Development: Unify json usage

docs/dev/guidelines/server.rst

@@ -648,3 +648,10 @@ Now, instead of mocking the whole Service, we can just mock the static method, l
 You should notice here that we can avoid the use of a Bean and also test deeper. Instead of mocking the uppermost method we only throw the exception at the place where it could actually happen. Very important to mention is that you need to close the mock at the end of the test again.
 
 For a real example where a SpyBean was replaced with a static mock look at the SubmissionExportIntegrationTest.java in `here <https://github.com/ls1intum/Artemis/commit/4843137aa01cfdf27ea019400c48df00df36ed45>`__.
+
+27. Avoid Arbitrary JSON Parsing Libraries
+==========================================
+
+* Utilize well-established JSON parsing libraries such as Gson or Jackson.
+* Whenever possible, use ObjectMapper for JSON parsing. If ObjectMapper is not suitable for the specific task, use to Gson's JsonParser.
+* By adhering to these points, we ensure to maintain a consistent and reliable approach to JSON parsing. This helps reduce potential maintenance challenges and compatibility issues.

src/main/java/de/tum/in/www1/artemis/domain/lti/Lti13AgsClaim.java

@@ -4,8 +4,7 @@
 
 import org.springframework.security.oauth2.core.oidc.OidcIdToken;
 
-import com.nimbusds.jose.shaded.json.JSONArray;
-import com.nimbusds.jose.shaded.json.JSONObject;
+import com.google.gson.*;
 
 /**
  * A wrapper class for an LTI 1.3 Assignment and Grading Services Claim. We support the Score Publishing Service in order to transmit scores.
@@ -23,23 +22,23 @@
      * @return an Ags-Claim if one was present in idToken.
      */
     public static Optional<Lti13AgsClaim> from(OidcIdToken idToken) {
-        JSONObject agsClaimJson = idToken.getClaim(Claims.AGS_CLAIM);
+        JsonObject agsClaimJson = JsonParser.parseString(idToken.getClaim(Claims.AGS_CLAIM).toString()).getAsJsonObject();
         if (agsClaimJson == null) {
             return Optional.empty();
         }
 
         Lti13AgsClaim agsClaim = new Lti13AgsClaim();
-        JSONArray scopes = (JSONArray) agsClaimJson.get("scope");
+        JsonArray scopes = agsClaimJson.get("scope").getAsJsonArray();
 
         if (scopes == null) {
             return Optional.empty();
         }
 
-        if (scopes.contains(Scopes.AGS_SCORE)) {
+        if (scopes.contains(new JsonPrimitive(Scopes.AGS_SCORE))) {
             agsClaim.setScope(Collections.singletonList(Scopes.AGS_SCORE));
         }
 
-        agsClaim.setLineItem((String) agsClaimJson.get("lineitem"));
+        agsClaim.setLineItem(agsClaimJson.get("lineitem").getAsString());
 
         return Optional.of(agsClaim);
     }

src/main/java/de/tum/in/www1/artemis/domain/lti/Lti13LaunchRequest.java

@@ -3,7 +3,8 @@
 import org.springframework.security.oauth2.core.oidc.OidcIdToken;
 import org.springframework.util.Assert;
 
-import com.nimbusds.jose.shaded.json.JSONObject;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
 
 public class Lti13LaunchRequest {
 
@@ -24,8 +25,8 @@
         this.sub = ltiIdToken.getClaim("sub");
         this.deploymentId = ltiIdToken.getClaim(Claims.LTI_DEPLOYMENT_ID);
 
-        JSONObject resourceLinkClaim = ltiIdToken.getClaim(Claims.RESOURCE_LINK);
-        this.resourceLinkId = resourceLinkClaim != null ? (String) resourceLinkClaim.get("id") : null;
+        JsonObject resourceLinkClaim = JsonParser.parseString(ltiIdToken.getClaim(Claims.RESOURCE_LINK).toString()).getAsJsonObject();
+        this.resourceLinkId = resourceLinkClaim != null ? resourceLinkClaim.get("id").getAsString() : null;
         this.targetLinkUri = ltiIdToken.getClaim(Claims.TARGET_LINK_URI);
 
         this.agsClaim = Lti13AgsClaim.from(ltiIdToken).orElse(null);

src/main/java/de/tum/in/www1/artemis/security/lti/Lti13LaunchFilter.java

@@ -19,9 +19,10 @@
 import org.springframework.web.filter.OncePerRequestFilter;
 import org.springframework.web.util.UriComponentsBuilder;
 
