CrossDB  
   An open source Java API for writing object oriented SQL statements that will run on any database. [Open source]
   http://www.crossdb.com/

FireStorm  
   Generates database persistence logic based on relational database schema. Generates DAO, EJB and JDBC code.
   http://www.codefutures.com/firestorm/

The Apache DB Project  
   Project charged with the creation and maintenance of commercial-quality, open-source, database solutions. Mailing list signup, guidelines, repositories, and proposals.
   http://db.apache.org/

Java Client Database (JCDatabase)  
   A simplified version of JDBC that runs on both the server and as part of client applications. [Commercial]
   http://www.digitalscores.com/jcdatabase/

Java Database Tools, Products and Resources  
   Extensive list of utilities for OO, OR and relational database application development in Java.
   http://www.javaskyline.com/database.html

JSQL Product Suite  
   Classes for RDBMS server support, such as connection pooling, authentication, and caching. [Commercial]
   http://www.cariboulake.com/jetspeed/portal/user/anon/page/default.psml/js_pane/SoftwareProducts/DisplayContentJSP?contentDir=software&contentVal=jsql.jsp

Eclipse Database  
   An advanced data modeling Eclipse plugin which allows: Data modeling, reverse/forward, generate DDL to SQL files, dictionary validation, working with 23 RDBMS (MySQL, DB2, Oracle), database console, working at three levels (diagrams, wizard, XML or Veloc
   http://www.eclipsedatabase.com/

PoolMan  
   Offers configurable JDBC pools to multiple databases and SQL query/ResultSet cache. Generic Java object pooling is also available. [LGPL]
   http://sourceforge.net/projects/poolman