Add two level of caching

spring-boot-modules/spring-caching-2/src/main/java/com/baeldung/caching/multicache/CacheConfig.java

@@ -0,0 +1,90 @@
+package com.baeldung.caching.multicache;
+
+import com.github.benmanes.caffeine.cache.Caffeine;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.cache.CacheManager;
+import org.springframework.cache.annotation.AnnotationCacheOperationSource;
+import org.springframework.cache.annotation.EnableCaching;
+import org.springframework.cache.caffeine.CaffeineCache;
+import org.springframework.cache.interceptor.CacheInterceptor;
+import org.springframework.cache.interceptor.CacheOperationSource;
+import org.springframework.cache.support.SimpleCacheManager;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Primary;
+import org.springframework.data.redis.cache.RedisCacheConfiguration;
+import org.springframework.data.redis.cache.RedisCacheManager;
+import org.springframework.data.redis.connection.RedisConnectionFactory;
+import org.springframework.data.redis.connection.RedisStandaloneConfiguration;
+import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
+import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
+import org.springframework.data.redis.serializer.RedisSerializationContext;
+
+import java.time.Duration;
+import java.util.Arrays;
+
+@Configuration
+@EnableCaching
+public class CacheConfig {
+
+    @Value("${spring.redis.host}")
+    private String redisHost;
+
+    @Value("${spring.redis.port}")
+    private int redisPort;
+
+    @Bean
+    public CaffeineCache caffeineCacheConfig() {
+        return new CaffeineCache("customerCache", Caffeine.newBuilder()
+                .expireAfterWrite(Duration.ofMinutes(1))
+                .initialCapacity(1)
+                .maximumSize(2000)
+                .build());
+    }
+
+    @Bean
+    @Primary
+    public CacheManager caffeineCacheManager() {
+        SimpleCacheManager manager = new SimpleCacheManager();
+        manager.setCaches(Arrays.asList(
+                caffeineCacheConfig()));
+        return manager;
+    }
+
+    @Bean
+    public CacheManager redisCacheManager() {
+        return RedisCacheManager.RedisCacheManagerBuilder
+                .fromConnectionFactory(redisConnectionFactory())
+                .withCacheConfiguration("customerCache", cacheConfiguration())
+                .build();
+    }
+
+    @Bean
+    public RedisConnectionFactory redisConnectionFactory() {
+        RedisStandaloneConfiguration redisStandaloneConfiguration = new RedisStandaloneConfiguration();
+        redisStandaloneConfiguration.setHostName(redisHost);
+        redisStandaloneConfiguration.setPort(redisPort);
+        return new LettuceConnectionFactory(redisStandaloneConfiguration);
+    }
+
+    @Bean
+    public RedisCacheConfiguration cacheConfiguration() {
+        return RedisCacheConfiguration.defaultCacheConfig()
+                .entryTtl(Duration.ofMinutes(60))
+                .disableCachingNullValues()
+                .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(new GenericJackson2JsonRedisSerializer()));
+    }
+
+    @Bean
+    public CacheInterceptor cacheInterceptor() {
+        CacheInterceptor interceptor = new CustomerCacheInterceptor(caffeineCacheManager());
+        interceptor.setCacheOperationSources(cacheOperationSource());
+        return interceptor;
+    }
+
+    @Bean
+    public CacheOperationSource cacheOperationSource() {
+        return new AnnotationCacheOperationSource();
+    }
+
+}

spring-boot-modules/spring-caching-2/src/main/java/com/baeldung/caching/multicache/Customer.java

@@ -0,0 +1,21 @@
+package com.baeldung.caching.multicache;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import java.io.Serializable;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+@Setter
+public class Customer implements Serializable {
+
+    private String id;
+
+    private String name;
+
+    private String email;
+}

spring-boot-modules/spring-caching-2/src/main/java/com/baeldung/caching/multicache/CustomerCacheInterceptor.java

