Ammentos is a lightweight persistence framework for JDK 5. It does not require any installation nor configuration; just put a jar file into your classpath and start writing code. It is designed so that your persistence code will be dramatically short and so that you won't have to spend a lot of time to learn how to use it. It is about 72Kb large and it does not require any external library except for your database JDBC driver. You can use it in desktop applications or in server-based environments.
The Apache ODF Toolkit is a set of Java modules that allow programmatic creation, scanning, and manipulation of Open Document Format (ISO/IEC 26300 == ODF) documents. Unlike other approaches that rely on runtime manipulation of heavy-weight editors via an automation interface, the ODF Toolkit is lightweight and ideal for server use.
DataNucleus AccessPlatform is a standards-compliant Java persistence product. It is fully compliant with the JDO1, JDO2, JDO2.1, JDO2.2, JDO3, JPA1, and JPA2 Java standards, and provides a REST API. It complies with the OGC Simple Feature Spec for persistence of geospatial Java types. It allows access to all popular RDBMS available today, together with the MongoDB, LDAP, NeoDatis, JSON, Excel/ODF spreadsheets, XML, BigTable, HBase, and Neo4j databases.
The Geomajas API project contains some annotations that can be used to indicate which parts (which classes and which (public) methods or fields) are considered as the API. This is particularly useful for projects where you want to mark the API without the need to refactor everything to interfaces and factories.
JRel is a library for the Java language that can be used to construct database queries in a programmatic fashion using a subset of the relational algebra. These queries are expressions in the form of 100% native Java code, and are translated at runtime into compliant ANSI-SQL usable with a variety of SQL databases.