BAEL-2569 : EnvironmentPostProcessor in Spring Boot (#6479)

* BAEL-2569 : EnvironmentPostProcessor in Spring Boot

* BAEL-2569 add test

* BAEL-2569 update test

spring-boot/src/test/java/com/baeldung/environmentpostprocessor/PriceCalculationEnvironmentPostProcessorLiveTest.java

@@ -0,0 +1,26 @@
+package com.baeldung.environmentpostprocessor;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import com.baeldung.environmentpostprocessor.service.PriceCalculationService;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(classes = PriceCalculationApplication.class)
+public class PriceCalculationEnvironmentPostProcessorLiveTest {
+
+    @Autowired
+    PriceCalculationService pcService;
+
+    @Test
+    public void whenSetNetEnvironmentVariablebyDefault_thenNoTaxApplied() {
+        double total = pcService.productTotalPrice(100, 4);
+        assertEquals(400.0, total, 0);
+    }
+
+}