BAEL-2303 Added sample code to demo how to replace multiple if statements in java.

core-java-8/src/test/java/com/baeldung/reduceIfelse/RuleEngineUnitTest.java

@@ -0,0 +1,27 @@
+package com.baeldung.reduceIfelse;
+
+import com.baeldung.reducingIfElse.Expression;
+import com.baeldung.reducingIfElse.Operator;
+import com.baeldung.reducingIfElse.Rule;
+import com.baeldung.reducingIfElse.RuleEngine;
+import org.junit.Test;
+
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+public class RuleEngineUnitTest {
+
+    @Test
+    public void whenNumbersGivenToRuleEngine_thenReturnCorrectResult() {
+        Expression expression = new Expression(5, 5, Operator.ADD);
+        RuleEngine engine = new RuleEngine();
+        List<Rule> rules = engine.process(expression);
+
+        assertNotNull(rules);
+        assertEquals(1, rules.size());
+        assertEquals(10, rules.get(0)
+            .getResult());
+    }
+}