Fix SSL metrics for dynamically registered bundles

Also add regression test and adjust imports in SslMeterBinderTests.

Author: TerryTaoYY

module/spring-boot-micrometer-metrics/src/test/java/org/springframework/boot/micrometer/metrics/autoconfigure/ssl/SslMeterBinderTests.java

@@ -20,6 +20,8 @@
 import java.time.Duration;
 import java.time.Instant;
 import java.time.ZoneId;
+import java.util.Collections;
+import java.util.List;
 
 import io.micrometer.core.instrument.MeterRegistry;
 import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
@@ -34,12 +36,10 @@
 import org.springframework.boot.ssl.jks.JksSslStoreDetails;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import java.util.List;
-
+import static org.mockito.BDDMockito.given;
+import static org.mockito.BDDMockito.then;
 import static org.mockito.Mockito.atLeast;
 import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
 
 /**
  * Tests for {@link SslMeterBinder}.
@@ -73,25 +73,25 @@ void shouldRegisterChainExpiryMetrics() {
 	void shouldWatchUpdatesForBundlesRegisteredAfterConstruction() {
 		DefaultSslBundleRegistry sslBundleRegistry = new DefaultSslBundleRegistry();
 		SslInfo sslInfo = mock(SslInfo.class);
-		when(sslInfo.getBundles()).thenReturn(List.of());
+		given(sslInfo.getBundles()).willReturn(Collections.emptyList());
 
 		SslInfo.BundleInfo bundleInfo = mock(SslInfo.BundleInfo.class);
 		SslInfo.CertificateChainInfo chainInfo = mock(SslInfo.CertificateChainInfo.class);
 		SslInfo.CertificateInfo certificateInfo = mock(SslInfo.CertificateInfo.class);
 		SslInfo.CertificateValidityInfo validityInfo = mock(SslInfo.CertificateValidityInfo.class);
 
-		when(sslInfo.getBundle("dynamic")).thenReturn(bundleInfo);
-		when(bundleInfo.getName()).thenReturn("dynamic");
-		when(bundleInfo.getCertificateChains()).thenReturn(List.of(chainInfo));
-		when(chainInfo.getAlias()).thenReturn("server");
-		when(chainInfo.getCertificates()).thenReturn(List.of(certificateInfo));
-		when(certificateInfo.getSerialNumber()).thenReturn("serial");
+		given(sslInfo.getBundle("dynamic")).willReturn(bundleInfo);
+		given(bundleInfo.getName()).willReturn("dynamic");
+		given(bundleInfo.getCertificateChains()).willReturn(List.of(chainInfo));
+		given(chainInfo.getAlias()).willReturn("server");
+		given(chainInfo.getCertificates()).willReturn(List.of(certificateInfo));
+		given(certificateInfo.getSerialNumber()).willReturn("serial");
 
 		Instant expiry = CLOCK.instant().plus(Duration.ofDays(365));
-		when(certificateInfo.getValidityEnds()).thenReturn(expiry);
-		when(certificateInfo.getValidity()).thenReturn(validityInfo);
-		when(validityInfo.getStatus()).thenReturn(SslInfo.CertificateValidityInfo.Status.VALID);
-		when(validityInfo.getMessage()).thenReturn(null);
+		given(certificateInfo.getValidityEnds()).willReturn(expiry);
+		given(certificateInfo.getValidity()).willReturn(validityInfo);
+		given(validityInfo.getStatus()).willReturn(SslInfo.CertificateValidityInfo.Status.VALID);
+		given(validityInfo.getMessage()).willReturn(null);
 
 		SslMeterBinder binder = new SslMeterBinder(sslInfo, sslBundleRegistry, CLOCK);
 		SimpleMeterRegistry meterRegistry = new SimpleMeterRegistry();
@@ -101,7 +101,7 @@ void shouldWatchUpdatesForBundlesRegisteredAfterConstruction() {
 		sslBundleRegistry.registerBundle("dynamic", bundle);
 		sslBundleRegistry.updateBundle("dynamic", bundle);
 
-		verify(sslInfo, atLeast(2)).getBundle("dynamic");
+		then(sslInfo).should(atLeast(2)).getBundle("dynamic");
 	}
 
 	private static long findExpiryGauge(MeterRegistry meterRegistry, String chain, String certificateSerialNumber) {