Spring Commons Library

Commons library containing reusable patterns, extensions, properties, beans, and objects for Spring and Spring Boot

Compatibility

• Java 21
• Spring Boot 3

Setup

Add Dependency

Gradle

implementation("io.opengood.commons:spring-commons:VERSION")

Maven

<dependency>
    <groupId>io.opengood.commons</groupId>
    <artifactId>spring-commons</artifactId>
    <version>VERSION</version>
</dependency>

Note: See Release version badge above for latest version.

Features

Note: All examples are provided in Kotlin

Bean Refresher

EXPERIMENTAL

Sometimes one needs to dynamically refresh a Spring bean at runtime without restarting the application container. For example, a Spring bean may need to fetch updated data from a database and cache the results inside a bean.

The BeanRefresher component allows one to specify a bean name and its fully qualified class type to trigger a refresh of a bean without restarting the application container. On the next request for dependencies that use the bean, the updated instance will be injected.

To enable the BeanRefresher, add the following configuration to application.yml:

spring-commons:
  bean:
    refresh:
      enabled: true
      controller:
        enabled: true

Kotlin/Java API

One can use the BeanRefresher Kotlin/Java API to programmatically to refresh a bean:

val oldBean = applicationContext.getBean("greetingBean") as GreetingBean

beanRefresher.refresh(
    BeanRefreshConfig(
        beanName = "greetingBean",
        classType = GreetingBean::class.java,
    )
)

val newBean = applicationContext.getBean("greetingBean") as GreetingBean

newBean shouldNotBe oldBean

REST API

A REST controller endpoint is also provided to allow HTTP(S) refresh of Spring beans:

Request:

POST http://localhost:8080/spring-commons/bean/refresh
Accept: application/json
Content-Type: application/json

{"beanName":"greetingBean", "classType":"app.bean.GreetingBean"}

Response:

{"message":"Successfully refreshed bean 'greetingBean'"}

Recreation of Spring Beans

By default, BeanRefresher only reloads a Spring bean's definition. Sometimes, specific beans need to be recreated. To do so with BeanRefresher, add recreateBean = true to either the BeanRefresherConfig or to request JSON, for Kotlin/Java API and REST API, respectively.

Examples:

BeanRefreshConfig(
    beanName = "greetingBean",
    classType = GreetingBean::class.java,
    recreateBean = true,
)

POST http://localhost:8080/spring-commons/bean/refresh
Accept: application/json
Content-Type: application/json

{"beanName":"greetingBean", "classType":"app.bean.GreetingBean", "recreateBean": true}

---

WebClient Request and Response Loggers

By default, using WebClient does not provide logging of request and response information. Functions are provided to simplify this:

logRequest will log debug:

• Request
  • Method
  • URI
  • Headers

logResponse will log debug:

• Response
  • Status Code
  • Headers

Example:

import io.opengood.commons.spring.webclient.logRequest
import io.opengood.commons.spring.webclient.logResponse

@Configuration
class WebClientConfig {

    @Bean
    fun webClient(): WebClient {
        return WebClient.builder()
            .baseUrl("http://localhost:8080")
            .defaultHeader(
                HttpHeaders.CONTENT_TYPE,
                MediaType.APPLICATION_JSON_VALUE
            )
            .filters { exchangeFilterFunctions ->
                exchangeFilterFunctions.add(logRequest(log))
                exchangeFilterFunctions.add(logResponse(log))
            }
            .build()
    }

    companion object {
        @Suppress("JAVA_CLASS_ON_COMPANION")
        private val log = LoggerFactory.getLogger(javaClass.enclosingClass)
    }
}

---

Logging Web Client Builder

When one needs to log details of Spring WebClient requests and responses, one can configure the Netty HttpClient to wiretap and log request and response details at level DEBUG.

A loggingWebClientBuilder Spring bean is provided that is auto configured when the following configuration is added to application.yml:

spring-commons:
  web-client:
    logging:
      enabled: true

Then simply create a WebClient bean using the builder:

@Configuration
class TestWebClientConfig {

    fun webClient(
        @Qualifier("loggingWebClientBuilder") webClientBuilder: WebClient.Builder
    ) =
        webClientBuilder
            .baseUrl("http://localhost:8080")
            .defaultHeader(
                HttpHeaders.CONTENT_TYPE,
                MediaType.APPLICATION_JSON_VALUE
            )
            .build()
}

In order for Netty to write logs, its logger much be configured at level DEBUG in application.yml:

logging:
  level:
    reactor.netty.http.client.HttpClient: DEBUG

Any WebClient requests and responses used by the bean will be logged similar to as follows:

Request:

15:27:02.060 [qtp1001320766-66] DEBUG org.eclipse.jetty.server.HttpChannel MDC= - REQUEST for //localhost:11729/greeting?firstName=John on HttpChannelOverHttp@34998901{s=HttpChannelState@22052be6{s=IDLE rs=BLOCKING os=OPEN is=IDLE awp=false se=false i=true al=0},r=1,c=false/false,a=IDLE,uri=//localhost:11729/greeting?firstName=John,age=0}
GET //localhost:11729/greeting?firstName=John HTTP/1.1
User-Agent: ReactorNetty/1.0.14
Host: localhost:11729
Accept: */*
Content-Type: application/json

Response:

15:27:02.152 [reactor-http-nio-2] DEBUG i.o.c.s.w.LoggingWebClientConfig$$EnhancerBySpringCGLIB$$498409ee MDC= - [affd975a-1, L:/127.0.0.1:63371 - R:localhost/127.0.0.1:11729] READ: 252B HTTP/1.1 200 OK
Content-Type: application/json
Matched-Stub-Id: 62600bcd-4064-40a7-8547-bdc3af2577b5
Vary: Accept-Encoding, User-Agent
Transfer-Encoding: chunked
Server: Jetty(9.4.44.v20210927)

27
{"firstName":"John","lastName":"Smith"}
0

Note: This data should only be used for diagnostic purposes and should be disabled in production.

---

YAML Property Source Factory

Spring supports turning YAML configuration files into properties beans but only for application*.yml files. Custom YAML files are not supported. To enable this, use the YamlPropertySourceFactory on @ConfigurtionProperties bean classes:

Example:

import io.opengood.commons.spring.property.YamlPropertySourceFactory

@Configuration
@ConfigurationProperties(prefix = "app")
@ConstructorBinding
@PropertySource(
    value = ["classpath:app-properties.yml"],
    factory = YamlPropertySourceFactory::class
)
data class AppProperties(
    val properties: Map<String, String> = HashMap()
)

YAML file app-properties.yml:

app:
  properties:
    foo: bar
    baz: paz