JetBrains Xodus is a transactional schema-less embedded database that is written in Java and Kotlin. It was initially developed for JetBrains YouTrack, an issue tracking and project management tool. Xodus is also used in JetBrains Hub, the user management platform for JetBrains' team tools, and in some internal JetBrains projects.
- Xodus is transactional and fully ACID-compliant.
- Xodus is highly concurrent. Reads are completely non-blocking due to MVCC and true snapshot isolation.
- Xodus is schema-less and agile. It does not require schema migrations or refactorings.
- Xodus is embedded. It does not require installation or administration.
- Xodus is written in pure Java and Kotlin.
- Xodus is free and licensed under Apache 2.0.
Hello Worlds!
To start using Xodus, define dependencies:
<!-- in Maven project -->
<dependency>
<groupId>org.jetbrains.xodus</groupId>
<artifactId>xodus-openAPI</artifactId>
<version>2.0.1</version>
</dependency>// in Gradle project
dependencies {
compile 'org.jetbrains.xodus:xodus-openAPI:2.0.1'
}Read more about managing dependencies.
There are three different ways to deal with data, which results in three different API layers: Environments, Entity Stores and Virtual File Systems.
Environments
Add dependency on org.jetbrains.xodus:xodus-environment:2.0.1.
try (Environment env = Environments.newInstance("/home/me/.myAppData")) {
env.executeInTransaction(txn -> {
final Store store = env.openStore("Messages", StoreConfig.WITHOUT_DUPLICATES, txn);
store.put(txn, StringBinding.stringToEntry("Hello"), StringBinding.stringToEntry("World!"));
});
}Entity Stores
Add dependency on org.jetbrains.xodus:xodus-entity-store:2.0.1, org.jetbrains.xodus:xodus-environment:2.0.1 and org.jetbrains.xodus:xodus-vfs:2.0.1.
try (PersistentEntityStore entityStore = PersistentEntityStores.newInstance("/home/me/.myAppData")) {
entityStore.executeInTransaction(txn -> {
final Entity message = txn.newEntity("Message");
message.setProperty("hello", "World!");
});
}Virtual File Systems
Add dependency on org.jetbrains.xodus:xodus-vfs:2.0.1 and org.jetbrains.xodus:xodus-environment:2.0.1.
try (Environment env = Environments.newInstance("/home/me/.myAppData")) {
final VirtualFileSystem vfs = new VirtualFileSystem(env);
env.executeInTransaction(txn -> {
final File file = vfs.createFile(txn, "Messages");
try (DataOutputStream output = new DataOutputStream(vfs.writeFile(txn, file))) {
output.writeUTF("Hello ");
output.writeUTF("World!");
} catch (IOException e) {
throw new ExodusException(e);
}
});
vfs.shutdown();
}Building from Source
Gradle is used to build, test, and publish. JDK 1.8 or higher is required. To build the project, run:
./gradlew build
To assemble JARs and skip running tests, run:
./gradlew assemble
