket.org/xerial/sqlite-jdbc/downloads
    Then I tried to load the jar file into Oracle Database using the command:
    loadjava -resolve -user system/xpto@tm014_23 -schema novacap sqlite-jdbc-3.7.2.jar
    The result is a series of error messages with the error code ORA-29533.
    Ex: - Attempt to overwrite class or resource org/sqlite/Codes while defining or compiling SYSTEM.org/sqlite/Codes
    Can you guys help me?
Thanks,
Luis

Answer 1

I need to validate if a java class, stored into an Oracle Database, is able to connect to a SQLite database.
You need to explain that a little more.
How could a java class within Oracle connect to a SQLLite database if the driver it needs isn't already loaded into Oracle.
The fact that you have to load the driver jar file tells you that the class will not be able to connect to SQLLite.
The recommended way to develop with 'Java in the database' is to first write and test the code OUTSIDE the database. Then when it works load it in the databse.
So use a copy of the Java class and test it outside the database to see if it can connect.
Also since 11g you could just load that jar as a 'database resident' jar file. If you don't do that then Oracle just extracts all of the files in the jar and tries to load them one at a time. So using 'resolve' won't work because Oracle isn't going to load the classes in the proper order.
See 'database resident jars' in the Java Dev Guide
http://docs.oracle.com/cd/B28359_01/java.111/b31225/chtwo.htm#BEJCBAHI
Database Resident JARs
Starting with 11g release 1 (11.1), when you load the contents of a JAR into the database, you have the option of creating a database object representing the JAR itself. In this way, you can retain an association between this JAR object and the class, resource, and source objects loaded from the JAR. This enables you to:
  Use signed JARs and JAR namespace segregation in the same way as you use them in standard JVM.
  Manage the classes that you have derived from a JAR while loading it into the database as a single unit. This helps you to prevent individual redefinition of the classes loaded from the JAR. It also enables you to drop the whole set of classes loaded from the JAR, irrespective of the contents or the continued existence of the JAR on the external file system, at the time of dropping it.
In order to load a JAR into the database, you have the following options of the loadjava tool:
  -jarsasdbobjects
  -prependjarnames
For more information regarding the loadjava tool options, refer to "The loadjava Tool" section.