policy-agent/src/test/java/org/oransc/policyagent/ApplicationTest.java

   1 /*-
   2  * ========================LICENSE_START=================================
   3  * O-RAN-SC
   4  * %%
   5  * Copyright (C) 2019 Nordix Foundation
   6  * %%
   7  * Licensed under the Apache License, Version 2.0 (the "License");
   8  * you may not use this file except in compliance with the License.
   9  * You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  * ========================LICENSE_END===================================
  19  */
  20
  21 package org.oransc.policyagent;
  22
  23 import static org.assertj.core.api.Assertions.assertThat;
  24 import static org.awaitility.Awaitility.await;
  25 import static org.junit.jupiter.api.Assertions.assertTrue;
  26
  27 import com.google.gson.Gson;
  28 import com.google.gson.GsonBuilder;
  29 import com.google.gson.JsonArray;
  30 import com.google.gson.JsonElement;
  31 import com.google.gson.JsonParser;
  32
  33 import java.time.Duration;
  34 import java.time.Instant;
  35 import java.util.ArrayList;
  36 import java.util.List;
  37 import java.util.concurrent.atomic.AtomicInteger;
  38
  39 import org.junit.jupiter.api.AfterEach;
  40 import org.junit.jupiter.api.BeforeEach;
  41 import org.junit.jupiter.api.Test;
  42 import org.junit.jupiter.api.extension.ExtendWith;
  43 import org.oransc.policyagent.clients.AsyncRestClient;
  44 import org.oransc.policyagent.configuration.ApplicationConfig;
  45 import org.oransc.policyagent.configuration.ImmutableRicConfig;
  46 import org.oransc.policyagent.configuration.RicConfig;
  47 import org.oransc.policyagent.controllers.PolicyInfo;
  48 import org.oransc.policyagent.controllers.ServiceRegistrationInfo;
  49 import org.oransc.policyagent.controllers.ServiceStatus;
  50 import org.oransc.policyagent.exceptions.ServiceException;
  51 import org.oransc.policyagent.repository.ImmutablePolicy;
  52 import org.oransc.policyagent.repository.ImmutablePolicyType;
  53 import org.oransc.policyagent.repository.Lock.LockType;
  54 import org.oransc.policyagent.repository.Policies;
  55 import org.oransc.policyagent.repository.Policy;
  56 import org.oransc.policyagent.repository.PolicyType;
  57 import org.oransc.policyagent.repository.PolicyTypes;
  58 import org.oransc.policyagent.repository.Ric;
  59 import org.oransc.policyagent.repository.Ric.RicState;
  60 import org.oransc.policyagent.repository.Rics;
  61 import org.oransc.policyagent.repository.Services;
  62 import org.oransc.policyagent.tasks.RepositorySupervision;
  63 import org.oransc.policyagent.utils.MockA1Client;
  64 import org.oransc.policyagent.utils.MockA1ClientFactory;
  65 import org.springframework.beans.factory.annotation.Autowired;
  66 import org.springframework.boot.test.context.SpringBootTest;
  67 import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
  68 import org.springframework.boot.test.context.TestConfiguration;
  69 import org.springframework.boot.web.server.LocalServerPort;
  70 import org.springframework.context.ApplicationContext;
  71 import org.springframework.context.annotation.Bean;
  72 import org.springframework.http.HttpEntity;
  73 import org.springframework.http.HttpHeaders;
  74 import org.springframework.http.HttpStatus;
  75 import org.springframework.http.MediaType;
  76 import org.springframework.http.ResponseEntity;
  77 import org.springframework.test.context.junit.jupiter.SpringExtension;
  78 import org.springframework.web.client.RestTemplate;
  79 import org.springframework.web.reactive.function.client.WebClientResponseException;
  80
  81 import reactor.core.publisher.Mono;
  82 import reactor.test.StepVerifier;
  83
  84 @ExtendWith(SpringExtension.class)
  85 @SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
  86 public class ApplicationTest {
  87     @Autowired
  88     ApplicationContext context;
  89
  90     @Autowired
  91     private Rics rics;
  92
  93     @Autowired
  94     private Policies policies;
  95
  96     @Autowired
  97     private PolicyTypes policyTypes;
  98
  99     @Autowired
 100     MockA1ClientFactory a1ClientFactory;
 101
 102     @Autowired
 103     RepositorySupervision supervision;
 104
 105     @Autowired
 106     Services services;
 107
 108     private static Gson gson = new GsonBuilder() //
 109         .serializeNulls() //
 110         .create(); //
 111
 112     public static class MockApplicationConfig extends ApplicationConfig {
 113         @Override
 114         public String getLocalConfigurationFilePath() {
 115             return ""; // No config file loaded for the test
 116         }
 117     }
 118
 119     /**
 120      * Overrides the BeanFactory.
