BAEL-3459 updated cache2k example and test cases (#8732)

libraries-3/src/main/java/com/baeldung/cache2k/ProductHelper.java

@@ -4,38 +4,33 @@ import java.util.Objects;
 
 import org.cache2k.Cache;
 import org.cache2k.Cache2kBuilder;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 public class ProductHelper {
 
-    final Logger LOGGER = LoggerFactory.getLogger(ProductHelper.class);
-
     private Cache<String, Integer> cachedDiscounts;
 
+    private int cacheMissCount = 0;
+
     public ProductHelper() {
         cachedDiscounts = Cache2kBuilder.of(String.class, Integer.class)
             .name("discount")
             .eternal(true)
             .entryCapacity(100)
             .build();
-
-        initDiscountCache("Sports", 20);
-    }
-
-    public void initDiscountCache(String productType, Integer value) {
-        cachedDiscounts.put(productType, value);
     }
 
     public Integer getDiscount(String productType) {
         Integer discount = cachedDiscounts.get(productType);
         if (Objects.isNull(discount)) {
-            LOGGER.info("Discount for {} not found.", productType);
+            cacheMissCount++;
-            discount = 0;
+            discount = "Sports".equalsIgnoreCase(productType) ? 20 : 10;
-        } else {
+            cachedDiscounts.put(productType, discount);
-            LOGGER.info("Discount for {} found.", productType);
         }
         return discount;
     }
 
+    public int getCacheMissCount() {
+        return cacheMissCount;
+    }
+
 }

libraries-3/src/main/java/com/baeldung/cache2k/ProductHelperUsingLoader.java

@@ -1,6 +1,5 @@
 package com.baeldung.cache2k;
 
-import java.util.Objects;
 import java.util.concurrent.TimeUnit;
 
 import org.cache2k.Cache;
@@ -14,28 +13,26 @@ public class ProductHelperUsingLoader {
 
     private Cache<String, Integer> cachedDiscounts;
 
+    private int cacheMissCount = 0;
+
     public ProductHelperUsingLoader() {
         cachedDiscounts = Cache2kBuilder.of(String.class, Integer.class)
             .name("discount-loader")
-            .eternal(false)
             .expireAfterWrite(10, TimeUnit.MILLISECONDS)
             .entryCapacity(100)
             .loader((key) -> {
-                LOGGER.info("Calculating discount for {}.", key);
+                cacheMissCount++;
                 return "Sports".equalsIgnoreCase(key) ? 20 : 10;
             })
             .build();
     }
 
     public Integer getDiscount(String productType) {
-        Integer discount = cachedDiscounts.get(productType);
+        return cachedDiscounts.get(productType);
-        if (Objects.isNull(discount)) {
+    }
-            LOGGER.info("Discount for {} not found.", productType);
+
-            discount = 0;
+    public int getCacheMissCount() {
-        } else {
+        return cacheMissCount;
-            LOGGER.info("Discount for {} found.", productType);
-        }
-        return discount;
     }
 
 }

libraries-3/src/main/java/com/baeldung/cache2k/ProductHelperWithEventListener.java

@@ -1,6 +1,5 @@
 package com.baeldung.cache2k;
 
-import java.util.Objects;
 import java.util.concurrent.TimeUnit;
 
 import org.cache2k.Cache;
@@ -16,14 +15,15 @@ public class ProductHelperWithEventListener {
 
     private Cache<String, Integer> cachedDiscounts;
 
+    private int cacheMissCount = 0;
+
     public ProductHelperWithEventListener() {
         cachedDiscounts = Cache2kBuilder.of(String.class, Integer.class)
             .name("discount-listener")
-            .eternal(false)
             .expireAfterWrite(10, TimeUnit.MILLISECONDS)
             .entryCapacity(100)
             .loader((key) -> {
-                LOGGER.info("Calculating discount for {}.", key);
+                cacheMissCount++;
                 return "Sports".equalsIgnoreCase(key) ? 20 : 10;
             })
             .addListener(new CacheEntryCreatedListener<String, Integer>() {
@@ -36,14 +36,11 @@ public class ProductHelperWithEventListener {
     }
 
     public Integer getDiscount(String productType) {
-        Integer discount = cachedDiscounts.get(productType);
+        return cachedDiscounts.get(productType);
-        if (Objects.isNull(discount)) {
+    }
-            LOGGER.info("Discount for {} not found.", productType);
+
-            discount = 0;
+    public int getCacheMissCount() {
-        } else {
+        return cacheMissCount;
-            LOGGER.info("Discount for {} found.", productType);
-        }
-        return discount;
     }
 
 }

libraries-3/src/main/java/com/baeldung/cache2k/ProductHelperWithExpiry.java

@@ -5,39 +5,34 @@ import java.util.concurrent.TimeUnit;
 
 import org.cache2k.Cache;
 import org.cache2k.Cache2kBuilder;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 public class ProductHelperWithExpiry {
 
