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;
  47 import org.onap.ccsdk.oran.a1policymanagementservice.repository.Lock.LockType;
  48 import org.onap.ccsdk.oran.a1policymanagementservice.repository.Policies;
  49 import org.onap.ccsdk.oran.a1policymanagementservice.repository.Policy;
  50 import org.onap.ccsdk.oran.a1policymanagementservice.repository.PolicyType;
  51 import org.onap.ccsdk.oran.a1policymanagementservice.repository.PolicyTypes;
  52 import org.onap.ccsdk.oran.a1policymanagementservice.repository.Ric;
  53 import org.onap.ccsdk.oran.a1policymanagementservice.repository.Rics;
  54 import org.onap.ccsdk.oran.a1policymanagementservice.repository.Service;
  55 import org.onap.ccsdk.oran.a1policymanagementservice.repository.Services;
  56 import org.slf4j.Logger;
  57 import org.slf4j.LoggerFactory;
  58 import org.springframework.beans.factory.annotation.Autowired;
  59 import org.springframework.http.HttpStatus;
  60 import org.springframework.http.MediaType;
  61 import org.springframework.http.ResponseEntity;
  62 import org.springframework.web.bind.annotation.DeleteMapping;
  63 import org.springframework.web.bind.annotation.GetMapping;
  64 import org.springframework.web.bind.annotation.PathVariable;
  65 import org.springframework.web.bind.annotation.PutMapping;
  66 import org.springframework.web.bind.annotation.RequestBody;
  67 import org.springframework.web.bind.annotation.RequestParam;
  68 import org.springframework.web.bind.annotation.RestController;
  69 import org.springframework.web.reactive.function.client.WebClientResponseException;
  70 import reactor.core.publisher.Mono;
  71
  72 @RestController("PolicyControllerV2")
  73 @Tag(name = PolicyController.API_NAME)
  74 public class PolicyController {
  75
  76     public static final String API_NAME = "A1 Policy Management";
  77     public static final String API_DESCRIPTION = "";
  78
  79     public static class RejectionException extends Exception {
  80         private static final long serialVersionUID = 1L;
  81
  82         @Getter
  83         private final HttpStatus status;
  84
  85         public RejectionException(String message, HttpStatus status) {
  86             super(message);
  87             this.status = status;
  88         }
  89     }
  90
  91     @Autowired
  92     private Rics rics;
  93     @Autowired
  94     private PolicyTypes policyTypes;
  95     @Autowired
  96     private Policies policies;
  97     @Autowired
  98     private A1ClientFactory a1ClientFactory;
  99     @Autowired
 100     private Services services;
 101
 102     private static final Logger logger = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
 103     private static Gson gson = new GsonBuilder() //
 104             .create(); //
 105
 106     @GetMapping(path = Consts.V2_API_ROOT + "/policy-types/{policytype_id:.+}") //
 107     @Operation(summary = "Returns a policy type definition") //
 108     @ApiResponses(value = { //
 109             @ApiResponse(responseCode = "200", //
 110                     description = "Policy type", //
 111                     content = @Content(schema = @Schema(implementation = PolicyTypeInfo.class))), //
 112             @ApiResponse(responseCode = "404", //
 113                     description = "Policy type is not found", //
 114                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class)))//
 115     })
 116     public ResponseEntity<Object> getPolicyType( //
 117             @PathVariable("policytype_id") String policyTypeId) throws EntityNotFoundException {
 118         PolicyType type = policyTypes.getType(policyTypeId);
 119         PolicyTypeInfo info = new PolicyTypeInfo(type.getSchema());
 120         return new ResponseEntity<>(gson.toJson(info), HttpStatus.OK);
 121     }
 122
 123     @GetMapping(path = Consts.V2_API_ROOT + "/policy-types", produces = MediaType.APPLICATION_JSON_VALUE)
 124     @Operation(summary = "Query policy type identities")
 125     @ApiResponses(value = { //
 126             @ApiResponse(responseCode = "200", //
