Replace GSON with Jackson

pom.xml

@@ -27,9 +27,9 @@
       <scope>test</scope>
     </dependency>
     <dependency>
-      <groupId>com.google.code.gson</groupId>
-      <artifactId>gson</artifactId>
-      <version>2.11.0</version>
+      <groupId>com.fasterxml.jackson.core</groupId>
+      <artifactId>jackson-databind</artifactId>
+      <version>2.18.2</version>
     </dependency>
     <dependency>
       <groupId>org.junit.jupiter</groupId>

src/test/java/org/openmrs/performance/http/DoctorHttpService.java

@@ -1,6 +1,7 @@
 package org.openmrs.performance.http;
 
-import com.google.gson.Gson;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
 import io.gatling.javaapi.http.HttpRequestActionBuilder;
 
 import java.time.ZonedDateTime;
@@ -79,7 +80,6 @@ public HttpRequestActionBuilder getAppointments(String patientUuid) {
 	}
 
 	public HttpRequestActionBuilder submitVisitForm(String patientUuid, String visitTypeUuid, String locationUuid) {
-		Gson gson = new Gson();
 		ZonedDateTime now = ZonedDateTime.now();
 		String startDateTime = now.format(DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSSZ"));
 
@@ -88,27 +88,34 @@ public HttpRequestActionBuilder submitVisitForm(String patientUuid, String visit
 		requestBodyMap.put("startDatetime", startDateTime);
 		requestBodyMap.put("visitType", visitTypeUuid);
 		requestBodyMap.put("location", locationUuid);
-
-		return http("Submit Visit Form")
-				.post("/openmrs/ws/rest/v1/visit")
-				.body(StringBody(gson.toJson(requestBodyMap)))
-				.check(jsonPath("$.uuid").saveAs("visitUuid"));
-	}
+
+        try {
+            return http("Submit Visit Form")
+                    .post("/openmrs/ws/rest/v1/visit")
+                    .body(StringBody(new ObjectMapper().writeValueAsString(requestBodyMap)))
+                    .check(jsonPath("$.uuid").saveAs("visitUuid"));
+        } catch (JsonProcessingException e) {
+            throw new RuntimeException(e);
+        }
+    }
 
 	public HttpRequestActionBuilder submitEndVisit(String visitUuid, String locationUuid, String visitTypeUuid) {
-		Gson gson = new Gson();
 		ZonedDateTime now = ZonedDateTime.now();
 		String formattedStopDateTime = now.format(DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSSZ"));
 
 		Map<String, String> requestBodyMap = new HashMap<>();
 		requestBodyMap.put("location", locationUuid);
 		requestBodyMap.put("visitType", visitTypeUuid);
 		requestBodyMap.put("stopDatetime", formattedStopDateTime);
-
-		return http("End Visit")
-				.post("/openmrs/ws/rest/v1/visit/" + visitUuid)
-				.body(StringBody(gson.toJson(requestBodyMap)));
-	}
+
+        try {
+            return http("End Visit")
+                    .post("/openmrs/ws/rest/v1/visit/" + visitUuid)
+                    .body(StringBody(new ObjectMapper().writeValueAsString(requestBodyMap)));
+        } catch (JsonProcessingException e) {
+            throw new RuntimeException(e);
+        }
+    }
 
 	public HttpRequestActionBuilder getOrderTypes() {
 		return http("Get Order Types")
@@ -224,12 +231,13 @@ public HttpRequestActionBuilder saveOrder(String patientUuid, String visitUuid,
 		encounter.put("visit", visitUuid);
 		encounter.put("obs", new Object[0]);
 		encounter.put("orders", new Object[] { order });
-
-		Gson gson = new Gson();
-		String body = gson.toJson(encounter);
-
-		return http("Save Drug Order")
-				.post("/openmrs/ws/rest/v1/encounter")
-				.body(StringBody(body));
-	}
+
+        try {
+            return http("Save Drug Order")
+                    .post("/openmrs/ws/rest/v1/encounter")
+                    .body(StringBody(new ObjectMapper().writeValueAsString(encounter)));
+        } catch (JsonProcessingException e) {
+            throw new RuntimeException(e);
+        }
+    }
 }

src/test/java/org/openmrs/performance/utils/CommonUtils.java

@@ -1,25 +1,37 @@
 package org.openmrs.performance.utils;
 
-import com.google.gson.JsonArray;
-import com.google.gson.JsonObject;
-import com.google.gson.JsonParser;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
 
 public class CommonUtils {
 
 	public static List<String> extractConceptIds(String response) {
 		List<String> conceptIds = new ArrayList<>();
-		JsonObject jsonObject = JsonParser.parseString(response).getAsJsonObject();
-		JsonArray entries = jsonObject.getAsJsonArray("entry");
 
-		for (int i = 0; i < entries.size(); i++) {
-			JsonObject resource = entries.get(i).getAsJsonObject().getAsJsonObject("resource");
-			JsonArray coding = resource.getAsJsonObject("code").getAsJsonArray("coding");
-			conceptIds.add(coding.get(0).getAsJsonObject().get("code").getAsString());
+		try {
+			ObjectMapper objectMapper = new ObjectMapper();
+			JsonNode jsonObject = objectMapper.readTree(response);
+			JsonNode entries = jsonObject.get("entry");
+
+			if (entries != null && entries.isArray()) {
+				return StreamSupport.stream(entries.spliterator(), false)
+						.map(entry -> entry.get("resource"))
+						.filter(Objects::nonNull)
+						.map(resource -> resource.path("code").path("coding"))
+						.filter(coding -> coding.isArray() && !coding.isEmpty())
+						.map(coding -> coding.get(0).get("code").asText())
+						.collect(Collectors.toList());
+			}
+		} catch (Exception e) {
+			throw new RuntimeException(e);
 		}
-		
+
 		return conceptIds;
 	}