gerrit.onap Code Review - ccsdk/oran.git/blob

   1 /*-
   2  * ========================LICENSE_START=================================
   3  * ONAP : ccsdk oran
   4  * ======================================================================
   5  * Copyright (C) 2019-2020 Nordix Foundation. All rights reserved.
   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.onap.ccsdk.oran.a1policymanagementservice.controllers.v2;
  22
  23 import com.google.gson.Gson;
  24 import com.google.gson.GsonBuilder;
  25
  26 import io.swagger.v3.oas.annotations.Operation;
  27 import io.swagger.v3.oas.annotations.Parameter;
  28 import io.swagger.v3.oas.annotations.media.Content;
  29 import io.swagger.v3.oas.annotations.media.Schema;
  30 import io.swagger.v3.oas.annotations.responses.ApiResponse;
  31 import io.swagger.v3.oas.annotations.responses.ApiResponses;
  32 import io.swagger.v3.oas.annotations.tags.Tag;
  33
  34 import java.lang.invoke.MethodHandles;
  35 import java.time.Instant;
  36 import java.util.ArrayList;
  37 import java.util.Collection;
  38 import java.util.List;
  39
  40 import lombok.Getter;
  41
  42 import org.onap.ccsdk.oran.a1policymanagementservice.clients.A1ClientFactory;
  43 import org.onap.ccsdk.oran.a1policymanagementservice.controllers.VoidResponse;
  44 import org.onap.ccsdk.oran.a1policymanagementservice.exceptions.EntityNotFoundException;
  45 import org.onap.ccsdk.oran.a1policymanagementservice.exceptions.ServiceException;
  46 import org.onap.ccsdk.oran.a1policymanagementservice.repository.Lock.LockType;
  47 import org.onap.ccsdk.oran.a1policymanagementservice.repository.Policies;
  48 import org.onap.ccsdk.oran.a1policymanagementservice.repository.Policy;
  49 import org.onap.ccsdk.oran.a1policymanagementservice.repository.PolicyType;
  50 import org.onap.ccsdk.oran.a1policymanagementservice.repository.PolicyTypes;
  51 import org.onap.ccsdk.oran.a1policymanagementservice.repository.Ric;
  52 import org.onap.ccsdk.oran.a1policymanagementservice.repository.Rics;
  53 import org.onap.ccsdk.oran.a1policymanagementservice.repository.Service;
  54 import org.onap.ccsdk.oran.a1policymanagementservice.repository.Services;
  55 import org.slf4j.Logger;
  56 import org.slf4j.LoggerFactory;
  57 import org.springframework.beans.factory.annotation.Autowired;
  58 import org.springframework.http.HttpStatus;
  59 import org.springframework.http.MediaType;
  60 import org.springframework.http.ResponseEntity;
  61 import org.springframework.web.bind.annotation.DeleteMapping;
  62 import org.springframework.web.bind.annotation.GetMapping;
  63 import org.springframework.web.bind.annotation.PathVariable;
  64 import org.springframework.web.bind.annotation.PutMapping;
  65 import org.springframework.web.bind.annotation.RequestBody;
  66 import org.springframework.web.bind.annotation.RequestParam;
  67 import org.springframework.web.bind.annotation.RestController;
  68 import org.springframework.web.reactive.function.client.WebClientResponseException;
  69 import reactor.core.publisher.Mono;
  70
  71 @RestController("PolicyControllerV2")
  72 @Tag(name = PolicyController.API_NAME)
  73 public class PolicyController {
  74
  75     public static final String API_NAME = "A1 Policy Management";
  76     public static final String API_DESCRIPTION = "";
  77
  78     public static class RejectionException extends Exception {
  79         private static final long serialVersionUID = 1L;
  80
  81         @Getter
  82         private final HttpStatus status;
  83
  84         public RejectionException(String message, HttpStatus status) {
  85             super(message);
  86             this.status = status;
  87         }
  88     }
  89
  90     @Autowired
  91     private Rics rics;
  92     @Autowired
  93     private PolicyTypes policyTypes;
  94     @Autowired
  95     private Policies policies;
  96     @Autowired
  97     private A1ClientFactory a1ClientFactory;
  98     @Autowired
  99     private Services services;
 100
 101     private static final Logger logger = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
 102     private static Gson gson = new GsonBuilder() //
 103             .create(); //
 104
 105     @GetMapping(path = Consts.V2_API_ROOT + "/policy-types/{policytype_id:.+}") //