 121      */
 122     @TestConfiguration
 123     static class TestBeanFactory {
 124         private final PolicyTypes policyTypes = new PolicyTypes();
 125
 126         @Bean
 127         public ApplicationConfig getApplicationConfig() {
 128             return new MockApplicationConfig();
 129         }
 130
 131         @Bean
 132         MockA1ClientFactory getA1ClientFactory() {
 133             return new MockA1ClientFactory(this.policyTypes);
 134         }
 135
 136         @Bean
 137         public PolicyTypes getPolicyTypes() {
 138             return this.policyTypes;
 139         }
 140     }
 141
 142     @LocalServerPort
 143     private int port;
 144
 145     @BeforeEach
 146     public void reset() {
 147         rics.clear();
 148         policies.clear();
 149         policyTypes.clear();
 150         services.clear();
 151     }
 152
 153     @AfterEach
 154     public void verifyNoRicLocks() {
 155         for (Ric ric : this.rics.getRics()) {
 156             ric.getLock().lockBlocking(LockType.EXCLUSIVE);
 157             ric.getLock().unlockBlocking();
 158             assertThat(ric.getLock().getLockCounter()).isEqualTo(0);
 159             assertThat(ric.getState()).isEqualTo(Ric.RicState.IDLE);
 160         }
 161     }
 162
 163     @Test
 164     public void testGetRics() throws Exception {
 165         addRic("kista_1");
 166         this.addPolicyType("type1", "kista_1");
 167         String url = "/rics?policyType=type1";
 168         String rsp = restClient().get(url).block();
 169         assertThat(rsp).contains("kista_1");
 170
 171         // Non existing policy type
 172         url = "/rics?policyType=XXXX";
 173         testErrorCode(restClient().get(url), HttpStatus.NOT_FOUND);
 174     }
 175
 176     @Test
 177     public void testRecovery() throws Exception {
 178         addRic("ric").setState(Ric.RicState.UNDEFINED);
 179         String ricName = "ric";
 180         Policy policy2 = addPolicy("policyId2", "typeName", "service", ricName);
 181
 182         getA1Client(ricName).putPolicy(policy2); // put it in the RIC
 183         policies.remove(policy2); // Remove it from the repo -> should be deleted in the RIC
 184
 185         String policyId = "policyId";
 186         Policy policy = addPolicy(policyId, "typeName", "service", ricName); // This should be created in the RIC
 187         supervision.checkAllRics(); // The created policy should be put in the RIC
 188         await().untilAsserted(() -> RicState.SYNCHRONIZING.equals(rics.getRic(ricName).getState()));
 189         await().untilAsserted(() -> RicState.IDLE.equals(rics.getRic(ricName).getState()));
 190
 191         Policies ricPolicies = getA1Client(ricName).getPolicies();
 192         assertThat(ricPolicies.size()).isEqualTo(1);
 193         Policy ricPolicy = ricPolicies.get(policyId);
 194         assertThat(ricPolicy.json()).isEqualTo(policy.json());
 195     }
 196
 197     @Test
 198     public void testGetRicForManagedElement_thenReturnCorrectRic() throws Exception {
 199         String ricName = "ric1";
 200         String managedElementId = "kista_1";
 201         addRic(ricName, managedElementId);
 202
 203         String url = "/ric?managedElementId=" + managedElementId;
 204         String rsp = restClient().get(url).block();
 205         assertThat(rsp).isEqualTo(ricName);
 206
 207         // test GET RIC for ManagedElement that does not exist
 208         url = "/ric?managedElementId=" + "junk";
 209         testErrorCode(restClient().get(url), HttpStatus.NOT_FOUND);
 210     }
 211
 212     private String putPolicyUrl(String serviceName, String ricName, String policyTypeName, String policyInstanceId) {
 213         String url = "/policy?type=" + policyTypeName + "&instance=" + policyInstanceId + "&ric=" + ricName
 214             + "&service=" + serviceName;
 215         return url;
 216     }
 217
 218     @Test
 219     public void testPutPolicy() throws Exception {
 220         String serviceName = "service1";
 221         String ricName = "ric1";
 222         String policyTypeName = "type1";
 223         String policyInstanceId = "instance1";
 224
