adding following modules with updated testcase : DB, Filter, Json (#1410)

* adding ratpack module

* adding pom.xml

* adding following modules with updated testcase : DB, Filter, Json

ratpack/src/test/java/com/baeldung/ApplicationTest.java

@@ -4,10 +4,17 @@ import org.junit.After;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
+import com.baeldung.model.Employee;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
 import ratpack.test.MainClassApplicationUnderTest;
 
 import static org.junit.Assert.assertEquals;
 
+import java.util.ArrayList;
+import java.util.List;
+
 @RunWith(JUnit4.class)
 public class ApplicationTest {
 
@@ -23,6 +30,16 @@ public class ApplicationTest {
 		assertEquals("Hello dummybot!!!", appUnderTest.getHttpClient().getText("/dummybot"));
 	}
 	
+	@Test
+	public void givenUrl_getListOfEmployee() throws JsonProcessingException {
+		List<Employee> employees = new ArrayList<Employee>();
+		ObjectMapper mapper = new ObjectMapper();
+		employees.add(new Employee(1L, "Mr", "John Doe"));
+		employees.add(new Employee(2L, "Mr", "White Snow"));
+		
+		assertEquals(mapper.writeValueAsString(employees), appUnderTest.getHttpClient().getText("/data/employees"));
+	}
+	
 	@After
 	public void shutdown() {
 		appUnderTest.close();