 106     @Operation(summary = "Returns a policy type definition") //
 107     @ApiResponses(value = { //
 108             @ApiResponse(responseCode = "200", //
 109                     description = "Policy type", //
 110                     content = @Content(schema = @Schema(implementation = PolicyTypeInfo.class))), //
 111             @ApiResponse(responseCode = "404", //
 112                     description = "Policy type is not found", //
 113                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class)))//
 114     })
 115     public ResponseEntity<Object> getPolicyType( //
 116             @PathVariable("policytype_id") String policyTypeId) throws EntityNotFoundException {
 117         PolicyType type = policyTypes.getType(policyTypeId);
 118         PolicyTypeInfo info = new PolicyTypeInfo(type.getSchema());
 119         return new ResponseEntity<>(gson.toJson(info), HttpStatus.OK);
 120     }
 121
 122     @GetMapping(path = Consts.V2_API_ROOT + "/policy-types", produces = MediaType.APPLICATION_JSON_VALUE)
 123     @Operation(summary = "Query policy type identities")
 124     @ApiResponses(value = { //
 125             @ApiResponse(responseCode = "200", //
 126                     description = "Policy type IDs", //
 127                     content = @Content(schema = @Schema(implementation = PolicyTypeIdList.class))), //
 128             @ApiResponse(responseCode = "404", //
 129                     description = "Near-RT RIC is not found", //
 130                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))) //
 131     })
 132     public ResponseEntity<Object> getPolicyTypes( //
 133             @Parameter(name = Consts.RIC_ID_PARAM, required = false, //
 134                     description = "Select types for the given Near-RT RIC identity.") //
 135             @RequestParam(name = Consts.RIC_ID_PARAM, required = false) String ricId,
 136
 137             @Parameter(name = Consts.TYPE_NAME_PARAM, required = false, //
 138                     description = "Select types with the given type name (type identity has the format <typename_version>)") //
 139             @RequestParam(name = Consts.TYPE_NAME_PARAM, required = false) String typeName,
 140
 141             @Parameter(name = Consts.COMPATIBLE_WITH_VERSION_PARAM, required = false, //
 142                     description = "Select types that are compatible with the given version. This parameter is only applicable in conjunction with "
 143                             + Consts.TYPE_NAME_PARAM
 144                             + ". As an example version 1.9.1 is compatible with 1.0.0 but not the other way around."
 145                             + " Matching types will be returned sorted in ascending order.") //
 146             @RequestParam(name = Consts.COMPATIBLE_WITH_VERSION_PARAM, required = false) String compatibleWithVersion
 147
 148     ) throws ServiceException {
 149
 150         if (compatibleWithVersion != null && typeName == null) {
 151             throw new ServiceException("Parameter " + Consts.COMPATIBLE_WITH_VERSION_PARAM + " can only be used when "
 152                     + Consts.TYPE_NAME_PARAM + " is given", HttpStatus.BAD_REQUEST);
 153         }
 154
 155         Collection<PolicyType> types =
 156                 ricId != null ? rics.getRic(ricId).getSupportedPolicyTypes() : this.policyTypes.getAll();
 157
 158         types = PolicyTypes.filterTypes(types, typeName, compatibleWithVersion);
 159         return new ResponseEntity<>(toPolicyTypeIdsJson(types), HttpStatus.OK);
 160     }
 161
 162     @GetMapping(path = Consts.V2_API_ROOT + "/policies/{policy_id:.+}", produces = MediaType.APPLICATION_JSON_VALUE)
 163     @Operation(summary = "Returns a policy") //
 164     @ApiResponses(value = { //
 165             @ApiResponse(responseCode = "200", //
 166                     description = "Policy found", //
 167                     content = @Content(schema = @Schema(implementation = PolicyInfo.class))), //
 168             @ApiResponse(responseCode = "404", //
 169                     description = "Policy is not found", //
 170                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))) //
 171     })
