README.md

MongoDB distributed lock

A distributed-lock-mongodb-spring-boot-starter repository project contains custom written Distributed Lock starter based on Spring Boot and MongoTemplate with Testcontainers integration testing and fabric8 docker-maven-plugin maven module to help run example showcase application uses mongo docker container

Versions convention

We support next version convention:

Distributed Lock version	Spring Boot version	GitHub branch
3.0.6	3.0.6	master
2.7.11	2.7.11	spring-boot-2.7.x
2.6.14-4	2.6.14	spring-boot-2.6.x
2.5.14-4	2.5.14	spring-boot-2.5.x
2.4.13-4	2.4.13	spring-boot-2.4.x
2.3.12-4	2.3.12.RELEASE	spring-boot-2.3.x
2.2.13-4	2.2.13.RELEASE	spring-boot-2.2.x
2.1.18-4	2.1.18.RELEASE	spring-boot-2.1.x

Installation

<dependency>
    <groupId>io.github.daggerok</groupId>
    <artifactId>distributed-lock-mongodb-spring-boot-starter</artifactId>
    <version>RELEASE</version>
</dependency>

Or:

<dependency>
    <groupId>io.github.daggerok</groupId>
    <artifactId>distributed-lock-mongodb-spring-boot-starter</artifactId>
    <version>LATEST</version>
</dependency>

...if you need SNAPSHOT

Supported operations

• Acquire lock (try lock)
• Release lock (try to unlock)
• Acquire lock and consume (only if lock was acquired)
• Acquire lock and supply value (only if lock was acquired)

Usage

Inject distributed lock

A DistributedLockAutoConfiguration will provide DistributedLock you can use as locking implementation.

Feel free to simply inject it by defined single constructor in your spring Bean:

@Service
public class MyService {

    @Autowired
    private MyService myService;

    // skipped...
}

Or you can inject it using @Auqtowired annotation by field injection (not recommended):

@Service
public class MyService {

    private final MyService myService;

    public MyService(MyService myService) {
        this.myService = myService;
    }

    // skipped...
}

Or query it from ApplicationContext directly:

@SpringBootApplication
public class MyApplication {
    public static void main(String[] args) {
        var context = SpringApplication.run(ExampleApplication.class, args);
        var distributedLock = context.getBean(DistributedLock.class);
        // skipped...
    }
}

acquire(Lock config)

Acquire lock (try lock)

Optional<Lock> maybeLock = distributedLock.acquire(Lock.of(identifier));
if (maybeLock.isPresent()) log.debug("Lock was acquired.");
else log.warn("Lock can't be acquired...");

release(String lockId)

Release lock (try to unlock)

Optional<Lock> maybeUnlock = distributedLock.release("642b52e873d0ec7cd4463f05")
if (maybeUnlock.isPresent()) log.debug("Lock was released.");
else log.warn("Can't release lock...");

acquireAndRun

Acquire lock and consume (only if lock was acquired)

Optional<Boolean> maybeSync = distributedLock.acquireAndGet(Lock.of("sync"), () -> leaderElection.sync());
if (maybeSync.isPresent()) log.debug("Data synchronization was completed")
else log.warn("Data wasn't synced");

acquireAndGet

Acquire lock and supply value (only if lock was acquired)

Optional<SyncResult> syncResult = distributedLock.acquireAndGet(Lock.of("ETL"), () -> syncService.etl());
maybeResult.ifPresent(result -> log.debug("Synchronization complete with: {}", result));