ShieldDB

ShieldDB is a simple embedded database with JSON file backend with optional in-memory read cache.

Features

• Easy to use : use ShieldDB like you use a standard Java List
• Easy to extends
• No mandatory external dependencies
• No reflection API usage (except for some json mapper implementation like Gson)

Contributing to ShielDB

If you want to contribute to ShieldDB or if you want better know how ShieldDB is working, you can check the DEVELOPER.md.

How to use it?

Add the core dependency

...
<dependencies>
	...
	<dependency>
		<groupId>nf.fr.k49</groupId>
		<artifactId>shielddb-core</artifactId>
		<version>0.1.1</version>
	</dependency>
	...
</dependencies>
...

Add as dependency a mapper

...
<dependencies>
	...
	<dependency>
		<groupId>nf.fr.k49</groupId>
		<artifactId>shielddb-gson-backend</artifactId>
		<version>0.1.1</version>
	</dependency>
	...
</dependencies>
...

Note: At this time, there is only a Gson mapper implementation. But you can make yours and maybe make a Pull Request :-)

Initialize a ShieldDB instance

Create a bean class:

public class User {
	private String firstname;
	private String lastname;
	private int age;
	private LocalDate birthDate;
	...
}

final List<User> userDb = ShieldDB.<User>builder()
		.mapper(new ShieldDBGson<User>())
		.storage(new FileStorage("User.json"))
		.build();

Note: If you want to store a type that has no custom equals implementation, you may have some issues.

(Optional) Add some shield to customize the way ShieldDB will read/write

final List<User> userDb = ShieldDB.<User>builder()
		.shield(new AtomicShield())// ensure only one thread use userDb
		.shield(new ReadOnlyShield())// throw an UnsupportedOperationException on write access
		//.shield(new SilentReadOnlyShield())// do nothing on write access (no exception)
		.shield(new InMemoryArrayListReadCacheShield())// add an in memory read cache
		.mapper(new ShieldDBGson<User>())
		.storage(new FileStorage("User.json"))
		.build();

See more usage example here: https://github.com/kuroidoruido/ShieldDB/tree/master/shielddb-demo-app/

Release process

• ensure snapshot deploys: mvn clean deploy
• set all packages to a release version: mvn versions:set -DnewVersion=1.0.0
• commit changes
• deploy release: mvn clean deploy
• await new release is visible on maven central: https://repo1.maven.org/maven2/nf/fr/k49/
• set all packages to the next snapshot version: mvn versions:set -DnewVersion=1.0.1-SNAPSHOT
• commit changes