 127                     description = "Policy type IDs", //
 128                     content = @Content(schema = @Schema(implementation = PolicyTypeIdList.class))), //
 129             @ApiResponse(responseCode = "404", //
 130                     description = "Near-RT RIC is not found", //
 131                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))) //
 132     })
 133     public ResponseEntity<Object> getPolicyTypes( //
 134             @Parameter(name = Consts.RIC_ID_PARAM, required = false, //
 135                     description = "Select types for the given Near-RT RIC identity.") //
 136             @RequestParam(name = Consts.RIC_ID_PARAM, required = false) String ricId,
 137
 138             @Parameter(name = Consts.TYPE_NAME_PARAM, required = false, //
 139                     description = "Select types with the given type name (type identity has the format <typename_version>)") //
 140             @RequestParam(name = Consts.TYPE_NAME_PARAM, required = false) String typeName,
 141
 142             @Parameter(name = Consts.COMPATIBLE_WITH_VERSION_PARAM, required = false, //
 143                     description = "Select types that are compatible with the given version. This parameter is only applicable in conjunction with "
 144                             + Consts.TYPE_NAME_PARAM
 145                             + ". As an example version 1.9.1 is compatible with 1.0.0 but not the other way around."
 146                             + " Matching types will be returned sorted in ascending order.") //
 147             @RequestParam(name = Consts.COMPATIBLE_WITH_VERSION_PARAM, required = false) String compatibleWithVersion
 148
 149     ) throws ServiceException {
 150
 151         if (compatibleWithVersion != null && typeName == null) {
 152             throw new ServiceException("Parameter " + Consts.COMPATIBLE_WITH_VERSION_PARAM + " can only be used when "
 153                     + Consts.TYPE_NAME_PARAM + " is given", HttpStatus.BAD_REQUEST);
 154         }
 155
 156         Collection<PolicyType> types =
 157                 ricId != null ? rics.getRic(ricId).getSupportedPolicyTypes() : this.policyTypes.getAll();
 158
 159         types = PolicyTypes.filterTypes(types, typeName, compatibleWithVersion);
 160         return new ResponseEntity<>(toPolicyTypeIdsJson(types), HttpStatus.OK);
 161     }
 162
 163     @GetMapping(path = Consts.V2_API_ROOT + "/policies/{policy_id:.+}", produces = MediaType.APPLICATION_JSON_VALUE)
 164     @Operation(summary = "Returns a policy") //
 165     @ApiResponses(value = { //
 166             @ApiResponse(responseCode = "200", //
 167                     description = "Policy found", //
 168                     content = @Content(schema = @Schema(implementation = PolicyInfo.class))), //
 169             @ApiResponse(responseCode = "404", //
 170                     description = "Policy is not found", //
 171                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))) //
 172     })
 173     public ResponseEntity<Object> getPolicy( //
 174             @PathVariable(name = Consts.POLICY_ID_PARAM, required = true) String id) throws EntityNotFoundException {
 175         Policy p = policies.getPolicy(id);
 176         return new ResponseEntity<>(gson.toJson(toPolicyInfo(p)), HttpStatus.OK);
 177     }
 178
 179     @DeleteMapping(Consts.V2_API_ROOT + "/policies/{policy_id:.+}")
 180     @Operation(summary = "Delete a policy")
 181     @ApiResponses(value = { //
 182             @ApiResponse(responseCode = "200", //
 183                     description = "Not used", //
 184                     content = @Content(schema = @Schema(implementation = VoidResponse.class))), //
 185             @ApiResponse(responseCode = "204", //
 186                     description = "Policy deleted", //
 187                     content = @Content(schema = @Schema(implementation = VoidResponse.class))), //
 188             @ApiResponse(responseCode = "404", //
 189                     description = "Policy is not found", //
