Upgrade to Ehcache 3

I saw on twitter the reference of an article (in french):
http://javaetmoi.com/2016/08/migrer-vers-spring-boot/

That article concludes with something along the lines of  "Besides the
EhCache and Maven configuration, Petclinic does not hold a single line
of XML anymore".

Looking at the code, we can remove more XML if you want. This PR migrates
the cache infrastructure to EhCache 3 and JCache (JSR-107). This also
reduces the number of dependencies.

pom.xml

@@ -59,10 +59,6 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
-        <dependency>
-            <groupId>org.springframework</groupId>
-            <artifactId>spring-context-support</artifactId>
-        </dependency>
 
         <dependency>
             <groupId>org.apache.tomcat.embed</groupId>
@@ -74,18 +70,6 @@
             <artifactId>jstl</artifactId>
         </dependency>
 
-
-        <!-- used for EhCacheCacheManager -->
-        <dependency>
-            <groupId>org.aspectj</groupId>
-            <artifactId>aspectjrt</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.aspectj</groupId>
-            <artifactId>aspectjweaver</artifactId>
-            <scope>runtime</scope>
-        </dependency>
-
         <!-- Date and Time -->
         <dependency>
             <groupId>joda-time</groupId>
@@ -123,14 +107,12 @@
 
         <!-- EhCache -->
         <dependency>
-            <groupId>net.sf.ehcache</groupId>
+            <groupId>javax.cache</groupId>
+            <artifactId>cache-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.ehcache</groupId>
             <artifactId>ehcache</artifactId>
-            <exclusions>
-                <exclusion>
-                    <groupId>commons-logging</groupId>
-                    <artifactId>commons-logging</artifactId>
-                </exclusion>
-            </exclusions>
         </dependency>
 
         <!-- Dandelion -->

src/main/java/org/springframework/samples/petclinic/config/CacheConfig.java

 package org.springframework.samples.petclinic.config;
 
+import java.util.concurrent.TimeUnit;
+import javax.cache.CacheManager;
+
+import org.ehcache.config.CacheConfiguration;
+import org.ehcache.config.builders.CacheConfigurationBuilder;
+import org.ehcache.config.builders.ResourcePoolsBuilder;
+import org.ehcache.config.units.EntryUnit;
+import org.ehcache.expiry.Duration;
+import org.ehcache.expiry.Expirations;
+import org.ehcache.jsr107.Eh107Configuration;
+
+import org.springframework.boot.autoconfigure.cache.JCacheManagerCustomizer;
 import org.springframework.cache.annotation.EnableCaching;
+import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Profile;
 
@@ -11,4 +24,21 @@ import org.springframework.context.annotation.Profile;
 @EnableCaching
 @Profile("production")
 public class CacheConfig {
+
+    @Bean
+    public JCacheManagerCustomizer cacheManagerCustomizer() {
+        return new JCacheManagerCustomizer() {
+            @Override
+            public void customize(CacheManager cacheManager) {
+                CacheConfiguration<Object, Object> config = CacheConfigurationBuilder
+                    .newCacheConfigurationBuilder(Object.class, Object.class,
+                        ResourcePoolsBuilder.newResourcePoolsBuilder()
+                            .heap(100, EntryUnit.ENTRIES))
+                    .withExpiry(Expirations.timeToLiveExpiration(Duration.of(60, TimeUnit.SECONDS)))
+                    .build();
+                cacheManager.createCache("vets", Eh107Configuration.fromEhcacheCacheConfiguration(config));
+            }
+        };
+    }
+
 }

src/main/resources/ehcache.xml

-<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:noNamespaceSchemaLocation="ehcache.xsd"
-         updateCheck="false">
-    <diskStore path="java.io.tmpdir"/>
-
-    <!-- objects are evicted from the cache every 60 seconds -->
-    <cache name="vets"
-           timeToLiveSeconds="60"
-           maxElementsInMemory="100"
-           eternal="false"
-           overflowToDisk="false"
-           maxElementsOnDisk="10000000"
-           diskPersistent="false"
-           diskExpiryThreadIntervalSeconds="1"
-           memoryStoreEvictionPolicy="LRU"/>
-
-</ehcache>