 225         putService(serviceName);
 226         addPolicyType(policyTypeName, ricName);
 227
 228         String url = putPolicyUrl(serviceName, ricName, policyTypeName, policyInstanceId);
 229         final String policyBody = jsonString();
 230         this.rics.getRic(ricName).setState(Ric.RicState.IDLE);
 231
 232         restClient().put(url, policyBody).block();
 233
 234         Policy policy = policies.getPolicy(policyInstanceId);
 235         assertThat(policy).isNotNull();
 236         assertThat(policy.id()).isEqualTo(policyInstanceId);
 237         assertThat(policy.ownerServiceName()).isEqualTo(serviceName);
 238         assertThat(policy.ric().name()).isEqualTo("ric1");
 239
 240         url = "/policies";
 241         String rsp = restClient().get(url).block();
 242         assertThat(rsp.contains(policyInstanceId)).isTrue();
 243
 244         // Test of error codes
 245         url = putPolicyUrl(serviceName, ricName + "XX", policyTypeName, policyInstanceId);
 246         testErrorCode(restClient().put(url, policyBody), HttpStatus.NOT_FOUND);
 247
 248         url = putPolicyUrl(serviceName, ricName, policyTypeName + "XX", policyInstanceId);
 249         testErrorCode(restClient().put(url, policyBody), HttpStatus.NOT_FOUND);
 250
 251         url = putPolicyUrl(serviceName, ricName, policyTypeName, policyInstanceId);
 252         this.rics.getRic(ricName).setState(Ric.RicState.SYNCHRONIZING);
 253         testErrorCode(restClient().put(url, policyBody), HttpStatus.LOCKED);
 254         this.rics.getRic(ricName).setState(Ric.RicState.IDLE);
 255     }
 256
 257     @Test
 258     public void testRefuseToUpdatePolicy() throws Exception {
 259         // Test that only the json can be changed for a already created policy
 260         // In this case service is attempted to be changed
 261         this.addRic("ric1");
 262         this.addRic("ricXXX");
 263         this.addPolicy("instance1", "type1", "service1", "ric1");
 264
 265         // Try change ric1 -> ricXXX
 266         String urlWrongRic = putPolicyUrl("service1", "ricXXX", "type1", "instance1");
 267         testErrorCode(restClient().put(urlWrongRic, jsonString()), HttpStatus.METHOD_NOT_ALLOWED);
 268     }
 269
 270     @Test
 271     public void testGetPolicy() throws Exception {
 272         String url = "/policy?instance=id";
 273         Policy policy = addPolicy("id", "typeName", "service1", "ric1");
 274         {
 275             String rsp = restClient().get(url).block();
 276             assertThat(rsp).isEqualTo(policy.json());
 277         }
 278         {
 279             policies.remove(policy);
 280             testErrorCode(restClient().get(url), HttpStatus.NOT_FOUND);
 281         }
 282     }
 283
 284     @Test
 285     public void testDeletePolicy() throws Exception {
 286         addPolicy("id", "typeName", "service1", "ric1");
 287         assertThat(policies.size()).isEqualTo(1);
 288
 289         String url = "/policy?instance=id";
 290         ResponseEntity<String> entity = restClient().deleteForEntity(url).block();
 291
 292         assertThat(entity.getStatusCode()).isEqualTo(HttpStatus.NO_CONTENT);
 293         assertThat(policies.size()).isEqualTo(0);
 294
 295         // Delete a non existing policy
 296         testErrorCode(restClient().get(url), HttpStatus.NOT_FOUND);
 297     }
 298
 299     @Test
 300     public void testGetPolicySchemas() throws Exception {
 301         addPolicyType("type1", "ric1");
 302         addPolicyType("type2", "ric2");
 303
 304         String url = "/policy_schemas";
 305         String rsp = this.restClient().get(url).block();
 306         assertThat(rsp).contains("type1");
 307         assertThat(rsp).contains("[{\"title\":\"type2\"}");
 308
 309         List<String> info = parseSchemas(rsp);
 310         assertThat(info.size()).isEqualTo(2);
 311
 312         url = "/policy_schemas?ric=ric1";
 313         rsp = restClient().get(url).block();
 314         assertThat(rsp).contains("type1");
 315         info = parseSchemas(rsp);
 316         assertThat(info.size()).isEqualTo(1);
 317
 318         // Get schema for non existing RIC