 172     public ResponseEntity<Object> getPolicy( //
 173             @PathVariable(name = Consts.POLICY_ID_PARAM, required = true) String id) throws EntityNotFoundException {
 174         Policy p = policies.getPolicy(id);
 175         return new ResponseEntity<>(gson.toJson(toPolicyInfo(p)), HttpStatus.OK);
 176     }
 177
 178     @DeleteMapping(Consts.V2_API_ROOT + "/policies/{policy_id:.+}")
 179     @Operation(summary = "Delete a policy")
 180     @ApiResponses(value = { //
 181             @ApiResponse(responseCode = "200", //
 182                     description = "Not used", //
 183                     content = @Content(schema = @Schema(implementation = VoidResponse.class))), //
 184             @ApiResponse(responseCode = "204", //
 185                     description = "Policy deleted", //
 186                     content = @Content(schema = @Schema(implementation = VoidResponse.class))), //
 187             @ApiResponse(responseCode = "404", //
 188                     description = "Policy is not found", //
 189                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))), //
 190             @ApiResponse(responseCode = "423", //
 191                     description = "Near-RT RIC is not operational", //
 192                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))) //
 193     })
 194     public Mono<ResponseEntity<Object>> deletePolicy( //
 195             @PathVariable(Consts.POLICY_ID_PARAM) String policyId) throws EntityNotFoundException {
 196         Policy policy = policies.getPolicy(policyId);
 197         keepServiceAlive(policy.getOwnerServiceId());
 198         Ric ric = policy.getRic();
 199
 200         return ric.getLock().lock(LockType.SHARED) //
 201                 .flatMap(notUsed -> assertRicStateIdle(ric)) //
 202                 .flatMap(notUsed -> a1ClientFactory.createA1Client(policy.getRic())) //
 203                 .doOnNext(notUsed -> policies.remove(policy)) //
 204                 .flatMap(client -> client.deletePolicy(policy)) //
 205                 .doOnNext(notUsed -> ric.getLock().unlockBlocking()) //
 206                 .doOnError(notUsed -> ric.getLock().unlockBlocking()) //
 207                 .map(notUsed -> new ResponseEntity<>(HttpStatus.NO_CONTENT)) //
 208                 .onErrorResume(this::handleException);
 209     }
 210
 211     @PutMapping(path = Consts.V2_API_ROOT + "/policies", produces = MediaType.APPLICATION_JSON_VALUE)
 212     @Operation(summary = "Create or update a policy")
 213     @ApiResponses(value = { //
 214             @ApiResponse(responseCode = "201", //
 215                     description = "Policy created", //
 216                     content = @Content(schema = @Schema(implementation = VoidResponse.class))), //
 217             @ApiResponse(responseCode = "200", //
 218                     description = "Policy updated", //
 219                     content = @Content(schema = @Schema(implementation = VoidResponse.class))), //
 220             @ApiResponse(responseCode = "423", //
 221                     description = "Near-RT RIC is not operational", //
 222                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))), //
 223             @ApiResponse(responseCode = "404", //
 224                     description = "Near-RT RIC or policy type is not found", //
 225                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))) //
 226     })
 227     public Mono<ResponseEntity<Object>> putPolicy(@RequestBody PolicyInfo policyInfo) throws EntityNotFoundException {
 228
 229         if (!policyInfo.validate()) {
 230             return ErrorResponse.createMono("Missing required parameter in body", HttpStatus.BAD_REQUEST);
 231         }
 232         String jsonString = gson.toJson(policyInfo.policyData);
 233         Ric ric = rics.get(policyInfo.ricId);
 234         PolicyType type = policyTypes.get(policyInfo.policyTypeId);
 235         keepServiceAlive(policyInfo.serviceId);
 236         if (ric == null || type == null) {
 237             throw new EntityNotFoundException("Near-RT RIC or policy type not found");
 238         }
 239         Policy policy = Policy.builder() //
 240                 .id(policyInfo.policyId) //
 241                 .json(jsonString) //
