Easy Java ORM for small projects

I'm current开发者_如何学Pythonly searching for a really easy way to get simple Java Objects persistent in Databases and/or XML and/or other types of data stores.

For big projects in the company i would use hibernate, ibatis, datanucleus or something like that. But with small private projects this will take over 80% of the worktime.

I also found "simpleORM" but this one requires to code data-related stuff pretty hardly into the data-model classes. I don't really like that style so this is no option for me.

Do you have a suggestion for some library which simply takes my objects and saves / loads them as they are or with very little configuration?

You could try my ORMLite library, which was designed as a simple replacement for hibernate and iBatis. I'm the main author. It supports a number of JDBC databases and has an Android backend. Here is the getting started section of the manual which has some code examples. Here also are working examples of simple usage patterns.

Try Norm. It's a lightweight layer over JDBC. It adds almost zero overhead to JDBC calls and is very easy to learn.

You could just serialize your objects into a file/database whatsoever.

If you want to define the mapping then you'd have to go for more configuration and the standard OR mappers out there (like Hibernate) don't really add that much on top.

You could try xstream. It's really simple OXM library working without upfront configuration.

Sample code:

XStream xstream = new XStream();
// marshalling
String xml = xstream.toXML(domainObject);
// unmarshalling
domainObject = xstream.fromXML(xml);

For relational database persistence try one of the JPA implementations, such as OpenJPA.

The setup overhead is minimal. You can let JPA to create your schema & tables for your from your object definitions, so you don't need to hand crank any sql. All you need to supply is some annotations on your entities and a single config file, persistence.xml.

You can also use jEasyORM (http://jeasyorm.sourceforge.net/). In most cases it automatically maps objects to database tables with no need for configuration.

You may want to consider www.sormula.org. Minimal programming/annotations and simple learning curve. It uses standard SQL and JDBC so will work with any relational db.

U could try SnakeORM http://sourceforge.net/p/selibs/wiki/Home/ It doesnt have many runtime dependencies, uses JPA annotations and follows DAO pattern.

Disclosure: I am the author of this project

Well if you want an ORM, then that implies that you want to map objects to tables, columns to fields etc. In this case, if you want to avoid the hassle of bigger ORM implementations, you could just use plain old JDBC, with simple DataAccessor patterns. But then this does not translated to XML directly.

If you want to just persist the object somewhere, and only care about "understanding" the object in Java, then serialization is a simple effective method, as Thomas mentioned earlier.

You could also try my little ORM library, Java2DB. I created it specifically for small projects that just want quick and easy access to their database. Check it out on GitHub.

Onyx Database is a very feature rich Java NoSQL database alternative. It's pure java with several persisting modes (caching, embedded-database, save-to-remote, and save-to-remote-cluster. It has an embedded ORM, and is probably the easiest persistence API I've used.