+import com.google.gson.JsonObject;
+
 import de.tum.in.www1.artemis.domain.lti.Claims;
 import de.tum.in.www1.artemis.service.connectors.lti.Lti13Service;
-import net.minidev.json.JSONObject;
 import uk.ac.ox.ctl.lti13.security.oauth2.client.lti.authentication.OidcAuthenticationToken;
 import uk.ac.ox.ctl.lti13.security.oauth2.client.lti.web.OAuth2LoginAuthenticationFilter;
 
@@ -90,8 +91,8 @@ private void writeResponse(String targetLinkUri, HttpServletResponse response) t
         UriComponentsBuilder uriBuilder = UriComponentsBuilder.fromUriString(targetLinkUri);
         lti13Service.buildLtiResponse(uriBuilder, response);
 
-        JSONObject json = new JSONObject();
-        json.put("targetLinkUri", uriBuilder.build().toUriString());
+        JsonObject json = new JsonObject();
+        json.addProperty("targetLinkUri", uriBuilder.build().toUriString());
 
         response.setContentType("application/json");
         response.setCharacterEncoding("UTF-8");

src/main/java/de/tum/in/www1/artemis/service/connectors/lti/Lti13Service.java

@@ -26,14 +26,15 @@
 import org.springframework.web.client.RestTemplate;
 import org.springframework.web.util.UriComponentsBuilder;
 
+import com.google.gson.JsonObject;
+
 import de.tum.in.www1.artemis.domain.*;
 import de.tum.in.www1.artemis.domain.lti.*;
 import de.tum.in.www1.artemis.domain.participation.StudentParticipation;
 import de.tum.in.www1.artemis.repository.*;
 import de.tum.in.www1.artemis.security.lti.Lti13TokenRetriever;
 import de.tum.in.www1.artemis.service.OnlineCourseConfigurationService;
 import de.tum.in.www1.artemis.web.rest.errors.BadRequestAlertException;
-import net.minidev.json.JSONObject;
 
 @Service
 @Profile("lti")
@@ -222,15 +223,15 @@ private String getScoresUrl(String lineItemUrl) {
     }
 
     private String getScoreBody(String userId, String comment, Double score) {
-        JSONObject requestBody = new JSONObject();
-        requestBody.put("userId", userId);
-        requestBody.put("timestamp", (new DateTime()).toString());
-        requestBody.put("activityProgress", "Submitted");
-        requestBody.put("gradingProgress", "FullyGraded");
-        requestBody.put("comment", comment);
-        requestBody.put("scoreGiven", score);
-        requestBody.put("scoreMaximum", 100D);
-        return requestBody.toJSONString();
+        JsonObject requestBody = new JsonObject();
+        requestBody.addProperty("userId", userId);
+        requestBody.addProperty("timestamp", (new DateTime()).toString());
+        requestBody.addProperty("activityProgress", "Submitted");
+        requestBody.addProperty("gradingProgress", "FullyGraded");
+        requestBody.addProperty("comment", comment);
+        requestBody.addProperty("scoreGiven", score);
+        requestBody.addProperty("scoreMaximum", 100D);
+        return requestBody.toString();
     }
 
     /**

src/test/java/de/tum/in/www1/artemis/ArchitectureTest.java

@@ -107,6 +107,19 @@ void testLogging() {
         GeneralCodingRules.NO_CLASSES_SHOULD_ACCESS_STANDARD_STREAMS.check(classes);
     }
 
+    @Test
+    void testJSONImplementations() {
+        ArchRule jsonObject = noClasses().should().dependOnClassesThat(have(simpleName("JsonObject").or(simpleName("JSONObject"))).and(not(resideInAPackage("com.google.gson"))));
+
+        ArchRule jsonArray = noClasses().should().dependOnClassesThat(have(simpleName("JsonArray").or(simpleName("JSONArray"))).and(not(resideInAPackage("com.google.gson"))));
+
+        ArchRule jsonParser = noClasses().should().dependOnClassesThat(have(simpleName("JsonParser").or(simpleName("JSONParser"))).and(not(resideInAPackage("com.google.gson"))));
+
+        jsonObject.check(allClasses);
+        jsonArray.check(allClasses);
+        jsonParser.check(allClasses);
+    }
+
     // Custom Predicates for JavaAnnotations since ArchUnit only defines them for classes
 
     private DescribedPredicate<? super JavaAnnotation<?>> simpleNameAnnotation(String name) {

src/test/java/de/tum/in/www1/artemis/ImprintResourceIntegrationTest.java

@@ -17,9 +17,10 @@
 import org.springframework.http.HttpStatus;
 import org.springframework.security.test.context.support.WithMockUser;
 
