DATACASS-549 - Add Criteria.ne(…) and Criteria.isNotNull() operators.

spring-data-cassandra/src/main/java/org/springframework/data/cassandra/core/StatementFactory.java

@@ -65,14 +65,8 @@ import com.google.common.primitives.Ints;
  *
  * @author Mark Paluch
  * @author John Blum
- * @see org.springframework.data.cassandra.core.query.Query
- * @see org.springframework.data.cassandra.core.query.Update
- * @see com.datastax.driver.core.querybuilder.Assignment
- * @see com.datastax.driver.core.querybuilder.Clause
- * @see com.datastax.driver.core.querybuilder.Delete
- * @see com.datastax.driver.core.querybuilder.Ordering
- * @see com.datastax.driver.core.querybuilder.QueryBuilder
- * @see com.datastax.driver.core.querybuilder.Select
+ * @see Query
+ * @see Update
  * @since 2.0
  */
 public class StatementFactory {
@@ -500,6 +494,9 @@ public class StatementFactory {
 			case "=":
 				return QueryBuilder.eq(columnName, predicate.getValue());
 
+			case "!=":
+				return QueryBuilder.ne(columnName, predicate.getValue());
+
 			case ">":
 				return QueryBuilder.gt(columnName, predicate.getValue());
 
@@ -527,6 +524,9 @@ public class StatementFactory {
 			case "LIKE":
 				return QueryBuilder.like(columnName, predicate.getValue());
 
+			case "IS NOT NULL":
+				return QueryBuilder.notNull(columnName);
+
 			case "CONTAINS":
 				Assert.state(predicate.getValue() != null,
 						() -> String.format("CONTAINS value for column %s is null", columnName));

spring-data-cassandra/src/main/java/org/springframework/data/cassandra/core/query/Criteria.java

@@ -92,6 +92,31 @@ public class Criteria implements CriteriaDefinition {
 		return this;
 	}
 
+	/**
+	 * Create a criterion using the {@literal !=} operator.
+	 *
+	 * @param value the value to match against, may be {@literal null}.
+	 * @return {@literal this} {@link Criteria} object.
+	 * @since 2.1
+	 */
+	public CriteriaDefinition ne(@Nullable Object value) {
+
+		this.predicate = new Predicate(Operators.NE, value);
+		return this;
+	}
+
+	/**
+	 * Create a criterion using the {@literal IS NOT NULL} operator.
+	 *
+	 * @return {@literal this} {@link Criteria} object.
+	 * @since 2.1
+	 */
+	public CriteriaDefinition isNotNull() {
+
+		this.predicate = new Predicate(Operators.IS_NOT_NULL, null);
+		return this;
+	}
+
 	/**
 	 * Create a criterion using the {@literal >} operator.
 	 *

spring-data-cassandra/src/main/java/org/springframework/data/cassandra/core/query/CriteriaDefinition.java

@@ -93,6 +93,19 @@ public interface CriteriaDefinition {
 		 * @return the String representation of the operator.
 		 */
 		String toString();
+
+		/**
+		 * Render to a CQL-like representation. Rendering does not apply conversion via
+		 * {@link com.datastax.driver.core.CodecRegistry} therefore this output is an approximation towards CQL and not
+		 * necessarily valid CQL.
+		 *
+		 * @param value optional predicate value, can be {@literal null}.
+		 * @return A CQL-like representation.
+		 * @since 2.1
+		 */
+		default String toCql(@Nullable Object value) {
+			return String.format("%s %s", toString(), value);
+		}
 	}
 
 	/**
@@ -103,6 +116,21 @@ public interface CriteriaDefinition {
 		CONTAINS("CONTAINS"),
 		CONTAINS_KEY("CONTAINS KEY"),
 		EQ("="),
+
+		/**
+		 * @since 2.1
+		 */
+		NE("!="),
+
+		/**
+		 * @since 2.1
+		 */
+		IS_NOT_NULL("IS NOT NULL") {
+			@Override
+			public String toCql(@Nullable Object value) {
+				return toString();
+			}
+		},
 		GT(">"),
 		GTE(">="),
 		LT("<"),

spring-data-cassandra/src/main/java/org/springframework/data/cassandra/core/query/SerializationUtils.java

@@ -57,9 +57,8 @@ abstract class SerializationUtils {
 
 		CriteriaDefinition.Predicate predicate = criteria.getPredicate();
 
-		return serialize(criteria.getColumnName(), predicate.getOperator())
-				.append(serializeToCqlSafely(predicate.getValue())).toString();
-
+		return String.format("%s %s", criteria.getColumnName(),
+				predicate.getOperator().toCql(serializeToCqlSafely(predicate.getValue())));
 	}
 
 	/**

spring-data-cassandra/src/test/java/org/springframework/data/cassandra/core/StatementFactoryUnitTests.java

@@ -15,14 +15,13 @@
  */
 package org.springframework.data.cassandra.core;
 
-import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.*;
 
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
 import org.junit.Test;
-
 import org.springframework.data.annotation.Id;
 import org.springframework.data.cassandra.core.convert.CassandraConverter;
 import org.springframework.data.cassandra.core.convert.MappingCassandraConverter;
@@ -73,6 +72,26 @@ public class StatementFactoryUnitTests {
 		assertThat(select.toString()).isEqualTo("SELECT age FROM group WHERE foo='bar';");
 	}
 
+	@Test // DATACASS-549
+	public void shouldMapSelectQueryNotEquals() {
+
+		Query query = Query.query(Criteria.where("foo").ne("bar")).columns(Columns.from("age"));
+
+		Statement select = statementFactory.select(query, groupEntity);
+
+		assertThat(select.toString()).isEqualTo("SELECT age FROM group WHERE foo!='bar';");
+	}
+
+	@Test // DATACASS-549
+	public void shouldMapSelectQueryIsNotNull() {
+
+		Query query = Query.query(Criteria.where("foo").isNotNull()).columns(Columns.from("age"));
+
+		Statement select = statementFactory.select(query, groupEntity);
+
+		assertThat(select.toString()).isEqualTo("SELECT age FROM group WHERE foo IS NOT NULL;");
+	}
+
 	@Test // DATACASS-343
 	public void shouldMapSelectQueryWithTtlColumns() {
 

spring-data-cassandra/src/test/java/org/springframework/data/cassandra/core/query/CriteriaUnitTests.java

@@ -38,6 +38,22 @@ public class CriteriaUnitTests {
 		assertThat(serializeToCqlSafely(criteria)).isEqualTo("foo = 'bar'");
 	}
 
+	@Test // DATACASS-549
+	public void shouldCreateIsNotEqualTo() {
+
+		CriteriaDefinition criteria = Criteria.where("foo").ne("bar");
+
+		assertThat(serializeToCqlSafely(criteria)).isEqualTo("foo != 'bar'");
+	}
+
+	@Test // DATACASS-549
+	public void shouldCreateIsNotNull() {
+
+		CriteriaDefinition criteria = Criteria.where("foo").isNotNull();
+
+		assertThat(serializeToCqlSafely(criteria)).isEqualTo("foo IS NOT NULL");
+	}
+
 	@Test // DATACASS-343
 	public void shouldCreateIsGreater() {