Merge branch '3.4.x'

Closes gh-45015

Author: mhalbritter

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/ssl/SslHealthIndicator.java

@@ -28,19 +28,23 @@
 import org.springframework.boot.info.SslInfo.BundleInfo;
 import org.springframework.boot.info.SslInfo.CertificateChainInfo;
 import org.springframework.boot.info.SslInfo.CertificateInfo;
+import org.springframework.util.Assert;
 
 /**
  * {@link HealthIndicator} that checks the certificates the application uses and reports
  * {@link Status#OUT_OF_SERVICE} when a certificate is invalid.
  *
  * @author Jonatan Ivanov
+ * @author Young Jae You
  * @since 3.4.0
  */
 public class SslHealthIndicator extends AbstractHealthIndicator {
 
 	private final SslInfo sslInfo;
 
 	public SslHealthIndicator(SslInfo sslInfo) {
+		super("SSL health check failed");
+		Assert.notNull(sslInfo, "'sslInfo' must not be null");
 		this.sslInfo = sslInfo;
 	}