Apache Common dbutils

DbUtils is a small set of classes designed to make working with JDBC easier.

Apache OpenJPA

Apache OpenJPA is a Java persistence project at The Apache Software Foundation that can be used as a stand-alone POJO persistence layer or integrated into any Java EE compliant container and many other lightweight frameworks, such as Tomcat and Spring.

Platform： ；License：Apache License Version 2.0
Reference：https://openjpa.apache.org/

Ebean ORM

Ebean is an open source (LGPL license) Java Object Relational Mapping tool. It uses JPA Annotations (@entity, @OneToMany, etc) for mapping. It provides a simple API for fetching and saving object graphs.

Persist

Persist is a no-nonsense Java-based ORM/DAO tool. It provides only the minimal amount of functionalities necessary to map objects or maps from database queries and to statement parameters.

BeanKeeper

BeanKeeper is an O/R (object/relation) mapping library. Its task is to map java objects to a relational database, and to offer a powerful query service to retrieve them.

ODAL

Objective database abstraction layer (ODAL) is a high-performance database manipulation framework. Features include query API, O-R mapping, data validation/conversion, stored procedure support, code generation. Minimal dependencies. Short startup time.

Velosurf

Velosurf provides an 'out-of-the-box' automatized mapping of database tables and fields, along with the ability to easily define custom entities, queries and actions in SQL. It is a lightweight placeholder to persistence systems.

Ammentos

Ammentos is a lightweight persistence framework for Java, probably the very first one in the world available using JDK5 annotations. By far it is one of the most simple to use: no installation required, no configuration, no external dependencies. Ammentos is clean: no accessor methods required breaking good encapsulation, no interfaces to implement or base classes to extend dirtying your design. Ammentos is plug and play: just put a single jar in your classpath and start persisting your model. Ammentos is a standalone libray: you can embed it indifferently in desktop applications, web applications etc.

JDBCPersistence

JDBCPersistence is an Object Relational Mapping Framework. Designed for use in high volume online banking application the package delivers performance matching of that exhibited by hand written JDBC code. The differentiating features of JDBCPersistence are a result of the focus placed first and foremost on performance followed by making programmer most effective by building on existing knowledge of SQL, JDBC APIs, IDEs and, at the same time, avoiding creation of dependencies on specific libraries, tools, IDEs.

DataNucleus AccessPlatform

The DataNucleus AccessPlatform provides persistence and retrieval of data to a range of datastores using a range of APIs, with a range of query languages.

Prevayler

Prevayler provides transparent ACID persistence and replication for plain old Java objects. It is literally several thousand times faster than using a relational database through JDBC.

Hibernate

Hibernate is a powerful, ultra-high performance object/relational persistence and query service for Java. Hibernate lets you develop persistent objects following common Java idiom - including association, inheritance, polymorphism, composition and the Java collections framework. Extremely fine-grained, richly typed object models are possible. The Hibernate Query Language, designed as a ""minimal"" object-oriented extension to SQL, provides an elegant bridge between the object and relational worlds. Hibernate is now the most popular ORM solution for Java.

Ozone

The Ozone Database Project is a open initiative for the creation of an open source, Java based, object-oriented database management system. Ozone includes a fully W3C compliant DOM implementation that allows you to store XML data. You can use any XML tool to provide and access these data. Support classes for Apache Xerces-J and Xalan-J are included.

JODB

JODB (Java Objects Database) is the open source object-oriented database somewhat similar to db4objects but entirely oriented for Java community and completely free for personal and commercial use. Performance, size and scalability are the cornerstones of this project. The database use soft reference based caches to effectively use available RAM and in the same time minimize footprint when memory is pricey. The queries are optimized to the minimal possible objects instantiations during the search so that garbage collector will have more time to 'rest' which is especially important for busy server applications (GC is still expensive and its unlikely to change in near future).The ultimate goal for this project is to reach enterprise level visibility and compete with folks like MySql or Oracle.

Perst

Perst is McObject's open source, dual license, object-oriented embedded database system (ODBMS). It is available in one edition developed as an all-Java embedded database, and another implemented in C# (for Microsoft .NET Framework applications). Perst gives developers the ability to sort, store and retrieve objects in their applications with maximum speed and with low memory and storage overhead, while leveraging the object-oriented paradigm of Java and C#.

MyOODB

MyOODB (My Object-Oriented Database) is an integrated database and Web environment that provides true distributed objects, implicit/explicit multi-concurrent nested transactions, seamless Web tunneling, and database self-healing. MyOODB is one part of a two part SDK solution. Together with MyOOWEB, MyOOSDK provides a development environment for people who desire small, fast, but powerful applications.

SmallSQL

SmallSQL is a 100% pure Java DBMS, a relational database for Java desktop applications. It has a JDBC 3.0 interface and offering many ANSI SQL 92 and ANSI SQL 99 features. It is very small and fast because it does not have a network interface.

db4o

db4o is the open source object database that enables Java and .NET developers to store and retrieve any application object with only one line of code, eliminating the need to predefine or maintain a separate, rigid data model.

Hibernate Spatial

Hibernate Spatial is a generic extension to Hibernate for handling geographic data. Hibernate Spatial is open source and licensed under the LGPL license. Hibernate Spatial allows you to deal with geographic data in a standardized way. It abstracts away from the specific way your database supports geographic data, and provides a standardized, cross-database interface to geographic data storage and query functions.

License：LGPL

Apache Derby

Apache Derby, an Apache DB subproject, is an open source relational database implemented entirely in Java and available under the Apache License, Version 2.0. Some key advantages include:

• Derby has a small footprint -- about 2.6 megabytes for the base engine and embedded JDBC driver.
• Derby is based on the Java, JDBC, and SQL standards.
• Derby provides an embedded JDBC driver that lets you embed Derby in any Java-based solution.
• Derby also supports the more familiar client/server mode with the Derby Network Client JDBC driver and Derby Network Server.
• Derby is easy to install, deploy, and use.