 190                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))), //
 191             @ApiResponse(responseCode = "423", //
 192                     description = "Near-RT RIC is not operational", //
 193                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))) //
 194     })
 195     public Mono<ResponseEntity<Object>> deletePolicy( //
 196             @PathVariable(Consts.POLICY_ID_PARAM) String policyId) throws EntityNotFoundException {
 197         Policy policy = policies.getPolicy(policyId);
 198         keepServiceAlive(policy.getOwnerServiceId());
 199
 200         return policy.getRic().getLock().lock(LockType.SHARED, "deletePolicy") //
 201                 .flatMap(grant -> deletePolicy(grant, policy));
 202     }
 203
 204     Mono<ResponseEntity<Object>> deletePolicy(Lock.Grant grant, Policy policy) {
 205         return assertRicStateIdle(policy.getRic()) //
 206                 .flatMap(notUsed -> a1ClientFactory.createA1Client(policy.getRic())) //
 207                 .doOnNext(notUsed -> policies.remove(policy)) //
 208                 .doFinally(x -> grant.unlockBlocking()) //
 209                 .flatMap(client -> client.deletePolicy(policy)) //
 210                 .map(notUsed -> new ResponseEntity<>(HttpStatus.NO_CONTENT)) //
 211                 .onErrorResume(this::handleException);
 212     }
 213
 214     @PutMapping(path = Consts.V2_API_ROOT + "/policies", produces = MediaType.APPLICATION_JSON_VALUE)
 215     @Operation(summary = "Create or update a policy")
 216     @ApiResponses(value = { //
 217             @ApiResponse(responseCode = "201", //
 218                     description = "Policy created", //
 219                     content = @Content(schema = @Schema(implementation = VoidResponse.class))), //
 220             @ApiResponse(responseCode = "200", //
 221                     description = "Policy updated", //
 222                     content = @Content(schema = @Schema(implementation = VoidResponse.class))), //
 223             @ApiResponse(responseCode = "423", //
 224                     description = "Near-RT RIC is not operational", //
 225                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))), //
 226             @ApiResponse(responseCode = "404", //
 227                     description = "Near-RT RIC or policy type is not found", //
 228                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))) //
 229     })
 230     public Mono<ResponseEntity<Object>> putPolicy(@RequestBody PolicyInfo policyInfo) throws EntityNotFoundException {
 231
 232         if (!policyInfo.validate()) {
 233             return ErrorResponse.createMono("Missing required parameter in body", HttpStatus.BAD_REQUEST);
 234         }
 235         String jsonString = gson.toJson(policyInfo.policyData);
 236         Ric ric = rics.get(policyInfo.ricId);
 237         PolicyType type = policyTypes.get(policyInfo.policyTypeId);
 238         keepServiceAlive(policyInfo.serviceId);
 239         if (ric == null || type == null) {
 240             throw new EntityNotFoundException("Near-RT RIC or policy type not found");
 241         }
 242         Policy policy = Policy.builder() //
 243                 .id(policyInfo.policyId) //
 244                 .json(jsonString) //
 245                 .type(type) //
 246                 .ric(ric) //
 247                 .ownerServiceId(policyInfo.serviceId) //
 248                 .lastModified(Instant.now()) //
 249                 .isTransient(policyInfo.isTransient) //
 250                 .statusNotificationUri(policyInfo.statusNotificationUri == null ? "" : policyInfo.statusNotificationUri) //
 251                 .build();
 252
 253         return ric.getLock().lock(LockType.SHARED, "putPolicy") //
 254                 .flatMap(grant -> putPolicy(grant, policy));
 255     }
 256
 257     private Mono<ResponseEntity<Object>> putPolicy(Lock.Grant grant, Policy policy) {
 258         final boolean isCreate = this.policies.get(policy.getId()) == null;
 259         final Ric ric = policy.getRic();