 319         url = "/policy_schemas?ric=ric1XXX";
 320         testErrorCode(restClient().get(url), HttpStatus.NOT_FOUND);
 321     }
 322
 323     @Test
 324     public void testGetPolicySchema() throws Exception {
 325         addPolicyType("type1", "ric1");
 326         addPolicyType("type2", "ric2");
 327
 328         String url = "/policy_schema?id=type1";
 329         String rsp = restClient().get(url).block();
 330         System.out.println(rsp);
 331         assertThat(rsp).contains("type1");
 332         assertThat(rsp).contains("title");
 333
 334         // Get non existing schema
 335         url = "/policy_schema?id=type1XX";
 336         testErrorCode(restClient().get(url), HttpStatus.NOT_FOUND);
 337     }
 338
 339     @Test
 340     public void testGetPolicyTypes() throws Exception {
 341         addPolicyType("type1", "ric1");
 342         addPolicyType("type2", "ric2");
 343
 344         String url = "/policy_types";
 345         String rsp = restClient().get(url).block();
 346         assertThat(rsp).isEqualTo("[\"type2\",\"type1\"]");
 347
 348         url = "/policy_types?ric=ric1";
 349         rsp = restClient().get(url).block();
 350         assertThat(rsp).isEqualTo("[\"type1\"]");
 351
 352         // Get policy types for non existing RIC
 353         url = "/policy_types?ric=ric1XXX";
 354         testErrorCode(restClient().get(url), HttpStatus.NOT_FOUND);
 355     }
 356
 357     @Test
 358     public void testGetPolicies() throws Exception {
 359         reset();
 360         addPolicy("id1", "type1", "service1");
 361
 362         String url = "/policies";
 363         String rsp = restClient().get(url).block();
 364         System.out.println(rsp);
 365         List<PolicyInfo> info = parseList(rsp, PolicyInfo.class);
 366         assertThat(info).size().isEqualTo(1);
 367         PolicyInfo policyInfo = info.get(0);
 368         assert (policyInfo.validate());
 369         assertThat(policyInfo.id).isEqualTo("id1");
 370         assertThat(policyInfo.type).isEqualTo("type1");
 371         assertThat(policyInfo.service).isEqualTo("service1");
 372     }
 373
 374     @Test
 375     public void testGetPoliciesFilter() throws Exception {
 376         addPolicy("id1", "type1", "service1");
 377         addPolicy("id2", "type1", "service2");
 378         addPolicy("id3", "type2", "service1");
 379
 380         String url = "/policies?type=type1";
 381         String rsp = restClient().get(url).block();
 382         System.out.println(rsp);
 383         assertThat(rsp).contains("id1");
 384         assertThat(rsp).contains("id2");
 385         assertThat(rsp.contains("id3")).isFalse();
 386
 387         url = "/policies?type=type1&service=service2";
 388         rsp = restClient().get(url).block();
 389         System.out.println(rsp);
 390         assertThat(rsp.contains("id1")).isFalse();
 391         assertThat(rsp).contains("id2");
 392         assertThat(rsp.contains("id3")).isFalse();
 393
 394         // Test get policies for non existing type
 395         url = "/policies?type=type1XXX";
 396         testErrorCode(restClient().get(url), HttpStatus.NOT_FOUND);
 397
 398         // Test get policies for non existing RIC
 399         url = "/policies?ric=XXX";
 400         testErrorCode(restClient().get(url), HttpStatus.NOT_FOUND);
 401     }
 402
 403     @Test
 404     public void testPutAndGetService() throws Exception {
 405         // PUT
 406         putService("name");
 407
 408         // GET one service
 409         String url = "/services?name=name";
 410         String rsp = restClient().get(url).block();
 411         List<ServiceStatus> info = parseList(rsp, ServiceStatus.class);
 412         assertThat(info.size()).isEqualTo(1);
 413         ServiceStatus status = info.iterator().next();
 414         assertThat(status.keepAliveIntervalSeconds).isEqualTo(1);
 415         assertThat(status.serviceName).isEqualTo("name");
 416
 417         // GET (all)
 418         url = "/services";
 419         rsp = restClient().get(url).block();
 420         assertThat(rsp.contains("name")).isTrue();
 421         System.out.println(rsp);
 422
