Add CaffeineCacheManager class conditions to LoadBalancerCacheAutoConfiguration. (#891)

spring-cloud-loadbalancer/src/main/java/org/springframework/cloud/loadbalancer/config/LoadBalancerCacheAutoConfiguration.java

@@ -25,12 +25,14 @@ import org.apache.commons.logging.LogFactory;
 
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.AnyNestedCondition;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.cache.CacheManager;
+import org.springframework.cache.caffeine.CaffeineCacheManager;
 import org.springframework.cache.interceptor.CacheAspectSupport;
 import org.springframework.cloud.client.loadbalancer.reactive.OnNoRibbonDefaultCondition;
 import org.springframework.cloud.loadbalancer.cache.CaffeineBasedLoadBalancerCacheManager;
@@ -63,7 +65,7 @@ import org.springframework.context.annotation.Configuration;
 public class LoadBalancerCacheAutoConfiguration {
 
 	@Configuration(proxyBeanMethods = false)
-	@ConditionalOnMissingClass("com.github.benmanes.caffeine.cache.Caffeine")
+	@Conditional(OnCaffeineCacheMissingCondition.class)
 	protected static class LoadBalancerCacheManagerWarnConfiguration {
 
 		@Bean
@@ -83,14 +85,14 @@ public class LoadBalancerCacheAutoConfiguration {
 			if (LOG.isWarnEnabled()) {
 				LOG.warn(
 						"Spring Cloud LoadBalancer is currently working with the default cache. "
-								+ "You can switch to using Caffeine cache, by adding it to the classpath.");
+								+ "You can switch to using Caffeine cache, by adding it and org.springframework.cache.caffeine.CaffeineCacheManager to the classpath.");
 			}
 		}
 
 	}
 
 	@Configuration(proxyBeanMethods = false)
-	@ConditionalOnClass(Caffeine.class)
+	@ConditionalOnClass({ Caffeine.class, CaffeineCacheManager.class })
 	protected static class CaffeineLoadBalancerCacheManagerConfiguration {
 
 		@Bean(autowireCandidate = false)
@@ -103,7 +105,7 @@ public class LoadBalancerCacheAutoConfiguration {
 	}
 
 	@Configuration(proxyBeanMethods = false)
-	@ConditionalOnMissingClass("com.github.benmanes.caffeine.cache.Caffeine")
+	@Conditional(OnCaffeineCacheMissingCondition.class)
 	@ConditionalOnClass(ConcurrentMapWithTimedEviction.class)
 	protected static class DefaultLoadBalancerCacheManagerConfiguration {
 
@@ -116,4 +118,22 @@ public class LoadBalancerCacheAutoConfiguration {
 
 	}
 
+	static final class OnCaffeineCacheMissingCondition extends AnyNestedCondition {
+
+		private OnCaffeineCacheMissingCondition() {
+			super(ConfigurationPhase.REGISTER_BEAN);
+		}
+
+		@ConditionalOnMissingClass("com.github.benmanes.caffeine.cache.Caffeine")
+		static class CaffeineClassMissing {
+
+		}
+
+		@ConditionalOnMissingClass("org.springframework.cache.caffeine.CaffeineCacheManager")
+		static class CaffeineCacheManagerClassMissing {
+
+		}
+
+	}
+
 }

spring-cloud-loadbalancer/src/test/java/org/springframework/cloud/loadbalancer/config/LoadBalancerCacheAutoConfigurationTests.java

@@ -130,6 +130,24 @@ class LoadBalancerCacheAutoConfigurationTests {
 		});
 	}
 
+	@Test
+	void shouldUseDefaultCacheIfCaffeineCacheManagerNotInClasspath() {
+		ApplicationContextRunner contextRunner = noCaffeineCacheManagerRunner();
+
+		contextRunner.run(context -> {
+			assertThat(context.getBean(
+					LoadBalancerCacheAutoConfiguration.LoadBalancerCaffeineWarnLogger.class))
+							.isNotNull();
+			assertThat(context.getBeansOfType(CacheManager.class)).hasSize(1);
+			assertThat(((CacheManager) context.getBean("defaultLoadBalancerCacheManager"))
+					.getCacheNames()).hasSize(1);
+			assertThat(context.getBean("defaultLoadBalancerCacheManager"))
+					.isInstanceOf(DefaultLoadBalancerCacheManager.class);
+			assertThat(((CacheManager) context.getBean("defaultLoadBalancerCacheManager"))
+					.getCacheNames()).contains("CachingServiceInstanceListSupplierCache");
+		});
+	}
+
 	@Test
 	void defaultLoadBalancerCacheShouldNotOverrideCacheTypeSetting() {
 		ApplicationContextRunner contextRunner = noCaffeineRunner()
@@ -190,6 +208,11 @@ class LoadBalancerCacheAutoConfigurationTests {
 				.withClassLoader(new FilteredClassLoader(Caffeine.class));
 	}
 
+	private ApplicationContextRunner noCaffeineCacheManagerRunner() {
+		return baseApplicationRunner()
+				.withClassLoader(new FilteredClassLoader(CaffeineCacheManager.class));
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	@EnableCaching
 	static class TestConfiguration {