 260
 261         return assertRicStateIdle(ric) //
 262                 .flatMap(notUsed -> checkSupportedType(ric, policy.getType())) //
 263                 .flatMap(notUsed -> validateModifiedPolicy(policy)) //
 264                 .flatMap(notUsed -> a1ClientFactory.createA1Client(ric)) //
 265                 .flatMap(client -> client.putPolicy(policy)) //
 266                 .doOnNext(notUsed -> policies.put(policy)) //
 267                 .doFinally(x -> grant.unlockBlocking()) //
 268                 .flatMap(notUsed -> Mono.just(new ResponseEntity<>(isCreate ? HttpStatus.CREATED : HttpStatus.OK))) //
 269                 .onErrorResume(this::handleException);
 270
 271     }
 272
 273     private Mono<ResponseEntity<Object>> handleException(Throwable throwable) {
 274         if (throwable instanceof WebClientResponseException) {
 275             WebClientResponseException e = (WebClientResponseException) throwable;
 276             return ErrorResponse.createMono(e.getResponseBodyAsString(), e.getStatusCode());
 277         } else if (throwable instanceof RejectionException) {
 278             RejectionException e = (RejectionException) throwable;
 279             return ErrorResponse.createMono(e.getMessage(), e.getStatus());
 280         } else {
 281             return ErrorResponse.createMono(throwable.getMessage(), HttpStatus.INTERNAL_SERVER_ERROR);
 282         }
 283     }
 284
 285     private Mono<Object> validateModifiedPolicy(Policy policy) {
 286         // Check that ric is not updated
 287         Policy current = this.policies.get(policy.getId());
 288         if (current != null && !current.getRic().id().equals(policy.getRic().id())) {
 289             RejectionException e = new RejectionException("Policy cannot change RIC, policyId: " + current.getId() + //
 290                     ", RIC ID: " + current.getRic().id() + //
 291                     ", new ID: " + policy.getRic().id(), HttpStatus.CONFLICT);
 292             logger.debug("Request rejected, {}", e.getMessage());
 293             return Mono.error(e);
 294         }
 295         return Mono.just("{}");
 296     }
 297
 298     private Mono<Object> checkSupportedType(Ric ric, PolicyType type) {
 299         if (!ric.isSupportingType(type.getId())) {
 300             logger.debug("Request rejected, type not supported, RIC: {}", ric);
 301             RejectionException e = new RejectionException(
 302                     "Type: " + type.getId() + " not supported by RIC: " + ric.id(), HttpStatus.NOT_FOUND);
 303             return Mono.error(e);
 304         }
 305         return Mono.just("{}");
 306     }
 307
 308     private Mono<Object> assertRicStateIdle(Ric ric) {
 309         if (ric.getState() == Ric.RicState.AVAILABLE) {
 310             return Mono.just("{}");
 311         } else {
 312             logger.debug("Request rejected Near-RT RIC not IDLE, ric: {}", ric);
 313             RejectionException e = new RejectionException(
 314                     "Near-RT RIC: is not operational, id: " + ric.id() + ", state: " + ric.getState(),
 315                     HttpStatus.LOCKED);
 316             return Mono.error(e);
 317         }
 318     }
 319
 320     static final String GET_POLICIES_QUERY_DETAILS =
 321             "Returns a list of A1 policies matching given search criteria. <br>" //
 322                     + "If several query parameters are defined, the policies matching all conditions are returned.";
 323
 324     @GetMapping(path = Consts.V2_API_ROOT + "/policy-instances", produces = MediaType.APPLICATION_JSON_VALUE)
 325     @Operation(summary = "Query for A1 policy instances", description = GET_POLICIES_QUERY_DETAILS)
 326     @ApiResponses(value = { //
 327             @ApiResponse(responseCode = "200", //
 328                     description = "Policies", //
 329                     content = @Content(schema = @Schema(implementation = PolicyInfoList.class))), //
 330             @ApiResponse(responseCode = "404", //
 331                     description = "Near-RT RIC, policy type or service not found", //
