Unlock 10 Powerful Spring Boot 3 Starters: Real‑World Cases & Code

Introduction

Developers often encounter performance bottlenecks and security issues in high‑concurrency scenarios. The Spring Boot ecosystem provides a rich set of open‑source starter components that address these pain points, allowing developers to focus on core business logic.

Practical Cases

2.1 ShedLock

ShedLock guarantees that a scheduled task runs only once across a cluster by acquiring a lock in external storage such as Mongo, JDBC, Redis, Hazelcast, or ZooKeeper.

Dependency coordinates

<dependency>
  <groupId>net.javacrumbs.shedlock</groupId>
  <artifactId>shedlock-spring</artifactId>
  <version>6.9.2</version>
</dependency>
<!-- Redis provider -->
<dependency>
  <groupId>net.javacrumbs.shedlock</groupId>
  <artifactId>shedlock-provider-redis-spring</artifactId>
  <version>6.9.2</version>
</dependency>

Basic usage

@Configuration
@EnableScheduling
@EnableSchedulerLock(defaultLockAtMostFor = "10m")
public class AppConfig {
    @Bean
    LockProvider redisLockProvider(RedisConnectionFactory factory) {
        return new RedisLockProvider(factory);
    }

    @Scheduled(...)
    @SchedulerLock(name = "scheduledTaskName")
    public void scheduledTask() {
        // TODO
    }
}

Official repository: https://github.com/lukas-krecan/ShedLock

2.2 p6spy

p6spy intercepts and logs all JDBC statements without modifying existing code, providing a convenient way to monitor database interactions.

Dependency coordinates

<dependency>
  <groupId>com.github.gavlyukovskiy</groupId>
  <artifactId>p6spy-spring-boot-starter</artifactId>
  <version>1.11.0</version>
</dependency>

Configuration (application.yml)

decorator:
  datasource:
    p6spy:
      enable-logging: true
      logging: slf4j

Sample log output (image):

Official repository: https://github.com/gavlyukovskiy/spring-boot-data-source-decorator

2.3 Logbook

Logbook is an extensible Java library that logs HTTP requests and responses, making it easy to persist and analyze traffic for auditing or debugging.

Dependency coordinates

<dependency>
  <groupId>org.zalando</groupId>
  <artifactId>logbook-spring-boot-starter</artifactId>
  <version>3.12.2</version>
</dependency>

Configuration (application.yml)

logging:
  level:
    '[org.zalando.logbook.Logbook]': TRACE

Custom bean example:

@Bean
public Logbook logbook() {
    return Logbook.builder()
        .condition(Conditions.exclude(
            Conditions.requestTo("/api/query"),
            Conditions.contentType("application/octet-stream"),
            Conditions.header("X-Secret", "true")))
        .sink(new DefaultSink(new DefaultHttpLogFormatter(), new DefaultHttpLogWriter()))
        .build();
}

Official repository: https://github.com/zalando/logbook

2.4 Jasypt

Jasypt Spring Boot adds encryption support for Spring Boot property sources, allowing sensitive configuration values to be stored securely.

Dependency coordinates

<dependency>
  <groupId>com.github.ulisesbocchio</groupId>
  <artifactId>jasypt-spring-boot-starter</artifactId>
  <version>3.0.5</version>
</dependency>

Basic usage

// Encrypt a value
java org.jasypt.intf.cli.JasyptPBEStringEncryptionCLI \
  input="xxxooo" password="aaaabbbbcccc6666" algorithm="PBEWithMD5AndDES"

Encrypted value can be used in application.yml:

spring:
  datasource:
    password: ENC(x8hoXK78YcyblFzV3vohDA==)

Run the application with the encryption password:

java -jar app.jar --jasypt.encryptor.password=aaaabbbbcccc6666

Official repository: https://github.com/ulisesbocchio/jasypt-spring-boot

2.5 Bucket4j

Bucket4j implements the token‑bucket algorithm for rate limiting, supporting both in‑memory and distributed caches via JCache.

Dependency coordinates

<dependency>
  <groupId>com.giffing.bucket4j.spring.boot.starter</groupId>
  <artifactId>bucket4j-spring-boot-starter</artifactId>
  <version>0.12.10</version>
</dependency>
<dependency>
  <groupId>com.bucket4j</groupId>
  <artifactId>bucket4j-redis</artifactId>
  <version>8.10.1</version>
</dependency>

Configuration (application.yml)

bucket4j:
  cache-to-use: redis-lettuce
  filters:
    - filter-method: webflux
      cache-name: product-cache
      id: product_filter
      url: /products/.*
      rate-limits:
        - cache-key: getParameter("id")
          bandwidths:
            - capacity: 2
              time: 30
              unit: seconds
              refill-speed: interval

Example Redis client bean:

@Bean
RedisClient redisClient() {
    RedisURI redisURI = RedisURI.create("localhost", 6379);
    redisURI.setDatabase(6);
    redisURI.setCredentialsProvider(new RedisCredentialsProvider() {
        @Override
        public Mono<RedisCredentials> resolveCredentials() {
            return Mono.just(RedisCredentials.just(null, "123123"));
        }
    });
    return RedisClient.create(redisURI);
}

Sample request result (image):

2.6 gRPC

grpc‑spring‑boot‑starter integrates Google’s high‑performance RPC framework with Spring Boot, simplifying server and client setup.