+import com.google.gson.JsonObject;
+
 import de.tum.in.www1.artemis.domain.Imprint;
 import de.tum.in.www1.artemis.domain.enumeration.Language;
-import net.minidev.json.JSONObject;
 
 class ImprintResourceIntegrationTest extends AbstractSpringIntegrationIndependentTest {
 
@@ -212,10 +213,10 @@ void testUpdateImprint_writesFile_ReturnsUpdatedFileContent() throws Exception {
     @Test
     @WithMockUser(username = TEST_PREFIX + "admin", roles = "ADMIN")
     void testUpdateImprint_unsupportedLanguageBadRequest() throws Exception {
-        JSONObject body = new JSONObject();
-        body.put("text", "test");
-        body.put("language", "FRENCH");
-        request.put("/api/admin/imprint", body, HttpStatus.BAD_REQUEST);
+        JsonObject body = new JsonObject();
+        body.addProperty("text", "test");
+        body.addProperty("language", "FRENCH");
+        request.put("/api/admin/imprint", body.toString(), HttpStatus.BAD_REQUEST);
     }
 
     @Test

src/test/java/de/tum/in/www1/artemis/PrivacyStatementResourceIntegrationTest.java

@@ -17,9 +17,10 @@
 import org.springframework.http.HttpStatus;
 import org.springframework.security.test.context.support.WithMockUser;
 
+import com.google.gson.JsonObject;
+
 import de.tum.in.www1.artemis.domain.PrivacyStatement;
 import de.tum.in.www1.artemis.domain.enumeration.Language;
-import net.minidev.json.JSONObject;
 
 class PrivacyStatementResourceIntegrationTest extends AbstractSpringIntegrationIndependentTest {
 
@@ -220,10 +221,10 @@ void testUpdatePrivacyStatement_writesFile_ReturnsUpdatedFileContent() throws Ex
     @Test
     @WithMockUser(username = TEST_PREFIX + "admin", roles = "ADMIN")
     void testUpdatePrivacyStatement_unsupportedLanguageBadRequest() throws Exception {
-        JSONObject body = new JSONObject();
-        body.put("text", "test");
-        body.put("language", "FRENCH");
-        request.put("/api/admin/privacy-statement", body, HttpStatus.BAD_REQUEST);
+        JsonObject body = new JsonObject();
+        body.addProperty("text", "test");
+        body.addProperty("language", "FRENCH");
+        request.put("/api/admin/privacy-statement", body.toString(), HttpStatus.BAD_REQUEST);
     }
 
     @Test

src/test/java/de/tum/in/www1/artemis/connectors/Lti13ServiceTest.java

@@ -25,9 +25,8 @@
 import org.springframework.web.client.RestTemplate;
 import org.springframework.web.util.UriComponentsBuilder;
 
-import com.nimbusds.jose.shaded.json.JSONObject;
-import com.nimbusds.jose.shaded.json.parser.JSONParser;
-import com.nimbusds.jose.shaded.json.parser.ParseException;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
 
 import de.tum.in.www1.artemis.domain.*;
 import de.tum.in.www1.artemis.domain.lti.LtiResourceLaunch;
@@ -118,8 +117,8 @@ void performLaunch_exerciseFound() {
         when(oidcIdToken.getClaim("sub")).thenReturn("1");
         when(oidcIdToken.getClaim("iss")).thenReturn("http://otherDomain.com");
         when(oidcIdToken.getClaim(Claims.LTI_DEPLOYMENT_ID)).thenReturn("1");
-        JSONObject jsonObject = new JSONObject();
-        jsonObject.put("id", "resourceLinkUrl");
+        JsonObject jsonObject = new JsonObject();
+        jsonObject.addProperty("id", "resourceLinkUrl");
         when(oidcIdToken.getClaim(Claims.RESOURCE_LINK)).thenReturn(jsonObject);
         when(oidcIdToken.getClaim(Claims.TARGET_LINK_URI)).thenReturn("https://some-artemis-domain.org/courses/" + courseId + "/exercises/" + exerciseId);
 
