Merge branch '3.4.x' into 3.5.x

Closes gh-48056

Author: wilkinsona

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/cache/CacheMeterBinderProvidersConfiguration.java

@@ -30,6 +30,7 @@
 import org.springframework.boot.actuate.metrics.cache.JCacheCacheMeterBinderProvider;
 import org.springframework.boot.actuate.metrics.cache.RedisCacheMeterBinderProvider;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.cache.caffeine.CaffeineCache;
 import org.springframework.cache.jcache.JCacheCache;
 import org.springframework.context.annotation.Bean;
@@ -80,6 +81,7 @@ HazelcastCacheMeterBinderProvider hazelcastCacheMeterBinderProvider() {
 
 	@Configuration(proxyBeanMethods = false)
 	@ConditionalOnClass({ JCacheCache.class, javax.cache.CacheManager.class })
+	@ConditionalOnMissingBean(JCacheCacheMeterBinderProvider.class)
 	static class JCacheCacheMeterBinderProviderConfiguration {
 
 		@Bean

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/cache/CacheMetricsAutoConfigurationTests.java

@@ -24,6 +24,7 @@
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.actuate.autoconfigure.metrics.test.MetricsRun;
+import org.springframework.boot.actuate.metrics.cache.JCacheCacheMeterBinderProvider;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
@@ -113,6 +114,23 @@ void customCacheManagersAreInstrumented() {
 			});
 	}
 
+	@Test
+	void jcacheCacheMeterBinderProviderIsAutoConfigured() {
+		this.contextRunner.withPropertyValues("spring.cache.type=simple", "spring.cache.cache-names=cache1,cache2")
+			.run((context) -> assertThat(context).hasSingleBean(JCacheCacheMeterBinderProvider.class)
+				.hasBean("jCacheCacheMeterBinderProvider"));
+	}
+
+	@Test
+	void jcacheCacheMeterBinderProviderBacksOff() {
+		this.contextRunner.withPropertyValues("spring.cache.type=simple", "spring.cache.cache-names=cache1,cache2")
+			.withBean("customProvider", JCacheCacheMeterBinderProvider.class,
+					() -> new JCacheCacheMeterBinderProvider(true))
+			.run((context) -> assertThat(context).hasSingleBean(JCacheCacheMeterBinderProvider.class)
+				.hasBean("customProvider")
+				.doesNotHaveBean("jCacheCacheMeterBinderProvider"));
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	static class CustomCacheManagersConfiguration implements CachingConfigurer {
 

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/cache/JCacheCacheMeterBinderProvider.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.actuate.metrics.cache;
 
+import io.micrometer.core.instrument.FunctionCounter;
+import io.micrometer.core.instrument.Gauge;
 import io.micrometer.core.instrument.Tag;
 import io.micrometer.core.instrument.binder.MeterBinder;
 import io.micrometer.core.instrument.binder.cache.JCacheMetrics;
@@ -30,9 +32,33 @@
  */
 public class JCacheCacheMeterBinderProvider implements CacheMeterBinderProvider<JCacheCache> {
 
+	private final boolean registerCacheRemovalsAsFunctionCounter;
+
+	/**
+	 * Creates a {@code JCacheCacheMeterBinderProvider} that registers cache removals as a
+	 * {@link Gauge}.
+	 */
+	public JCacheCacheMeterBinderProvider() {
+		this(false);
+	}
+
+	/**
+	 * Creates a {@code JCacheCacheMeterBinderProvider} that registers cache removals with
+	 * a meter type that depends on the value of
+	 * {@code registerCacheRemovalsAsFunctionCounter}. When {@code false}, cache removals
+	 * are registered as a {@link Gauge}. When {@code true}, cache removals are registered
+	 * as a {@link FunctionCounter}.
+	 * @param registerCacheRemovalsAsFunctionCounter whether to register removals as a
+	 * gauge or a function counter
+	 * @since 3.4.12
+	 */
+	public JCacheCacheMeterBinderProvider(boolean registerCacheRemovalsAsFunctionCounter) {
+		this.registerCacheRemovalsAsFunctionCounter = registerCacheRemovalsAsFunctionCounter;
+	}
+
 	@Override
 	public MeterBinder getMeterBinder(JCacheCache cache, Iterable<Tag> tags) {
-		return new JCacheMetrics<>(cache.getNativeCache(), tags);
+		return new JCacheMetrics<>(cache.getNativeCache(), tags, this.registerCacheRemovalsAsFunctionCounter);
 	}
 
 }

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/cache/JCacheCacheMeterBinderProviderTests.java

@@ -53,6 +53,20 @@ void jCacheCacheProvider() throws URISyntaxException {
 		JCacheCache cache = new JCacheCache(this.nativeCache);
 		MeterBinder meterBinder = new JCacheCacheMeterBinderProvider().getMeterBinder(cache, Collections.emptyList());
 		assertThat(meterBinder).isInstanceOf(JCacheMetrics.class);
+		assertThat(meterBinder).extracting("registerCacheRemovalsAsFunctionCounter").isEqualTo(false);
+	}
+
+	@Test
+	void jCacheCacheProviderRegisteringRemovalsAsAFunctionCounter() throws URISyntaxException {
+		javax.cache.CacheManager cacheManager = mock(javax.cache.CacheManager.class);
+		given(cacheManager.getURI()).willReturn(new URI("/test"));
+		given(this.nativeCache.getCacheManager()).willReturn(cacheManager);
+		given(this.nativeCache.getName()).willReturn("test");
+		JCacheCache cache = new JCacheCache(this.nativeCache);
+		MeterBinder meterBinder = new JCacheCacheMeterBinderProvider(true).getMeterBinder(cache,
+				Collections.emptyList());
+		assertThat(meterBinder).isInstanceOf(JCacheMetrics.class);
+		assertThat(meterBinder).extracting("registerCacheRemovalsAsFunctionCounter").isEqualTo(true);
 	}
 
 }