java/src/main/com/google/appengine/api/search/checkers/GetRequestChecker.java

   1 // Copyright 2011 Google Inc. All Rights Reserved.
   2
   3 package com.google.appengine.api.search.checkers;
   4
   5 import com.google.appengine.api.search.SearchServicePb.ListDocumentsParams;
   6 import com.google.common.base.Strings;
   7
   8 /**
   9  * Checks values of {@link com.google.appengine.api.search.GetRequest}.
  10  *
  11  */
  12 public class GetRequestChecker {
  13
  14   /**
  15    * Checks whether the number of documents to return is between 0 and the
  16    * maximum.
  17    *
  18    * @param limit the maximum number of documents to return in results list
  19    * @return the checked number of documents to return
  20    * @throws IllegalArgumentException if the number of documents to return
  21    * is out of range
  22    */
  23   public static int checkLimit(int limit) {
  24     Preconditions.checkArgument(limit >= 0 && limit <= SearchApiLimits.GET_RANGE_MAXIMUM_LIMIT,
  25         String.format("The limit %d must be between 0 and %d",
  26             limit, SearchApiLimits.GET_RANGE_MAXIMUM_LIMIT));
  27     return limit;
  28   }
  29
  30   /**
  31    * Checks whether the given start document Is legal.
  32    *
  33    * @param startDocId the start ocument Id to be checked.
  34    * @return the checked start document Id.
  35    * @throws IllegalArgumentException if the start document Id is illegal.
  36    */
  37   public static String checkStartDocId(String startDocId) {
  38     if (Strings.isNullOrEmpty(startDocId)) {
  39       return startDocId;
  40     }
  41     return DocumentChecker.checkDocumentId(startDocId);
  42   }
  43
  44   /**
  45    * Checks the values of the {@link ListDocumentsParams} params.
  46    *
  47    * @param params The {@link ListDocumentsParams} to check
  48    * @return the checked params
  49    * @throws IllegalArgumentException if some of the values of params are
  50    * invalid
  51    */
  52   public static ListDocumentsParams checkListDocumentsParams(ListDocumentsParams params) {
  53     IndexChecker.checkName(params.getIndexSpec().getName());
  54     if (params.hasLimit()) {
  55       checkLimit(params.getLimit());
  56     }
  57     if (params.hasStartDocId()) {
  58       DocumentChecker.checkDocumentId(params.getStartDocId());
  59     }
  60     return params;
  61   }
  62 }