java/src/main/com/google/appengine/api/search/FacetResultValue.java

   1 package com.google.appengine.api.search;
   2
   3 import com.google.appengine.api.search.checkers.Preconditions;
   4
   5 import java.io.Serializable;
   6
   7 /**
   8  * Represents a single facet result value. The value has a label, a count, and a refinementToken.
   9  */
  10 public final class FacetResultValue implements Serializable {
  11
  12   private static final long serialVersionUID = 1171761338331659834L;
  13
  14   /**
  15    * Creates and returns a facet result value.
  16    *
  17    * @param label The label of the result returned by the backend that is the name of facet
  18    * for atom facets and the string "[start,end)" for number facets.
  19    * @param count an integer representing how many times this value is repeated in the result.
  20    * @param refinementToken the token string for further refinement of the search result. To
  21    * combine values for a single facet, add each of them separately to FacetRequest. There
  22    * will be a disjunction between refinements for the same facet.
  23    * @return an instance of {@link FacetResultValue}.
  24    * @throws IllegalArgumentException if label or refinementToken are empty.
  25    */
  26   public static FacetResultValue create(String label, int count, String refinementToken) {
  27     return new FacetResultValue(label, count, refinementToken);
  28   }
  29
  30   private final String label;
  31   private final int count;
  32   private final String refinementToken;
  33
  34   /**
  35    * Constructs a facet result value.
  36    */
  37   private FacetResultValue(String label, int count, String refinementToken) {
  38     Preconditions.checkNotNull(label, "label cannot be null");
  39     Preconditions.checkNotNull(refinementToken, "refinementToken cannot be null");
  40     Preconditions.checkArgument(!label.isEmpty(), "label cannot be empty");
  41     Preconditions.checkArgument(!refinementToken.isEmpty(), "refinementToken cannot be empty");
  42     this.label = label;
  43     this.count = count;
  44     this.refinementToken = refinementToken;
  45     checkValid();
  46   }
  47
  48   /**
  49    * Returns the label of this facet result value. The value label returned by the backend can be a
  50    * single facet value name, or a range label in "[start,end)" format.
  51    *
  52    * @return label as string
  53    */
  54   public String getLabel() {
  55     return label;
  56   }
  57
  58   /**
  59    * Returns the refinement token for this result value. This token can be used to
  60    * filter the result of new searches using this facet value.
  61    *
  62    * @return the refinement token string.
  63    */
  64   public String getRefinementToken() {
  65     return refinementToken;
  66   }
  67
  68   /**
  69    * Returns the count of the result value, which is an integer representing
  70    * how many times this value is repeated in the result for the given facet value or range.
  71    *
  72    * @return the count of this label in facet result.
  73    */
  74   public int getCount() {
  75     return count;
  76   }
  77
  78   private void checkValid() {
  79     Preconditions.checkState(label != null && !label.isEmpty(), "Label cannot be empty.");
  80     Preconditions.checkState(refinementToken != null && !refinementToken.isEmpty(),
  81         "Refinement token cannot be empty.");
  82   }
  83
  84   /**
  85    * Creates a new facet result value from the given protocol
  86    * buffer facet result value object.
  87    *
  88    * @param facetResultValue the facet result value protocol buffer to build
  89    * a facet result value object from.
  90    * @return the facet result value initialized from a facet result value protocol buffer.
  91    */
  92   static FacetResultValue withProtoMessage(
  93       SearchServicePb.FacetResultValue facetResultValue) {
  94     return create(
  95         facetResultValue.getName(),
  96         facetResultValue.getCount(),
  97         FacetRefinement.withProtoMessage(facetResultValue.getRefinement()).toTokenString());
  98   }
  99
 100   @Override
 101   public String toString() {
 102     return new Util.ToStringHelper("FacetResultValue")
 103         .addField("label", getLabel())
 104         .addField("count", getCount())
 105         .addField("refinementToken", getRefinementToken())
 106         .finish();
 107   }
 108 }