 332                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))) //
 333     })
 334     public ResponseEntity<Object> getPolicyInstances( //
 335             @Parameter(name = Consts.POLICY_TYPE_ID_PARAM, required = false,
 336                     description = "Select policies with a given type identity.") //
 337             @RequestParam(name = Consts.POLICY_TYPE_ID_PARAM, required = false) String typeId, //
 338             @Parameter(name = Consts.RIC_ID_PARAM, required = false,
 339                     description = "Select policies for a given Near-RT RIC identity.") //
 340             @RequestParam(name = Consts.RIC_ID_PARAM, required = false) String ric, //
 341             @Parameter(name = Consts.SERVICE_ID_PARAM, required = false,
 342                     description = "Select policies owned by a given service.") //
 343             @RequestParam(name = Consts.SERVICE_ID_PARAM, required = false) String service,
 344             @Parameter(name = Consts.TYPE_NAME_PARAM, required = false, //
 345                     description = "Select policies of a given type name (type identity has the format <typename_version>)") //
 346             @RequestParam(name = Consts.TYPE_NAME_PARAM, required = false) String typeName)
 347             throws EntityNotFoundException //
 348     {
 349         if ((typeId != null && this.policyTypes.get(typeId) == null)) {
 350             throw new EntityNotFoundException("Policy type identity not found");
 351         }
 352         if ((ric != null && this.rics.get(ric) == null)) {
 353             throw new EntityNotFoundException("Near-RT RIC not found");
 354         }
 355
 356         String filteredPolicies = policiesToJson(policies.filterPolicies(typeId, ric, service, typeName));
 357         return new ResponseEntity<>(filteredPolicies, HttpStatus.OK);
 358     }
 359
 360     @GetMapping(path = Consts.V2_API_ROOT + "/policies", produces = MediaType.APPLICATION_JSON_VALUE) //
 361     @Operation(summary = "Query policy identities", description = GET_POLICIES_QUERY_DETAILS) //
 362     @ApiResponses(value = { //
 363             @ApiResponse(responseCode = "200", //
 364                     description = "Policy identities", //
 365                     content = @Content(schema = @Schema(implementation = PolicyIdList.class))), //
 366             @ApiResponse(responseCode = "404", //
 367                     description = "Near-RT RIC or type not found", //
 368                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))) //
 369     })
 370     public ResponseEntity<Object> getPolicyIds( //
 371             @Parameter(name = Consts.POLICY_TYPE_ID_PARAM, required = false, //
 372                     description = "Select policies of a given policy type identity.") //
 373             @RequestParam(name = Consts.POLICY_TYPE_ID_PARAM, required = false) String policyTypeId, //
 374             @Parameter(name = Consts.RIC_ID_PARAM, required = false, //
 375                     description = "Select policies of a given Near-RT RIC identity.") //
 376             @RequestParam(name = Consts.RIC_ID_PARAM, required = false) String ricId, //
 377             @Parameter(name = Consts.SERVICE_ID_PARAM, required = false, //
 378                     description = "Select policies owned by a given service.") //
 379             @RequestParam(name = Consts.SERVICE_ID_PARAM, required = false) String serviceId,
 380             @Parameter(name = Consts.TYPE_NAME_PARAM, required = false, //
 381                     description = "Select policies of types with the given type name (type identity has the format <typename_version>)") //
 382             @RequestParam(name = Consts.TYPE_NAME_PARAM, required = false) String typeName)
 383             throws EntityNotFoundException //
 384     {
 385         if ((policyTypeId != null && this.policyTypes.get(policyTypeId) == null)) {
 386             throw new EntityNotFoundException("Policy type not found");
 387         }
