Added a test case for the cache view

aksw-commons-utils-parent/aksw-commons-utils/src/main/java/org/aksw/commons/util/cache/CacheView.java

@@ -27,7 +27,7 @@
  * @param <KB> The backend key type
  * @param <V> The value type
  */
-public class CacheView<KF,KB, V>
+public class CacheView<KF, KB, V>
     implements Cache<KF, V>
 {
     /** The delegate cache*/

aksw-commons-utils-parent/aksw-commons-utils/src/test/java/org/aksw/commons/util/cache/TestCacheView.java

@@ -0,0 +1,41 @@
+package org.aksw.commons.util.cache;
+
+import java.util.Map;
+import java.util.Map.Entry;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.google.common.base.Converter;
+import com.google.common.cache.Cache;
+import com.google.common.cache.CacheBuilder;
+
+public class TestCacheView {
+    @Test
+    public void testCacheView() {
+        Cache<Entry<String, Integer>, String> sharedCache = CacheBuilder.newBuilder().build();
+
+        Converter<Integer, Entry<String, Integer>> convA = Converter.from(i -> Map.entry("a", i), Entry::getValue);
+        Converter<Integer, Entry<String, Integer>> convB = Converter.from(i -> Map.entry("b", i), Entry::getValue);
+
+        Cache<Integer, String> cacheA = new CacheView<>(sharedCache, convA, e -> "a".equals(e.getKey()));
+        Cache<Integer, String> cacheB = new CacheView<>(sharedCache, convB, e -> "b".equals(e.getKey()));
+
+        for (int i = 0; i < 3; ++i) {
+            int v = i;
+            CacheUtils.get(cacheA, v, () -> "a" + v);
+        }
+
+        for (int j = 0; j < 3; ++j) {
+            int v = j;
+            CacheUtils.get(cacheB, v, () -> "b" + v);
+        }
+
+        Assert.assertEquals("a1", cacheA.getIfPresent(1));
+        Assert.assertEquals("b2", cacheB.getIfPresent(2));
+
+        // System.out.println(sharedCache.asMap());
+        // System.out.println(CacheUtils.getIfPresent(cacheA, 2));
+        // System.out.println(CacheUtils.getIfPresent(cacheB, 2));
+    }
+}