Dependency coordinates

<dependency>
  <groupId>net.devh</groupId>
  <artifactId>grpc-spring-boot-starter</artifactId>
  <version>3.1.0.RELEASE</version>
</dependency>

Configuration (application.yml)

grpc:
  client:
    GLOBAL:
      address: localhost:7777
      negotiation-type: plaintext
  server:
    port: 7777

Official documentation: https://grpc-ecosystem.github.io/grpc-spring/zh-CN/

2.7 Retrofit

retrofit‑spring‑boot‑starter provides a type‑safe HTTP client for Java and Android, enabling quick integration of REST services.

Dependency coordinates

<dependency>
  <groupId>com.github.lianjiatech</groupId>
  <artifactId>retrofit-spring-boot-starter</artifactId>
  <version>3.1.7</version>
</dependency>

Define an interface

@RetrofitClient(baseUrl = "${test.baseUrl}")
public interface UserService {
    /** Get user name by id */
    @POST("getName")
    String getName(@Query("id") Long id);
}

Inject and use:

@Service
public class BusinessService {
    private final UserService userService;
    public BusinessService(UserService userService) {
        this.userService = userService;
    }
    public void doBusiness() {
        // call userService
    }
}

Official repository: https://github.com/LianjiaTech/retrofit-spring-boot-starter

2.8 MapStruct‑Plus

MapStruct‑Plus extends MapStruct with additional features, automatically generating conversion code between Java types.

Dependency coordinates

<dependency>
  <groupId>io.github.linpeilie</groupId>
  <artifactId>mapstruct-plus-spring-boot-starter</artifactId>
  <version>1.4.8</version>
  <scope>runtime</scope>
</dependency>

Basic usage

@AutoMapper(target = UserDto.class)
public class User {
    private String name;
    private Integer age;
}
public class UserDto {
    private String name;
    private Integer age;
}

Generated mapper can be used in tests:

@Resource
private Converter converter;
@Test
public void test() {
    User user = new User();
    user.setName("jack");
    user.setAge(23);
    UserDto userDto = converter.convert(user, UserDto.class);
    System.out.println(userDto);
}

Official repository: https://github.com/linpeilie/mapstruct-plus

2.9 Redisson

Redisson provides a Java client for Redis/Valkey with distributed data structures and utilities, including distributed locks.

Dependency coordinates

<dependency>
  <groupId>org.redisson</groupId>
  <artifactId>redisson-spring-boot-starter</artifactId>
  <version>3.50.0</version>
</dependency>

Distributed lock example

RLock lock = redisson.getLock("myLock");
// Simple lock
lock.lock();
// Auto‑unlock after 10 seconds
lock.lock(10, TimeUnit.SECONDS);
// Try lock with wait time and lease time
boolean acquired = lock.tryLock(100, 10, TimeUnit.SECONDS);
if (acquired) {
    try {
        // critical section
    } finally {
        lock.unlock();
    }
}

Official repository: https://github.com/redisson/redisson?tab=readme-ov-file

2.10 Resilience4j

Resilience4j is a lightweight fault‑tolerance library designed for functional programming, offering circuit breakers, rate limiters, retries, and bulkheads.

Dependency coordinates

<dependency>
  <groupId>io.github.resilience4j</groupId>
  <artifactId>resilience4j-spring-boot3</artifactId>
  <version>2.3.0</version>
</dependency>

Configuration (application.yml)

resilience4j:
  circuitbreaker:
    configs:
      userCfg:
        minimum-number-of-calls: 2
        wait-duration-in-open-state: 10s
    instances:
      userList:
        base-config: userCfg

Business code example

private final CircuitBreakerRegistry circuitBreakerRegistry;
public UserService(CircuitBreakerRegistry circuitBreakerRegistry) {
    this.circuitBreakerRegistry = circuitBreakerRegistry;
}
@CircuitBreaker(name = "userList", fallbackMethod = "findAllFallback")
public List<User> findAll() {
    System.out.println(1 / 0); // trigger exception
    try { TimeUnit.MILLISECONDS.sleep(2000); } catch (InterruptedException e) {}
    return List.of(
        new User(1L, "Pack", 20),
        new User(2L, "Jack", 22),
        new User(3L, "Wake", 24),
        new User(4L, "Caoo", 26)
    );
}
public List<User> findAllFallback(Throwable ex) {
    System.err.printf("Exception: %s%n", ex.getMessage());
    return List.of();
}

Official documentation: https://resilience4j.readme.io/docs/getting-started