DATASOLR-485 Add possibility to have constant score operator

src/main/java/org/springframework/data/solr/core/QueryParserBase.java

@@ -76,6 +76,7 @@ public abstract class QueryParserBase<QUERYTPYE extends SolrDataQuery> implement
 	protected static final String DELIMINATOR = ":";
 	protected static final String NOT = "-";
 	protected static final String BOOST = "^";
+	protected static final String CONSTANT_SCORE = "^=";
 
 	protected final GenericConversionService conversionService = new GenericConversionService();
 	private final List<PredicateProcessor> critieraEntryProcessors = new ArrayList<>();
@@ -228,6 +229,10 @@ protected String createQueryFragmentForCriteria(Criteria part) {
 			queryFragment.append(BOOST).append(criteria.getBoost());
 		}
 
+		if (!Float.isNaN(criteria.getScore())) {
+			queryFragment.append(CONSTANT_SCORE).append(criteria.getScore());
+		}
+
 		return queryFragment.toString();
 	}
 

src/main/java/org/springframework/data/solr/core/query/Criteria.java

@@ -37,6 +37,7 @@
  * @author Christoph Strobl
  * @author Philipp Jardas
  * @author Francisco Spaeth
+ * @author Radek Mensik
  */
 public class Criteria extends Node {
 
@@ -45,6 +46,7 @@ public class Criteria extends Node {
 
 	private @Nullable Field field;
 	private float boost = Float.NaN;
+	private float score = Float.NaN;
 
 	private Set<Predicate> predicates = new LinkedHashSet<>();
 
@@ -391,6 +393,14 @@ public Criteria boost(float boost) {
 		return this;
 	}
 
+	public Criteria constantScore(float score) {
+		if (score < 0) {
+			throw new InvalidDataAccessApiUsageException("Score must not be negative.");
+		}
+		this.score = score;
+		return this;
+	}
+
 	/**
 	 * Crates new {@link Predicate} for {@code RANGE [lowerBound TO upperBound]}
 	 * 
@@ -602,6 +612,10 @@ public float getBoost() {
 		return this.boost;
 	}
 
+	public float getScore() {
+		return score;
+	}
+
 	/**
 	 * @return unmodifiable set of all {@link Predicate}
 	 */

src/main/java/org/springframework/data/solr/core/query/Crotch.java

@@ -27,6 +27,7 @@
 
 /**
  * @author Christoph Strobl
+ * @author Radek Mensik
  * @since 1.2
  */
 public class Crotch extends Criteria {
@@ -56,6 +57,12 @@ public Crotch boost(float boost) {
 		return this;
 	}
 
+	@Override
+	public Crotch constantScore(float score) {
+		mostRecentSibling.constantScore(score);
+		return this;
+	}
+
 	@Override
 	public Crotch not() {
 

src/main/java/org/springframework/data/solr/core/query/Node.java

@@ -25,6 +25,7 @@
 
 /**
  * @author Christoph Strobl
+ * @author Radek Mensik
  * @since 1.2
  */
 public abstract class Node {
@@ -175,6 +176,8 @@ protected void setNegating(boolean negating) {
 
 	public abstract Node boost(float value);
 
+	public abstract Node constantScore(float score);
+
 	public abstract Node between(Object lowerBound, Object upperBound);
 
 	public abstract Node between(Object lowerBound, Object upperBound, boolean includeLowerBound,

src/test/java/org/springframework/data/solr/core/DefaultQueryParserTests.java

@@ -65,6 +65,7 @@
  * @author Francisco Spaeth
  * @author Petar Tahchiev
  * @author Michael Rocke
+ * @author Radek Mensik
  */
 public class DefaultQueryParserTests {
 
@@ -259,12 +260,25 @@ public void testBoostMultipleValues() {
 		assertEquals("field_1:(value_1 value_2)^2.0", queryParser.createQueryStringFromCriteria(criteria));
 	}
 
+	@Test
+	public void testScoreMultipleValues() {
+
+		Criteria criteria = new Criteria("field_1").is("value_1").is("value_2").constantScore(3f);
+		assertEquals("field_1:(value_1 value_2)^=3.0", queryParser.createQueryStringFromCriteria(criteria));
+	}
+
 	@Test
 	public void testBoostMultipleCriteriasValues() {
 		Criteria criteria = new Criteria("field_1").is("value_1").is("value_2").boost(2f).and("field_3").is("value_3");
 		assertEquals("field_1:(value_1 value_2)^2.0 AND field_3:value_3", queryParser.createQueryStringFromNode(criteria));
 	}
 
+	@Test
+	public void testScoreMultipleCriteriasValues() {
+		Criteria criteria = new Criteria("field_1").is("value_1").is("value_2").constantScore(3f).and("field_3").is("value_3");
+		assertEquals("field_1:(value_1 value_2)^=3.0 AND field_3:value_3", queryParser.createQueryStringFromNode(criteria));
+	}
+
 	@Test
 	public void testBetween() {
 

src/test/java/org/springframework/data/solr/core/query/CriteriaTests.java

@@ -38,6 +38,7 @@
  * @author Christoph Strobl
  * @author John Dorman
  * @author Philipp Jardas
+ * @author Radek Mensik
  */
 public class CriteriaTests {
 
@@ -311,6 +312,13 @@ public void testBoost() {
 		Assert.assertEquals(2f, criteria.getBoost(), 0);
 	}
 
+	@Test
+	public void testConstantScore() {
+		Criteria criteria = new Criteria("field_1").is("value_1").constantScore(4f);
+		assertPredicate(criteria.getPredicates(), 0, OperationKey.EQUALS, "value_1");
+		Assert.assertEquals(4f, criteria.getScore(), 0);
+	}
+
 	@Test
 	public void testBetween() {
 		Criteria criteria = new Criteria("field_1").between(100, 200);