 242                 .type(type) //
 243                 .ric(ric) //
 244                 .ownerServiceId(policyInfo.serviceId) //
 245                 .lastModified(Instant.now()) //
 246                 .isTransient(policyInfo.isTransient) //
 247                 .statusNotificationUri(policyInfo.statusNotificationUri == null ? "" : policyInfo.statusNotificationUri) //
 248                 .build();
 249
 250         final boolean isCreate = this.policies.get(policy.getId()) == null;
 251
 252         return ric.getLock().lock(LockType.SHARED) //
 253                 .flatMap(notUsed -> assertRicStateIdle(ric)) //
 254                 .flatMap(notUsed -> checkSupportedType(ric, type)) //
 255                 .flatMap(notUsed -> validateModifiedPolicy(policy)) //
 256                 .flatMap(notUsed -> a1ClientFactory.createA1Client(ric)) //
 257                 .flatMap(client -> client.putPolicy(policy)) //
 258                 .doOnNext(notUsed -> policies.put(policy)) //
 259                 .doOnNext(notUsed -> ric.getLock().unlockBlocking()) //
 260                 .doOnError(trowable -> ric.getLock().unlockBlocking()) //
 261                 .flatMap(notUsed -> Mono.just(new ResponseEntity<>(isCreate ? HttpStatus.CREATED : HttpStatus.OK))) //
 262                 .onErrorResume(this::handleException);
 263     }
 264
 265     private Mono<ResponseEntity<Object>> handleException(Throwable throwable) {
 266         if (throwable instanceof WebClientResponseException) {
 267             WebClientResponseException e = (WebClientResponseException) throwable;
 268             return ErrorResponse.createMono(e.getResponseBodyAsString(), e.getStatusCode());
 269         } else if (throwable instanceof RejectionException) {
 270             RejectionException e = (RejectionException) throwable;
 271             return ErrorResponse.createMono(e.getMessage(), e.getStatus());
 272         } else {
 273             return ErrorResponse.createMono(throwable.getMessage(), HttpStatus.INTERNAL_SERVER_ERROR);
 274         }
 275     }
 276
 277     private Mono<Object> validateModifiedPolicy(Policy policy) {
 278         // Check that ric is not updated
 279         Policy current = this.policies.get(policy.getId());
 280         if (current != null && !current.getRic().id().equals(policy.getRic().id())) {
 281             RejectionException e = new RejectionException("Policy cannot change RIC, policyId: " + current.getId() + //
 282                     ", RIC ID: " + current.getRic().id() + //
 283                     ", new ID: " + policy.getRic().id(), HttpStatus.CONFLICT);
 284             logger.debug("Request rejected, {}", e.getMessage());
 285             return Mono.error(e);
 286         }
 287         return Mono.just("{}");
 288     }
 289
 290     private Mono<Object> checkSupportedType(Ric ric, PolicyType type) {
 291         if (!ric.isSupportingType(type.getId())) {
 292             logger.debug("Request rejected, type not supported, RIC: {}", ric);
 293             RejectionException e = new RejectionException(
 294                     "Type: " + type.getId() + " not supported by RIC: " + ric.id(), HttpStatus.NOT_FOUND);
 295             return Mono.error(e);
 296         }
 297         return Mono.just("{}");
 298     }
 299
 300     private Mono<Object> assertRicStateIdle(Ric ric) {
 301         if (ric.getState() == Ric.RicState.AVAILABLE) {
 302             return Mono.just("{}");
 303         } else {
 304             logger.debug("Request rejected Near-RT RIC not IDLE, ric: {}", ric);
 305             RejectionException e = new RejectionException(
 306                     "Near-RT RIC: is not operational, id: " + ric.id() + ", state: " + ric.getState(),
 307                     HttpStatus.LOCKED);
 308             return Mono.error(e);
 309         }
 310     }
 311
 312     static final String GET_POLICIES_QUERY_DETAILS =
 313             "Returns a list of A1 policies matching given search criteria. <br>" //
 314                     + "If several query parameters are defined, the policies matching all conditions are returned.";
 315
 316     @GetMapping(path = Consts.V2_API_ROOT + "/policy-instances", produces = MediaType.APPLICATION_JSON_VALUE)
