java/src/main/com/google/appengine/api/conversion/ConversionHelper.java

   1 // Copyright 2011 Google Inc. All Rights Reserved.
   2
   3 package com.google.appengine.api.conversion;
   4
   5 import com.google.common.base.Preconditions;
   6 import com.google.common.base.StringUtil;
   7
   8 import java.util.List;
   9
  10 /**
  11  * Utility methods to validate data structures.
  12  *
  13  */
  14 class ConversionHelper {
  15
  16   private ConversionHelper() {
  17   }
  18
  19   /**
  20     * Validates the size of document is not over limit, returns itself if the
  21     * validation passes.
  22     *
  23     * @throws IllegalArgumentException if the size of document is over limit
  24     */
  25   static Document validateDocumentSize(Document document) {
  26     Preconditions.checkNotNull(document);
  27     int size = 0;
  28     for (Asset asset : document.getAssets()) {
  29       size += asset.getData().length;
  30     }
  31     Preconditions.checkArgument(size <= ConversionService.CONVERSION_MAX_SIZE_BYTES,
  32         String.format("Each conversion should not be over %d bytes.",
  33             ConversionService.CONVERSION_MAX_SIZE_BYTES));
  34     return document;
  35   }
  36
  37   /**
  38     * Validates the document can be used as input for a conversion, returns
  39     * itself if the validation passes.
  40     *
  41     * @throws IllegalArgumentException if additional asset name is null, empty
  42     *         or comprises only whitespace characters
  43     */
  44   static Document validateInputDoc(Document document) {
  45     Preconditions.checkNotNull(document);
  46     List<Asset> assets = document.getAssets();
  47     for (Asset asset : assets.subList(1, assets.size())) {
  48       Preconditions.checkArgument(!StringUtil.isEmptyOrWhitespace(asset.getName()),
  49           "Additional asset name should not be null, empty or comprises only whitespaces");
  50     }
  51     return document;
  52   }
  53 }