 423         // Keep alive
 424         url = "/services/keepalive?name=name";
 425         ResponseEntity<String> entity = restClient().postForEntity(url, null).block();
 426         assertThat(entity.getStatusCode()).isEqualTo(HttpStatus.OK);
 427
 428         // DELETE service
 429         assertThat(services.size()).isEqualTo(1);
 430         url = "/services?name=name";
 431         restClient().delete(url).block();
 432         assertThat(services.size()).isEqualTo(0);
 433
 434         // Keep alive, no registerred service
 435         testErrorCode(restClient().post("/services/keepalive?name=name", ""), HttpStatus.NOT_FOUND);
 436
 437         // PUT servive with crap payload
 438         testErrorCode(restClient().put("/service", "junk"), HttpStatus.BAD_REQUEST);
 439
 440         // GET non existing servive
 441         testErrorCode(restClient().get("/services?name=XXX"), HttpStatus.NOT_FOUND);
 442     }
 443
 444     @Test
 445     public void testGetPolicyStatus() throws Exception {
 446         addPolicy("id", "typeName", "service1", "ric1");
 447         assertThat(policies.size()).isEqualTo(1);
 448
 449         String url = "/policy_status?instance=id";
 450         String rsp = restClient().get(url).block();
 451         assertThat(rsp.equals("OK")).isTrue();
 452
 453         // GET non existing policy status
 454         url = "/policy_status?instance=XXX";
 455         testErrorCode(restClient().get(url), HttpStatus.NOT_FOUND);
 456     }
 457
 458     private Policy addPolicy(String id, String typeName, String service, String ric) throws ServiceException {
 459         addRic(ric);
 460         Policy p = ImmutablePolicy.builder().id(id) //
 461             .json(jsonString()) //
 462             .ownerServiceName(service) //
 463             .ric(rics.getRic(ric)) //
 464             .type(addPolicyType(typeName, ric)) //
 465             .lastModified("lastModified").build();
 466         policies.put(p);
 467         return p;
 468     }
 469
 470     private Policy addPolicy(String id, String typeName, String service) throws ServiceException {
 471         return addPolicy(id, typeName, service, "ric");
 472     }
 473
 474     private String createServiceJson(String name) {
 475         ServiceRegistrationInfo service = new ServiceRegistrationInfo(name, 1, "callbackUrl");
 476
 477         String json = gson.toJson(service);
 478         return json;
 479     }
 480
 481     private void putService(String name) {
 482         String url = "/service";
 483         restClient().put(url, createServiceJson(name)).block();
 484     }
 485
 486     private String baseUrl() {
 487         return "http://localhost:" + port;
 488     }
 489
 490     private String jsonString() {
 491         return "{\n  \"servingCellNrcgi\": \"1\"\n }";
 492     }
 493
 494     private static class ConcurrencyTestRunnable implements Runnable {
 495         private final RestTemplate restTemplate = new RestTemplate();
 496         private final String baseUrl;
 497         static AtomicInteger nextCount = new AtomicInteger(0);
 498         private final int count;
 499         private final RepositorySupervision supervision;
 500
 501         ConcurrencyTestRunnable(String baseUrl, RepositorySupervision supervision) {
 502             this.baseUrl = baseUrl;
 503             this.count = nextCount.incrementAndGet();
 504             this.supervision = supervision;
 505         }
 506
 507         @Override
 508         public void run() {
 509             for (int i = 0; i < 100; ++i) {
 510                 if (i % 10 == 0) {
 511                     this.supervision.checkAllRics();
 512                 }
 513                 String name = "policy:" + count + ":" + i;
 514                 putPolicy(name);
 515                 deletePolicy(name);
 516             }
 517         }
 518
 519         private void putPolicy(String name) {
 520             String putUrl = baseUrl + "/policy?type=type1&instance=" + name + "&ric=ric1&service=service1";
 521             restTemplate.put(putUrl, createJsonHttpEntity("{}"));
 522         }
 523
 524         private void deletePolicy(String name) {
