Switch to Spring Boot String to Duration conversion.

docs/src/main/asciidoc/spring-cloud-commons.adoc

@@ -809,7 +809,7 @@ implementation.
 To make use of it, you need to have `com.github.ben-manes.caffeine:caffeine` in the classpath.
 The default setup includes `expireAfterWrite` set to 30 seconds and records set to soft references.
 
-You can set your own `TTL` value (the time after write after which entries should be expired), expressed as `Duration`, by passing a `String` compliant with the https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/time/Duration.html#parse(java.lang.CharSequence)[`Duration` API]
+You can set your own `TTL` value (the time after write after which entries should be expired), expressed as `Duration`, by passing a `String` compliant with the https://docs.spring.io/spring-boot/docs/current/reference/html/spring-boot-features.html#boot-features-external-config-conversion-duration[Spring Boot `String` to `Duration` converter syntax].
 as the value of `spring.cloud.loadbalancer.cache.ttl` property.
 
 You can also override the default Caffeine Cache setup for the LoadBalancer by passing your own https://static.javadoc.io/com.github.ben-manes.caffeine/caffeine/2.2.2/com/github/benmanes/caffeine/cache/CaffeineSpec.html[Caffeine Specification]

spring-cloud-loadbalancer/src/main/java/org/springframework/cloud/loadbalancer/cache/CaffeineBasedLoadBalancerCacheManager.java

@@ -24,8 +24,8 @@ import org.springframework.util.StringUtils;
 import static org.springframework.cloud.loadbalancer.core.CachingServiceInstanceListSupplier.SERVICE_INSTANCE_CACHE_NAME;
 
 /**
- * A Spring Cloud LoadBalancer specific implementation of {@link CaffeineCacheManager} that
- * implements the {@link LoadBalancerCacheManager} marker interface.
+ * A Spring Cloud LoadBalancer specific implementation of {@link CaffeineCacheManager}
+ * that implements the {@link LoadBalancerCacheManager} marker interface.
  *
  * @author Olga Maciaszek-Sharma
  * @since 2.2.0

spring-cloud-loadbalancer/src/main/java/org/springframework/cloud/loadbalancer/cache/LoadBalancerCacheProperties.java

@@ -34,8 +34,10 @@ public class LoadBalancerCacheProperties {
 	/**
 	 * Time To Live - time counted from writing of the record, after which cache entries
 	 * are expired, expressed as a {@link Duration}. The property {@link String} has to be
-	 * in keeping with the appropriate syntax as specified in
-	 * {@link Duration#parse(CharSequence)}.
+	 * in keeping with the appropriate syntax as specified in Spring Boot
+	 * <code>StringToDurationConverter</code>.
+	 * @see <a href=
+	 * "https://github.com/spring-projects/spring-boot/blob/master/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/convert/StringToDurationConverter.java">StringToDurationConverter.java</a>
 	 */
 	private Duration ttl = Duration.ofSeconds(30);
 
@@ -51,14 +53,13 @@ public class LoadBalancerCacheProperties {
 		return ttl;
 	}
 
-	public void setTtl(String ttl) {
-		this.ttl = Duration.parse(ttl);
+	public void setTtl(Duration ttl) {
+		this.ttl = ttl;
 	}
 
 	/**
-	 * Caffeine-specific LoadBalancer cache properties.
-	 * NOTE: Passing your own Caffeine specification will override any other LoadBalancerCache settings,
-	 * including TTL.
+	 * Caffeine-specific LoadBalancer cache properties. NOTE: Passing your own Caffeine
+	 * specification will override any other LoadBalancerCache settings, including TTL.
 	 */
 	public static class Caffeine {