 317     @Operation(summary = "Query for A1 policy instances", description = GET_POLICIES_QUERY_DETAILS)
 318     @ApiResponses(value = { //
 319             @ApiResponse(responseCode = "200", //
 320                     description = "Policies", //
 321                     content = @Content(schema = @Schema(implementation = PolicyInfoList.class))), //
 322             @ApiResponse(responseCode = "404", //
 323                     description = "Near-RT RIC, policy type or service not found", //
 324                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))) //
 325     })
 326     public ResponseEntity<Object> getPolicyInstances( //
 327             @Parameter(name = Consts.POLICY_TYPE_ID_PARAM, required = false,
 328                     description = "Select policies with a given type identity.") //
 329             @RequestParam(name = Consts.POLICY_TYPE_ID_PARAM, required = false) String typeId, //
 330             @Parameter(name = Consts.RIC_ID_PARAM, required = false,
 331                     description = "Select policies for a given Near-RT RIC identity.") //
 332             @RequestParam(name = Consts.RIC_ID_PARAM, required = false) String ric, //
 333             @Parameter(name = Consts.SERVICE_ID_PARAM, required = false,
 334                     description = "Select policies owned by a given service.") //
 335             @RequestParam(name = Consts.SERVICE_ID_PARAM, required = false) String service,
 336             @Parameter(name = Consts.TYPE_NAME_PARAM, required = false, //
 337                     description = "Select policies of a given type name (type identity has the format <typename_version>)") //
 338             @RequestParam(name = Consts.TYPE_NAME_PARAM, required = false) String typeName)
 339             throws EntityNotFoundException //
 340     {
 341         if ((typeId != null && this.policyTypes.get(typeId) == null)) {
 342             throw new EntityNotFoundException("Policy type identity not found");
 343         }
 344         if ((ric != null && this.rics.get(ric) == null)) {
 345             throw new EntityNotFoundException("Near-RT RIC not found");
 346         }
 347
 348         String filteredPolicies = policiesToJson(policies.filterPolicies(typeId, ric, service, typeName));
 349         return new ResponseEntity<>(filteredPolicies, HttpStatus.OK);
 350     }
 351
 352     @GetMapping(path = Consts.V2_API_ROOT + "/policies", produces = MediaType.APPLICATION_JSON_VALUE) //
 353     @Operation(summary = "Query policy identities", description = GET_POLICIES_QUERY_DETAILS) //
 354     @ApiResponses(value = { //
 355             @ApiResponse(responseCode = "200", //
 356                     description = "Policy identities", //
 357                     content = @Content(schema = @Schema(implementation = PolicyIdList.class))), //
 358             @ApiResponse(responseCode = "404", //
 359                     description = "Near-RT RIC or type not found", //
 360                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))) //
 361     })
 362     public ResponseEntity<Object> getPolicyIds( //
 363             @Parameter(name = Consts.POLICY_TYPE_ID_PARAM, required = false, //
 364                     description = "Select policies of a given policy type identity.") //
 365             @RequestParam(name = Consts.POLICY_TYPE_ID_PARAM, required = false) String policyTypeId, //
 366             @Parameter(name = Consts.RIC_ID_PARAM, required = false, //
 367                     description = "Select policies of a given Near-RT RIC identity.") //
 368             @RequestParam(name = Consts.RIC_ID_PARAM, required = false) String ricId, //
 369             @Parameter(name = Consts.SERVICE_ID_PARAM, required = false, //
 370                     description = "Select policies owned by a given service.") //
 371             @RequestParam(name = Consts.SERVICE_ID_PARAM, required = false) String serviceId,
 372             @Parameter(name = Consts.TYPE_NAME_PARAM, required = false, //
 373                     description = "Select policies of types with the given type name (type identity has the format <typename_version>)") //
 374             @RequestParam(name = Consts.TYPE_NAME_PARAM, required = false) String typeName)
 375             throws EntityNotFoundException //
