Additional setup to support native image creation.

- Switch to Caffeine for caching since it is supported on native unlike Ehcache
 - Use latest metadata repository 0.2.3 (will be the default with Native Build Tools 0.9.15)
 - Registers resource hints for WebJars and db resource directory

pom.xml

@@ -84,9 +84,8 @@
       <artifactId>cache-api</artifactId>
     </dependency>
     <dependency>
-      <groupId>org.ehcache</groupId>
-      <artifactId>ehcache</artifactId>
-      <classifier>jakarta</classifier>
+      <groupId>com.github.ben-manes.caffeine</groupId>
+      <artifactId>caffeine</artifactId>
     </dependency>
 
     <!-- webjars -->

src/main/java/org/springframework/samples/petclinic/PetClinicApplication.java

@@ -18,6 +18,7 @@ package org.springframework.samples.petclinic;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.ImportRuntimeHints;
 
 /**
  * PetClinic Spring Boot Application.
@@ -26,6 +27,7 @@ import org.springframework.boot.autoconfigure.SpringBootApplication;
  *
  */
 @SpringBootApplication
+@ImportRuntimeHints(PetClinicRuntimeHints.class)
 public class PetClinicApplication {
 
 	public static void main(String[] args) {

src/main/java/org/springframework/samples/petclinic/PetClinicRuntimeHints.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.samples.petclinic;
+
+import org.springframework.aot.hint.RuntimeHints;
+import org.springframework.aot.hint.RuntimeHintsRegistrar;
+
+public class PetClinicRuntimeHints implements RuntimeHintsRegistrar {
+
+	@Override
+	public void registerHints(RuntimeHints hints, ClassLoader classLoader) {
+		hints.resources().registerPattern("db/*"); // https://github.com/spring-projects/spring-boot/issues/32654
+		hints.resources().registerPattern("META-INF/resources/webjars/*");
+	}
+
+}