@@ -0,0 +1,30 @@
+package com.baeldung.caching.multicache;
+
+import org.springframework.cache.Cache;
+import org.springframework.cache.CacheManager;
+import org.springframework.cache.interceptor.CacheInterceptor;
+import org.springframework.data.redis.cache.RedisCache;
+
+public class CustomerCacheInterceptor extends CacheInterceptor {
+
+    private final CacheManager caffeineCacheManager;
+
+    public CustomerCacheInterceptor(CacheManager caffeineCacheManager) {
+        this.caffeineCacheManager = caffeineCacheManager;
+    }
+
+    @Override
+    protected Cache.ValueWrapper doGet(Cache cache, Object key) {
+        Cache.ValueWrapper existingCacheValue = super.doGet(cache, key);
+
+        if (cache.getClass() == RedisCache.class) {
+            Cache caffeineCache = caffeineCacheManager.getCache(cache.getName());
+            if (existingCacheValue != null && caffeineCache != null && caffeineCache.get(key) == null) {
+                caffeineCache.putIfAbsent(key, existingCacheValue.get());
+            }
+        }
+
+        return existingCacheValue;
+    }
+}
+

spring-boot-modules/spring-caching-2/src/main/java/com/baeldung/caching/multicache/CustomerController.java

@@ -0,0 +1,22 @@
+package com.baeldung.caching.multicache;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class CustomerController {
+
+    private final CustomerService customerService;
+
+    @Autowired
+    public CustomerController(CustomerService customerService) {
+        this.customerService = customerService;
+    }
+
+    @GetMapping("/customer/{id}")
+    public Customer getCustomer(@PathVariable String id) {
+        return customerService.getCustomer(id);
+    }
+}

spring-boot-modules/spring-caching-2/src/main/java/com/baeldung/caching/multicache/CustomerRepository.java

@@ -0,0 +1,44 @@
+package com.baeldung.caching.multicache;
+
+import org.springframework.stereotype.Service;
+
+import javax.annotation.PostConstruct;
+import java.util.HashMap;
+import java.util.Map;
+
+@Service
+public class CustomerRepository {
+
+    private final Map<String, Customer> customerMap = new HashMap<>();
+
+    public Customer getCustomerById(String id) {
+        return customerMap.get(id);
+    }
+
+    @PostConstruct
+    private void setupCustomerRepo() {
+        Customer product1 = getCustomer("100001", "name1", "name1@mail.com");
+        customerMap.put("100001", product1);
+
+        Customer product2 = getCustomer("100002", "name2", "name2@mail.com");
+        customerMap.put("100002", product2);
+
+        Customer product3 = getCustomer("100003", "name3", "name3@mail.com");
+        customerMap.put("100003", product3);
+
+        Customer product4 = getCustomer("100004", "name4", "name4@mail.com");
+        customerMap.put("100004", product4);
+
+        Customer product5 = getCustomer("100005", "name5", "name5@mail.com");
+        customerMap.put("100005", product5);
+    }
+
+    private static Customer getCustomer(String id, String name, String email) {
+        Customer customer = new Customer();
+        customer.setId(id);
+        customer.setName(name);
+        customer.setEmail(email);
+
+        return customer;
+    }
+}

spring-boot-modules/spring-caching-2/src/main/java/com/baeldung/caching/multicache/CustomerService.java

@@ -0,0 +1,25 @@
+package com.baeldung.caching.multicache;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.cache.annotation.Cacheable;
+import org.springframework.cache.annotation.Caching;
+import org.springframework.stereotype.Service;
+
+@Service
+public class CustomerService {
+
+    private final CustomerRepository customerRepository;
+
+    @Autowired
+    public CustomerService(CustomerRepository customerRepository) {
+        this.customerRepository = customerRepository;
+    }
+
+    @Caching(cacheable = {
+            @Cacheable(cacheNames = "customerCache", cacheManager = "caffeineCacheManager"),
+            @Cacheable(cacheNames = "customerCache", cacheManager = "redisCacheManager")
+    })
+    public Customer getCustomer(String id) {
+        return customerRepository.getCustomerById(id);
+    }
+}

spring-boot-modules/spring-caching-2/src/main/java/com/baeldung/caching/multicache/MultipleCachingApplication.java

@@ -0,0 +1,12 @@
+package com.baeldung.caching.multicache;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class MultipleCachingApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(MultipleCachingApplication.class, args);
+    }
+}

spring-boot-modules/spring-caching-2/src/main/resources/application.properties

@@ -9,5 +9,6 @@ spring.jpa.hibernate.ddl-auto=update
 #setting cache TTL
 caching.spring.hotelListTTL=43200
 # Connection details
-#spring.redis.host=localhost
+spring.redis.host=localhost
-#spring.redis.port=6379
+spring.redis.port=6379
+spring.main.allow-bean-definition-overriding=true