modified the test cases and added integration test

src/test/java/com/nisum/offertransactionservice/controller/OfferTransactionControllerIntegrationTest.java

+package com.nisum.offertransactionservice.controller;
+
+import com.nisum.offertransactionservice.dto.Item;
+import com.nisum.offertransactionservice.dto.OfferTransactionRequest;
+import io.restassured.RestAssured;
+import org.hamcrest.Matchers;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static io.restassured.RestAssured.with;
+
+@SpringBootTest
+public class OfferTransactionControllerIntegrationTest {
+
+    @BeforeEach
+    public void setup() {
+        RestAssured.baseURI = "http:localhost";
+        RestAssured.port = 7072;
+    }
+
+
+    @Test
+    public void getOfferTransactionResponseTest() {
+        with().body(getOfferTransactionRequest())
+                .when()
+                .request("POST", "/offerTransactionCall")
+                .then()
+                .statusCode(200)
+                .body("offerTransactionCall.offerTransactionResponse.transactionId", Matchers.notNullValue());
+    }
+
+    private OfferTransactionRequest getOfferTransactionRequest() {
+        OfferTransactionRequest offerTransactionRequest = new OfferTransactionRequest();
+        offerTransactionRequest.setHhId(54321L);
+        offerTransactionRequest.setItemList(getItemList());
+        return offerTransactionRequest;
+    }
+
+    private List<Item> getItemList() {
+        List<Item> itemList = new ArrayList<>();
+        Item item1 = new Item("Coke", "12", 13.05);
+        Item item2 = new Item("Thumpsup", "11", 14.05);
+        itemList.add(item1);
+        itemList.add(item2);
+        return itemList;
+    }
+}

src/test/java/com/nisum/offertransactionservice/controller/OfferTransactionControllerTest.java

@@ -10,7 +10,10 @@ import com.nisum.offertransactionservice.model.OfferLookup;
 import com.nisum.offertransactionservice.model.OfferMeta;
 import com.nisum.offertransactionservice.service.OfferCallingPEService;
 import org.junit.jupiter.api.Test;
-import org.mockito.*;
+import org.mockito.ArgumentMatchers;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.Mockito;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.context.annotation.Description;
@@ -21,7 +24,7 @@ import java.time.LocalDateTime;
 import java.util.*;
 
 import static org.junit.Assert.assertEquals;
-import static org.mockito.Mockito.*;
+import static org.mockito.Mockito.when;
 
 @SpringBootTest
 class OfferTransactionControllerTest {