-    final Logger LOGGER = LoggerFactory.getLogger(ProductHelperWithExpiry.class);
-
     private Cache<String, Integer> cachedDiscounts;
 
+    private int cacheMissCount = 0;
+
     public ProductHelperWithExpiry() {
         cachedDiscounts = Cache2kBuilder.of(String.class, Integer.class)
             .name("discount-expiry")
-            .eternal(false)
             .expireAfterWrite(5, TimeUnit.MILLISECONDS)
             .entryCapacity(100)
             .build();
 
-        initDiscountCache("Sports", 20);
-    }
-
-    public void initDiscountCache(String productType, Integer value) {
-        cachedDiscounts.put(productType, value);
     }
 
     public Integer getDiscount(String productType) {
         Integer discount = cachedDiscounts.get(productType);
         if (Objects.isNull(discount)) {
-            LOGGER.info("Discount for {} not found.", productType);
+            cacheMissCount++;
-            discount = 0;
+            discount = "Sports".equalsIgnoreCase(productType) ? 20 : 10;
-        } else {
+            cachedDiscounts.put(productType, discount);
-            LOGGER.info("Discount for {} found.", productType);
         }
         return discount;
     }
 
+    public int getCacheMissCount() {
+        return cacheMissCount;
+    }
+
 }

libraries-3/src/test/java/com/baeldung/cache2k/ProductHelperUnitTest.java

@@ -6,12 +6,13 @@ import org.junit.Test;
 
 public class ProductHelperUnitTest {
 
-    ProductHelper productHelper = new ProductHelper();
-
     @Test
-    public void whenInvokedGetDiscount_thenGetItFromCache() {
+    public void whenInvokedGetDiscountTwice_thenGetItFromCache() {
+        ProductHelper productHelper = new ProductHelper();
+        assertTrue(productHelper.getCacheMissCount() == 0);
         assertTrue(productHelper.getDiscount("Sports") == 20);
-        assertTrue(productHelper.getDiscount("Electronics") == 0);
+        assertTrue(productHelper.getDiscount("Sports") == 20);
+        assertTrue(productHelper.getCacheMissCount() == 1);
     }
 
 }

libraries-3/src/test/java/com/baeldung/cache2k/ProductHelperUsingLoaderUnitTest.java

@@ -6,12 +6,16 @@ import org.junit.Test;
 
 public class ProductHelperUsingLoaderUnitTest {
 
-    ProductHelperUsingLoader productHelper = new ProductHelperUsingLoader();
-
     @Test
-    public void whenInvokedGetDiscount_thenPopulateCache() {
+    public void whenInvokedGetDiscount_thenPopulateCacheUsingLoader() {
+        ProductHelperUsingLoader productHelper = new ProductHelperUsingLoader();
+        assertTrue(productHelper.getCacheMissCount() == 0);
+
         assertTrue(productHelper.getDiscount("Sports") == 20);
+        assertTrue(productHelper.getCacheMissCount() == 1);
+
         assertTrue(productHelper.getDiscount("Electronics") == 10);
+        assertTrue(productHelper.getCacheMissCount() == 2);
     }
 
 }

libraries-3/src/test/java/com/baeldung/cache2k/ProductHelperWithEventListenerUnitTest.java

@@ -6,10 +6,9 @@ import org.junit.Test;
 
 public class ProductHelperWithEventListenerUnitTest {
 
-    ProductHelperWithEventListener productHelper = new ProductHelperWithEventListener();
-
     @Test
     public void whenEntryAddedInCache_thenEventListenerCalled() {
+        ProductHelperWithEventListener productHelper = new ProductHelperWithEventListener();
         assertTrue(productHelper.getDiscount("Sports") == 20);
     }
 

libraries-3/src/test/java/com/baeldung/cache2k/ProductHelperWithExpiryUnitTest.java

@@ -6,13 +6,17 @@ import org.junit.Test;
 
 public class ProductHelperWithExpiryUnitTest {
 
-    ProductHelperWithExpiry productHelper = new ProductHelperWithExpiry();
-
     @Test
-    public void whenInvokedGetDiscountForExpiredProduct_thenNoDiscount() throws InterruptedException {
+    public void whenInvokedGetDiscountAfterExpiration_thenDiscountCalculatedAgain() throws InterruptedException {
+        ProductHelperWithExpiry productHelper = new ProductHelperWithExpiry();
+        assertTrue(productHelper.getCacheMissCount() == 0);
         assertTrue(productHelper.getDiscount("Sports") == 20);
+        assertTrue(productHelper.getCacheMissCount() == 1);
+
         Thread.sleep(20);
-        assertTrue(productHelper.getDiscount("Sports") == 0);
+
+        assertTrue(productHelper.getDiscount("Sports") == 20);
+        assertTrue(productHelper.getCacheMissCount() == 2);
     }
 
 }