SimpleDS for Java 1.2 is released

[Nacho Coloma]

Hey guys,

SimpleDS is a Java persistence framework for GAE (think Objectify, but different). This release includes the following:

Serialize attributes as JSON

Something similar to what NDB introduced lately, you can choose between @Embedding a composite object or serializing it @AsJSON:

@Property @AsJSON
private AcmeObject myObject;

These fields get stored as Text attributes, which means that you cannot include them as query arguments (not that it would make any sense). We are using Jackson for JSON serialization/deserialization, so you can use anything in org.codehaus.jackson.annotate.

Predicates

Guava Predicates are now easier to use than ever:

@Override
public CursorList<Whatever> findByUser(Key userKey, boolean includeOldData, Cursor cursor) {
return entityManager.createQuery(Whatever.class)
.equal("userKey", userKey)
.withPredicate(includeOldData? null : new Predicate<Performance>() {
@Override
public boolean apply(Whatever input) {
return !input.isOld();
}
})
.withStartCursor(cursor)
.sortAsc("date")
.asCursorList(20);
}

This should save you some indexes in your datastore, and is a great way to implement filters based on a condition (such as the example above). As with anything else, setting the predicate to null is just a no-op.

Predicates are supported for any method that returns List, CursorList, CursorIterable and CursorIterator instances.

Demo app

This was an issue long overdue. We have put together a kickstart application at https://github.com/icoloma/simpleds-kickstart/

It is an introduction to put together SimpleDS, Jersey and AppEngine in a gradle project. You can play with the demo online at http://simpleds-kickstart.appspot.com/

Removed dependencies

We have reduced the list of dependency JARs required to deploy. JPA annotations are not supported anymore, and you do not need any Spring JARs anymore. The only two required dependencies that remain should be jackson for JSON serialization and slf4j for logging.

We have also moved from Google code to GitHub. All the wiki contents have been migrated to https://github.com/icoloma/simpleds/wiki/ - looks as hell, but we will eventually work on that.

Next in our roadmap: async operations and get partial entities (hopefully, with a shorter release cycle).

Merry Christmas to everyone!