 388         if ((ricId != null && this.rics.get(ricId) == null)) {
 389             throw new EntityNotFoundException("Near-RT RIC not found");
 390         }
 391
 392         String policyIdsJson = toPolicyIdsJson(policies.filterPolicies(policyTypeId, ricId, serviceId, typeName));
 393         return new ResponseEntity<>(policyIdsJson, HttpStatus.OK);
 394     }
 395
 396     @GetMapping(path = Consts.V2_API_ROOT + "/policies/{policy_id}/status", produces = MediaType.APPLICATION_JSON_VALUE)
 397     @Operation(summary = "Returns a policy status") //
 398     @ApiResponses(value = { //
 399             @ApiResponse(responseCode = "200", //
 400                     description = "Policy status", //
 401                     content = @Content(schema = @Schema(implementation = PolicyStatusInfo.class))), //
 402             @ApiResponse(responseCode = "404", //
 403                     description = "Policy is not found", //
 404                     content = @Content(schema = @Schema(implementation = ErrorResponse.ErrorInfo.class))) //
 405     })
 406     public Mono<ResponseEntity<Object>> getPolicyStatus( //
 407             @PathVariable(Consts.POLICY_ID_PARAM) String policyId) throws EntityNotFoundException {
 408         Policy policy = policies.getPolicy(policyId);
 409
 410         return a1ClientFactory.createA1Client(policy.getRic()) //
 411                 .flatMap(client -> client.getPolicyStatus(policy).onErrorResume(e -> Mono.just("{}"))) //
 412                 .flatMap(status -> createPolicyStatus(policy, status)) //
 413                 .onErrorResume(this::handleException);
 414
 415     }
 416
 417     private Mono<ResponseEntity<Object>> createPolicyStatus(Policy policy, String statusFromNearRic) {
 418         PolicyStatusInfo info = new PolicyStatusInfo(policy.getLastModified(), fromJson(statusFromNearRic));
 419         String str = gson.toJson(info);
 420         return Mono.just(new ResponseEntity<>(str, HttpStatus.OK));
 421     }
 422
 423     private void keepServiceAlive(String name) {
 424         Service s = this.services.get(name);
 425         if (s != null) {
 426             s.keepAlive();
 427         }
 428     }
 429
 430     private PolicyInfo toPolicyInfo(Policy p) {
 431         PolicyInfo policyInfo = new PolicyInfo();
 432         policyInfo.policyId = p.getId();
 433         policyInfo.policyData = fromJson(p.getJson());
 434         policyInfo.ricId = p.getRic().id();
 435         policyInfo.policyTypeId = p.getType().getId();
 436         policyInfo.serviceId = p.getOwnerServiceId();
 437         policyInfo.isTransient = p.isTransient();
 438         if (!p.getStatusNotificationUri().isEmpty()) {
 439             policyInfo.statusNotificationUri = p.getStatusNotificationUri();
 440         }
 441         if (!policyInfo.validate()) {
 442             logger.error("BUG, all mandatory fields must be set");
 443         }
 444
 445         return policyInfo;
 446     }
 447
 448     private String policiesToJson(Collection<Policy> policies) {
 449         List<PolicyInfo> v = new ArrayList<>(policies.size());
 450         for (Policy p : policies) {
 451             v.add(toPolicyInfo(p));
 452         }
 453         PolicyInfoList list = new PolicyInfoList(v);
 454         return gson.toJson(list);
 455     }
 456
 457     private Object fromJson(String jsonStr) {
 458         return gson.fromJson(jsonStr, Object.class);
 459     }
 460
 461     private String toPolicyTypeIdsJson(Collection<PolicyType> types) {
 462         List<String> v = new ArrayList<>(types.size());
 463         for (PolicyType t : types) {
 464             v.add(t.getId());
 465         }
 466         PolicyTypeIdList ids = new PolicyTypeIdList(v);
 467         return gson.toJson(ids);
 468     }
 469
 470     private String toPolicyIdsJson(Collection<Policy> policies) {
 471         List<String> v = new ArrayList<>(policies.size());
 472         for (Policy p : policies) {
 473             v.add(p.getId());
 474         }
 475         return gson.toJson(new PolicyIdList(v));
 476     }
 477
 478 }