@@ -420,7 +419,7 @@ void onNewResultTokenFails() {
     }
 
     @Test
-    void onNewResult() throws ParseException {
+    void onNewResult() {
         Result result = new Result();
         double scoreGiven = 60D;
         result.setScore(scoreGiven);
@@ -464,16 +463,15 @@ void onNewResult() throws ParseException {
         assertThat(authHeaders).as("Score publish request must contain an Authorization header").isNotNull();
         assertThat(authHeaders).as("Score publish request must contain the corresponding Authorization Bearer token").contains("Bearer " + accessToken);
 
-        JSONParser jsonParser = new JSONParser(JSONParser.MODE_JSON_SIMPLE);
-        JSONObject body = (JSONObject) jsonParser.parse(httpEntity.getBody());
-        assertThat(body.get("userId")).as("Invalid parameter in score publish request: userId").isEqualTo(launch.getSub());
-        assertThat(body.get("timestamp")).as("Parameter missing in score publish request: timestamp").isNotNull();
-        assertThat(body.get("activityProgress")).as("Parameter missing in score publish request: activityProgress").isNotNull();
-        assertThat(body.get("gradingProgress")).as("Parameter missing in score publish request: gradingProgress").isNotNull();
+        JsonObject body = JsonParser.parseString(httpEntity.getBody()).getAsJsonObject();
+        assertThat(body.get("userId").getAsString()).as("Invalid parameter in score publish request: userId").isEqualTo(launch.getSub());
+        assertThat(body.get("timestamp").getAsString()).as("Parameter missing in score publish request: timestamp").isNotNull();
+        assertThat(body.get("activityProgress").getAsString()).as("Parameter missing in score publish request: activityProgress").isNotNull();
+        assertThat(body.get("gradingProgress").getAsString()).as("Parameter missing in score publish request: gradingProgress").isNotNull();
 
-        assertThat(body.get("comment")).as("Invalid parameter in score publish request: comment").isEqualTo("Good job. Not so good");
-        assertThat(body.get("scoreGiven")).as("Invalid parameter in score publish request: scoreGiven").isEqualTo(scoreGiven);
-        assertThat(body.get("scoreMaximum")).as("Invalid parameter in score publish request: scoreMaximum").isEqualTo(100d);
+        assertThat(body.get("comment").getAsString()).as("Invalid parameter in score publish request: comment").isEqualTo("Good job. Not so good");
+        assertThat(body.get("scoreGiven").getAsDouble()).as("Invalid parameter in score publish request: scoreGiven").isEqualTo(scoreGiven);
+        assertThat(body.get("scoreMaximum").getAsDouble()).as("Invalid parameter in score publish request: scoreMaximum").isEqualTo(100d);
 
         assertThat(launch.getScoreLineItemUrl() + "/scores").as("Score publish request was sent to a wrong URI").isEqualTo(urlCapture.getValue());
     }

src/test/java/de/tum/in/www1/artemis/exercise/programmingexercise/GitlabServiceTest.java

@@ -9,8 +9,6 @@
 import java.net.URL;
 
 import org.gitlab4j.api.GitLabApiException;
-import org.json.simple.parser.JSONParser;
-import org.json.simple.parser.ParseException;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -22,6 +20,7 @@
 import org.springframework.security.test.context.support.WithMockUser;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
 
 import de.tum.in.www1.artemis.AbstractSpringIntegrationJenkinsGitlabTest;
 import de.tum.in.www1.artemis.domain.Commit;
@@ -118,9 +117,9 @@ void testGetOrRetrieveDefaultBranch() throws GitLabApiException {
     }
 
     @Test
-    void testGetLastCommitDetails() throws ParseException {
+    void testGetLastCommitDetails() throws JsonProcessingException {
         String latestCommitHash = "11028e4104243d8cbae9175f2bc938cb8c2d7924";
-        Object body = new JSONParser().parse(GITLAB_PUSH_EVENT_REQUEST);
+        Object body = new ObjectMapper().readValue(GITLAB_PUSH_EVENT_REQUEST, Object.class);
         Commit commit = versionControlService.getLastCommitDetails(body);
         assertThat(commit.getCommitHash()).isEqualTo(latestCommitHash);
         assertThat(commit.getBranch()).isNotNull();
@@ -130,9 +129,9 @@ void testGetLastCommitDetails() throws ParseException {
     }
 
