Elasticsearch提供完整的java API用来支持facets。在查询的过程中，将需要计数的facets添加到FacetBuilders中。然后将该FacetBuilders条件到查询请求中。
SearchResponse sr = node.client().prepareSearch()
.setQuery( /* your query */ )
.addFacet( /* add a facet */ )
.execute().actionGet();
为了构建facets请求，需要用到FacetBuilders帮助类。你只需要在你的程序中导入它即可。
import org.elasticsearch.search.facet.FacetBuilders.*;
下面的例子新建一个facet请求
FacetBuilders.termsFacet("f")
.field("brand")
.size(10);
import org.elasticsearch.search.facet.terms.*;
// sr is here your SearchResponse object
TermsFacet f = (TermsFacet) sr.getFacets().facetsAsMap().get("f");
f.getTotalCount(); // Total terms doc count
f.getOtherCount(); // Not shown terms doc count
f.getMissingCount(); // Without term doc count
// For each entry
for (TermsFacet.Entry entry : f) {
entry.getTerm(); // Term
entry.getCount(); // Doc count
}
下面的例子新建一个facet请求
FacetBuilders.rangeFacet("f")
.field("price") // Field to compute on
.addUnboundedFrom(3) // from -infinity to 3 (excluded)
.addRange(3, 6) // from 3 to 6 (excluded)
.addUnboundedTo(6); // from 6 to +infinity
import org.elasticsearch.search.facet.range.*;
// sr is here your SearchResponse object
RangeFacet f = (RangeFacet) sr.getFacets().facetsAsMap().get("f");
// For each entry
for (RangeFacet.Entry entry : f) {
entry.getFrom(); // Range from requested
entry.getTo(); // Range to requested
entry.getCount(); // Doc count
entry.getMin(); // Min value
entry.getMax(); // Max value
entry.getMean(); // Mean
entry.getTotal(); // Sum of values
}
下面的例子新建一个facet请求
HistogramFacetBuilder facet = FacetBuilders.histogramFacet("f")
.field("price")
.interval(1);
import org.elasticsearch.search.facet.histogram.*;
// sr is here your SearchResponse object
HistogramFacet f = (HistogramFacet) sr.getFacets().facetsAsMap().get("f");
// For each entry
for (HistogramFacet.Entry entry : f) {
entry.getKey(); // Key (X-Axis)
entry.getCount(); // Doc count (Y-Axis)
}
下面的例子新建一个facet请求
FacetBuilders.dateHistogramFacet("f")
.field("date") // Your date field
.interval("year"); // You can also use "quarter", "month", "week", "day",
// "hour" and "minute" or notation like "1.5h" or "2w"
import org.elasticsearch.search.facet.datehistogram.*;
// sr is here your SearchResponse object
DateHistogramFacet f = (DateHistogramFacet) sr.getFacets().facetsAsMap().get("f");
// For each entry
for (DateHistogramFacet.Entry entry : f) {
entry.getTime(); // Date in ms since epoch (X-Axis)
entry.getCount(); // Doc count (Y-Axis)
}
下面的例子新建一个facet请求
FacetBuilders.filterFacet("f",
FilterBuilders.termFilter("brand", "heineken")); // Your Filter here
import org.elasticsearch.search.facet.filter.*;
// sr is here your SearchResponse object
FilterFacet f = (FilterFacet) sr.getFacets().facetsAsMap().get("f");
f.getCount(); // Number of docs that matched
下面的例子新建一个facet请求
FacetBuilders.queryFacet("f",
QueryBuilders.matchQuery("brand", "heineken"));
import org.elasticsearch.search.facet.query.*;
// sr is here your SearchResponse object
QueryFacet f = (QueryFacet) sr.getFacets().facetsAsMap().get("f");
f.getCount(); // Number of docs that matched
下面的例子新建一个facet请求
FacetBuilders.statisticalFacet("f")
.field("price");
import org.elasticsearch.search.facet.statistical.*;
// sr is here your SearchResponse object
StatisticalFacet f = (StatisticalFacet) sr.getFacets().facetsAsMap().get("f");
f.getCount(); // Doc count
f.getMin(); // Min value
f.getMax(); // Max value
f.getMean(); // Mean
f.getTotal(); // Sum of values
f.getStdDeviation(); // Standard Deviation
f.getSumOfSquares(); // Sum of Squares
f.getVariance(); // Variance
下面的例子新建一个facet请求
FacetBuilders.termsStatsFacet("f")
.keyField("brand")
.valueField("price");
// sr is here your SearchResponse object
TermsStatsFacet f = (TermsStatsFacet) sr.getFacets().facetsAsMap().get("f");
f.getTotalCount(); // Total terms doc count
f.getOtherCount(); // Not shown terms doc count
f.getMissingCount(); // Without term doc count
// For each entry
for (TermsStatsFacet.Entry entry : f) {
entry.getTerm(); // Term
entry.getCount(); // Doc count
entry.getMin(); // Min value
entry.getMax(); // Max value
entry.getMean(); // Mean
entry.getTotal(); // Sum of values
}
下面的例子新建一个facet请求
FacetBuilders.geoDistanceFacet("f")
.field("pin.location") // Field containing coordinates we want to compare with
.point(40, -70) // Point from where we start (0)
.addUnboundedFrom(10) // 0 to 10 km (excluded)
.addRange(10, 20) // 10 to 20 km (excluded)
.addRange(20, 100) // 20 to 100 km (excluded)
.addUnboundedTo(100) // from 100 km to infinity (and beyond ;-) )
.unit(DistanceUnit.KILOMETERS); // All distances are in kilometers. Can be MILES
// sr is here your SearchResponse object
GeoDistanceFacet f = (GeoDistanceFacet) sr.getFacets().facetsAsMap().get("f");
// For each entry
for (GeoDistanceFacet.Entry entry : f) {
entry.getFrom(); // Distance from requested
entry.getTo(); // Distance to requested
entry.getCount(); // Doc count
entry.getMin(); // Min value
entry.getMax(); // Max value
entry.getTotal(); // Sum of values
entry.getMean(); // Mean
}
默认情况下，不管过滤器存在与否，facet都是作用在查询的结果集上。如果你需要计数带有过滤器的facet，你能够通过AbstractFacetBuilder#facetFilter(FilterBuilder)添加
过滤器到任何facet上。
FacetBuilders
.termsFacet("f").field("brand") // Your facet
.facetFilter( // Your filter here
FilterBuilders.termFilter("colour", "pale")
);
例如，你可以在你的查询中重用创建的过滤器
// A common filter
FilterBuilder filter = FilterBuilders.termFilter("colour", "pale");
TermsFacetBuilder facet = FacetBuilders.termsFacet("f")
.field("brand")
.facetFilter(filter); // We apply it to the facet
SearchResponse sr = node.client().prepareSearch()
.setQuery(QueryBuilders.matchAllQuery())
.setFilter(filter) // We apply it to the query
.addFacet(facet)
.execute().actionGet();
默认情况下，facet作用在查询的结果集上。但是，不管是哪个查询，你可以用global参数去计算来自于索引中的所有文档的facet。
TermsFacetBuilder facet = FacetBuilders.termsFacet("f")
.field("brand")
.global(true);