 376     {
 377         if ((policyTypeId != null && this.policyTypes.get(policyTypeId) == null)) {
 378             throw new EntityNotFoundException("Policy type not found");
 379         }
 380         if ((ricId != null && this.rics.get(ricId) == null)) {
 381             throw new EntityNotFoundException("Near-RT RIC not found");
 382         }
 383
 384         String policyIdsJson = toPolicyIdsJson(policies.filterPolicies(policyTypeId, ricId, serviceId, typeName));
 385         return new ResponseEntity<>(policyIdsJson, HttpStatus.OK);
 386     }
 387
 388     @GetMapping(path = Consts.V2_API_ROOT + "/policies/{policy_id}/status", produces = MediaType.APPLICATION_JSON_VALUE)
 389     @Operation(summary = "Returns a policy status") //
 390     @ApiResponses(value = { //
 391             @ApiResponse(responseCode = "200", //
 392                     description = "Policy status", //
 393                     content = @Content(schema = @Schema(implementation = PolicyStatusInfo.class))), //
 394             @ApiResponse(responseCode = "404", //
 395                     description = "Policy is not found", //
 396                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))) //
 397     })
 398     public Mono<ResponseEntity<Object>> getPolicyStatus( //
 399             @PathVariable(Consts.POLICY_ID_PARAM) String policyId) throws EntityNotFoundException {
 400         Policy policy = policies.getPolicy(policyId);
 401
 402         return a1ClientFactory.createA1Client(policy.getRic()) //
 403                 .flatMap(client -> client.getPolicyStatus(policy).onErrorResume(e -> Mono.just("{}"))) //
 404                 .flatMap(status -> createPolicyStatus(policy, status)) //
 405                 .onErrorResume(this::handleException);
 406
 407     }
 408
 409     private Mono<ResponseEntity<Object>> createPolicyStatus(Policy policy, String statusFromNearRic) {
 410         PolicyStatusInfo info = new PolicyStatusInfo(policy.getLastModified(), fromJson(statusFromNearRic));
 411         String str = gson.toJson(info);
 412         return Mono.just(new ResponseEntity<>(str, HttpStatus.OK));
 413     }
 414
 415     private void keepServiceAlive(String name) {
 416         Service s = this.services.get(name);
 417         if (s != null) {
 418             s.keepAlive();
 419         }
 420     }
 421
 422     private PolicyInfo toPolicyInfo(Policy p) {
 423         PolicyInfo policyInfo = new PolicyInfo();
 424         policyInfo.policyId = p.getId();
 425         policyInfo.policyData = fromJson(p.getJson());
 426         policyInfo.ricId = p.getRic().id();
 427         policyInfo.policyTypeId = p.getType().getId();
 428         policyInfo.serviceId = p.getOwnerServiceId();
 429         policyInfo.isTransient = p.isTransient();
 430         if (!p.getStatusNotificationUri().isEmpty()) {
 431             policyInfo.statusNotificationUri = p.getStatusNotificationUri();
 432         }
 433         if (!policyInfo.validate()) {
 434             logger.error("BUG, all mandatory fields must be set");
 435         }
 436
 437         return policyInfo;
 438     }
 439
 440     private String policiesToJson(Collection<Policy> policies) {
 441         List<PolicyInfo> v = new ArrayList<>(policies.size());
 442         for (Policy p : policies) {
 443             v.add(toPolicyInfo(p));
 444         }
 445         PolicyInfoList list = new PolicyInfoList(v);
 446         return gson.toJson(list);
 447     }
 448
 449     private Object fromJson(String jsonStr) {
 450         return gson.fromJson(jsonStr, Object.class);
 451     }
 452
 453     private String toPolicyTypeIdsJson(Collection<PolicyType> types) {
 454         List<String> v = new ArrayList<>(types.size());
 455         for (PolicyType t : types) {
 456             v.add(t.getId());
 457         }
 458         PolicyTypeIdList ids = new PolicyTypeIdList(v);
 459         return gson.toJson(ids);
 460     }
 461
 462     private String toPolicyIdsJson(Collection<Policy> policies) {
 463         List<String> v = new ArrayList<>(policies.size());
 464         for (Policy p : policies) {
 465             v.add(p.getId());
 466         }
 467         return gson.toJson(new PolicyIdList(v));
 468     }
 469
 470 }