     @Test
-    void testGetLastCommitDetailsWrongCommitOrder() throws ParseException {
+    void testGetLastCommitDetailsWrongCommitOrder() throws JsonProcessingException {
         String latestCommitHash = "11028e4104243d8cbae9175f2bc938cb8c2d7924";
-        Object body = new JSONParser().parse(GITLAB_PUSH_EVENT_REQUEST_WRONG_COMMIT_ORDER);
+        Object body = new ObjectMapper().readValue(GITLAB_PUSH_EVENT_REQUEST_WRONG_COMMIT_ORDER, Object.class);
         Commit commit = versionControlService.getLastCommitDetails(body);
         assertThat(commit.getCommitHash()).isEqualTo(latestCommitHash);
         assertThat(commit.getBranch()).isNotNull();
@@ -142,9 +141,9 @@ void testGetLastCommitDetailsWrongCommitOrder() throws ParseException {
     }
 
     @Test
-    void testGetLastCommitDetailsWithoutCommits() throws ParseException {
+    void testGetLastCommitDetailsWithoutCommits() throws JsonProcessingException {
         String latestCommitHash = "11028e4104243d8cbae9175f2bc938cb8c2d7924";
-        Object body = new JSONParser().parse(GITLAB_PUSH_EVENT_REQUEST_WITHOUT_COMMIT);
+        Object body = new ObjectMapper().readValue(GITLAB_PUSH_EVENT_REQUEST_WITHOUT_COMMIT, Object.class);
         Commit commit = versionControlService.getLastCommitDetails(body);
         assertThat(commit.getCommitHash()).isEqualTo(latestCommitHash);
         assertThat(commit.getBranch()).isNull();

src/test/java/de/tum/in/www1/artemis/exercise/programmingexercise/ProgrammingExerciseBitbucketBambooIntegrationTest.java

@@ -13,7 +13,6 @@
 import java.util.Arrays;
 import java.util.stream.Stream;
 
-import org.json.simple.parser.JSONParser;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -24,6 +23,8 @@
 import org.springframework.http.HttpStatus;
 import org.springframework.security.test.context.support.WithMockUser;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+
 import de.tum.in.www1.artemis.AbstractSpringIntegrationBambooBitbucketJiraTest;
 import de.tum.in.www1.artemis.domain.enumeration.ExerciseMode;
 import de.tum.in.www1.artemis.domain.enumeration.ProgrammingLanguage;
@@ -218,7 +219,7 @@ void resumeProgrammingExercise_doesNotExist(ExerciseMode exerciseMode) throws Ex
     void resumeProgrammingExerciseByPushingIntoRepo_correctInitializationState(ExerciseMode exerciseMode) throws Exception {
         final String requestAsArtemisUser = BITBUCKET_PUSH_EVENT_REQUEST.replace("\"name\": \"admin\"", "\"name\": \"Artemis\"").replace("\"displayName\": \"Admin\"",
                 "\"displayName\": \"Artemis\"");
-        Object body = new JSONParser().parse(requestAsArtemisUser);
+        Object body = new ObjectMapper().readValue(requestAsArtemisUser, Object.class);
         programmingExerciseTestService.resumeProgrammingExerciseByPushingIntoRepo_correctInitializationState(exerciseMode, body);
     }
 

src/test/java/de/tum/in/www1/artemis/exercise/programmingexercise/ProgrammingExerciseGitlabJenkinsIntegrationTest.java

@@ -13,7 +13,6 @@
 import java.util.Arrays;
 import java.util.stream.Stream;
 
-import org.json.simple.parser.JSONParser;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -24,6 +23,8 @@
 import org.springframework.http.HttpStatus;
 import org.springframework.security.test.context.support.WithMockUser;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+
 import de.tum.in.www1.artemis.AbstractSpringIntegrationJenkinsGitlabTest;
 import de.tum.in.www1.artemis.domain.enumeration.ExerciseMode;
 import de.tum.in.www1.artemis.domain.enumeration.ProgrammingLanguage;
@@ -278,7 +279,7 @@ void resumeProgrammingExercise_doesNotExist(ExerciseMode exerciseMode) throws Ex
     @EnumSource(ExerciseMode.class)
     @WithMockUser(username = TEST_PREFIX + studentLogin, roles = "USER")
     void resumeProgrammingExerciseByPushingIntoRepo_correctInitializationState(ExerciseMode exerciseMode) throws Exception {
-        Object body = new JSONParser().parse(GITLAB_PUSH_EVENT_REQUEST);
+        Object body = new ObjectMapper().readValue(GITLAB_PUSH_EVENT_REQUEST, Object.class);
         programmingExerciseTestService.resumeProgrammingExerciseByPushingIntoRepo_correctInitializationState(exerciseMode, body);
     }