DATAES-26 - added support for histogram facets

src/main/java/org/springframework/data/elasticsearch/core/facet/FacetMapper.java

@@ -29,6 +29,10 @@ public class FacetMapper {
             return parseStatistical((StatisticalFacet) facet);
         }
 
+        if (facet instanceof HistogramFacet) {
+            return parseHistogram((HistogramFacet) facet);
+        }
+
         return null;
     }
 
@@ -52,4 +56,12 @@ public class FacetMapper {
         return new StatisticalResult(facet.getName(), facet.getCount(), facet.getMax(), facet.getMin(), facet.getMean(), facet.getStdDeviation(), facet.getSumOfSquares(), facet.getTotal(), facet.getVariance());
     }
 
+    private static FacetResult parseHistogram(HistogramFacet facet) {
+        List<IntervalUnit> entries = new ArrayList<IntervalUnit>();
+        for (HistogramFacet.Entry entry : facet.getEntries()) {
+            entries.add(new IntervalUnit(entry.getKey(), entry.getCount(), entry.getTotalCount(), entry.getTotal(), entry.getMean(), entry.getMin(), entry.getMax()));
+        }
+        return new HistogramResult(facet.getName(), entries);
+    }
+
 }

src/main/java/org/springframework/data/elasticsearch/core/facet/request/HistogramFacetRequest.java

@@ -0,0 +1,54 @@
+package org.springframework.data.elasticsearch.core.facet.request;
+
+import org.apache.commons.lang.StringUtils;
+import org.apache.commons.lang.math.NumberUtils;
+import org.elasticsearch.search.facet.FacetBuilder;
+import org.elasticsearch.search.facet.FacetBuilders;
+import org.elasticsearch.search.facet.histogram.HistogramFacetBuilder;
+import org.springframework.data.elasticsearch.core.facet.AbstractFacetRequest;
+import org.springframework.util.Assert;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * @author Artur Konczak
+ */
+public class HistogramFacetRequest extends AbstractFacetRequest {
+
+    private String field;
+    private long interval;
+    private TimeUnit timeUnit;
+
+    public HistogramFacetRequest(String name) {
+        super(name);
+    }
+
+    public void setField(String field) {
+        this.field = field;
+    }
+
+    public void setInterval(long interval) {
+        this.interval = interval;
+    }
+
+    public void setTimeUnit(TimeUnit timeUnit) {
+        this.timeUnit = timeUnit;
+    }
+
+    public FacetBuilder getFacet() {
+        Assert.notNull(getName(), "Facet name can't be a null !!!");
+        Assert.isTrue(StringUtils.isNotBlank(field), "Please select field on which to build the facet !!!");
+        Assert.isTrue(interval > 0, "Please provide interval as positive value greater them zero !!!");
+
+        HistogramFacetBuilder builder = FacetBuilders.histogramFacet(getName());
+        builder.field(field);
+
+        if (timeUnit != null) {
+            builder.interval(interval, timeUnit);
+        } else {
+            builder.interval(interval);
+        }
+
+        return builder;
+    }
+}

src/main/java/org/springframework/data/elasticsearch/core/facet/request/HistogramFacetRequestBuilder.java

@@ -0,0 +1,41 @@
+package org.springframework.data.elasticsearch.core.facet.request;
+
+import org.springframework.data.elasticsearch.core.facet.FacetRequest;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * @author Artur Konczak
+ */
+public class HistogramFacetRequestBuilder {
+
+    HistogramFacetRequest result;
+
+    public HistogramFacetRequestBuilder(String name) {
+        result = new HistogramFacetRequest(name);
+    }
+
+    public HistogramFacetRequestBuilder field(String field) {
+        result.setField(field);
+        return this;
+    }
+
+    public HistogramFacetRequestBuilder interval(long interval) {
+        result.setInterval(interval);
+        return this;
+    }
+
+    public HistogramFacetRequestBuilder timeUnit(TimeUnit timeUnit) {
+        result.setTimeUnit(timeUnit);
+        return this;
+    }
+
+    public FacetRequest build() {
+        return result;
+    }
+
+    public HistogramFacetRequestBuilder applyQueryFilter() {
+        result.setApplyQueryFilter(true);
+        return this;
+    }
+}

src/main/java/org/springframework/data/elasticsearch/core/facet/result/HistogramResult.java

@@ -0,0 +1,24 @@
+package org.springframework.data.elasticsearch.core.facet.result;
+
+import org.springframework.data.elasticsearch.core.facet.AbstactFacetResult;
+import org.springframework.data.elasticsearch.core.facet.FacetType;
+
+import java.util.List;
+
+/**
+ * @author Artur Konczak
+ */
+public class HistogramResult extends AbstactFacetResult {
+
+    private List<IntervalUnit> terms;
+
+    public HistogramResult(String name, List<IntervalUnit> terms) {
+        super(name, FacetType.term);
+        this.terms = terms;
+    }
+
+    public List<IntervalUnit> getIntervalUnit() {
+        return terms;
+    }
+
+}

src/main/java/org/springframework/data/elasticsearch/core/facet/result/IntervalUnit.java

@@ -0,0 +1,76 @@
+package org.springframework.data.elasticsearch.core.facet.result;
+
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
+/**
+ * Single term
+ *
+ * @author Rizwan Idrees
+ * @author Mohsin Husen
+ * @author Artur Konczak
+ * @author Jonathan Yan
+ */
+public class IntervalUnit {
+
+    private static final SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm");
+
+    long key;
+    long count;
+    long totalCount;
+    double total;
+    double mean;
+    double min;
+    double max;
+
+    public IntervalUnit(long key, long count, long totalCount, double total, double mean, double min, double max) {
+        this.key = key;
+        this.count = count;
+        this.totalCount = totalCount;
+        this.total = total;
+        this.mean = mean;
+        this.min = min;
+        this.max = max;
+    }
+
+    public long getKey() {
+        return key;
+    }
+
+    public long getCount() {
+        return count;
+    }
+
+    public long getTotalCount() {
+        return totalCount;
+    }
+
+    public double getTotal() {
+        return total;
+    }
+
+    public double getMean() {
+        return mean;
+    }
+
+    public double getMin() {
+        return min;
+    }
+
+    public double getMax() {
+        return max;
+    }
+
+    @Override
+    public String toString() {
+        return "IntervalUnit{" +
+                "key=" + format.format(new Date(key)) +
+                ", count=" + count +
+                ", totalCount=" + totalCount +
+                ", total=" + total +
+                ", mean=" + mean +
+                ", min=" + min +
+                ", max=" + max +
+                '}';
+    }
+}