 525             String deleteUrl = baseUrl + "/policy?instance=" + name;
 526             restTemplate.delete(deleteUrl);
 527         }
 528     }
 529
 530     @Test
 531     public void testConcurrency() throws Exception {
 532         final Instant startTime = Instant.now();
 533         List<Thread> threads = new ArrayList<>();
 534         addRic("ric1");
 535         addPolicyType("type1", "ric1");
 536
 537         for (int i = 0; i < 100; ++i) {
 538             Thread t = new Thread(new ConcurrencyTestRunnable(baseUrl(), this.supervision), "TestThread_" + i);
 539             t.start();
 540             threads.add(t);
 541         }
 542         for (Thread t : threads) {
 543             t.join();
 544         }
 545         assertThat(policies.size()).isEqualTo(0);
 546         System.out.println("Concurrency test took " + Duration.between(startTime, Instant.now()));
 547     }
 548
 549     private AsyncRestClient restClient() {
 550         return new AsyncRestClient(baseUrl());
 551     }
 552
 553     private void testErrorCode(Mono<?> request, HttpStatus expStatus) {
 554         StepVerifier.create(request) //
 555             .expectSubscription() //
 556             .expectErrorMatches(t -> checkWebClientError(t, expStatus)) //
 557             .verify();
 558     }
 559
 560     private boolean checkWebClientError(Throwable t, HttpStatus expStatus) {
 561         assertTrue(t instanceof WebClientResponseException);
 562         WebClientResponseException e = (WebClientResponseException) t;
 563         assertThat(e.getStatusCode()).isEqualTo(expStatus);
 564         return true;
 565     }
 566
 567     private MockA1Client getA1Client(String ricName) throws ServiceException {
 568         return a1ClientFactory.getOrCreateA1Client(ricName);
 569     }
 570
 571     private PolicyType addPolicyType(String policyTypeName, String ricName) {
 572         PolicyType type = ImmutablePolicyType.builder() //
 573             .name(policyTypeName) //
 574             .schema("{\"title\":\"" + policyTypeName + "\"}") //
 575             .build();
 576
 577         policyTypes.put(type);
 578         addRic(ricName).addSupportedPolicyType(type);
 579         return type;
 580     }
 581
 582     private Ric addRic(String ricName) {
 583         return addRic(ricName, null);
 584     }
 585
 586     private Ric addRic(String ricName, String managedElement) {
 587         if (rics.get(ricName) != null) {
 588             return rics.get(ricName);
 589         }
 590         List<String> mes = new ArrayList<>();
 591         if (managedElement != null) {
 592             mes.add(managedElement);
 593         }
 594         RicConfig conf = ImmutableRicConfig.builder() //
 595             .name(ricName) //
 596             .baseUrl(ricName) //
 597             .managedElementIds(mes) //
 598             .build();
 599         Ric ric = new Ric(conf);
 600         ric.setState(Ric.RicState.IDLE);
 601         this.rics.put(ric);
 602         return ric;
 603     }
 604
 605     private static HttpEntity<String> createJsonHttpEntity(String content) {
 606         HttpHeaders headers = new HttpHeaders();
 607         headers.setContentType(MediaType.APPLICATION_JSON);
 608         return new HttpEntity<String>(content, headers);
 609     }
 610
 611     private static <T> List<T> parseList(String jsonString, Class<T> clazz) {
 612         List<T> result = new ArrayList<>();
 613         JsonArray jsonArr = JsonParser.parseString(jsonString).getAsJsonArray();
 614         for (JsonElement jsonElement : jsonArr) {
 615             T o = gson.fromJson(jsonElement.toString(), clazz);
 616             result.add(o);
 617         }
 618         return result;
 619     }
 620
 621     private static List<String> parseSchemas(String jsonString) {
 622         JsonArray arrayOfSchema = JsonParser.parseString(jsonString).getAsJsonArray();
 623         List<String> result = new ArrayList<>();
 624         for (JsonElement schemaObject : arrayOfSchema) {
 625             result.add(schemaObject.toString());
 626         }
 627         return result;
 628     }
 629 }