implements count

Author: otaviojava

cassandra-driver/src/main/java/org/jnosql/diana/cassandra/column/DefaultCassandraColumnFamilyManager.java

@@ -22,6 +22,7 @@
 import com.datastax.driver.core.querybuilder.BuiltStatement;
 import com.datastax.driver.core.querybuilder.Insert;
 import com.datastax.driver.core.querybuilder.QueryBuilder;
+import com.datastax.driver.core.querybuilder.Select;
 import org.jnosql.diana.api.column.ColumnDeleteQuery;
 import org.jnosql.diana.api.column.ColumnEntity;
 import org.jnosql.diana.api.column.ColumnQuery;
@@ -92,6 +93,15 @@ public List<ColumnEntity> select(ColumnQuery query) {
                 .collect(Collectors.toList());
     }
 
+    @Override
+    public long count(String columnFamily) {
+        requireNonNull(columnFamily, "columnFamily is required");
+        String cql = QueryUtils.count(columnFamily, keyspace);
+        ResultSet resultSet = session.execute(cql);
+        Object object = resultSet.one().getObject(0);
+        return Number.class.cast(object).longValue();
+    }
+
     @Override
     public ColumnEntity save(ColumnEntity entity, ConsistencyLevel level) throws NullPointerException {
         requireNonNull(entity, "entity is required");

cassandra-driver/src/main/java/org/jnosql/diana/cassandra/column/DefaultCassandraColumnFamilyManagerAsync.java

@@ -219,6 +219,12 @@ public void select(ColumnQuery query, Consumer<List<ColumnEntity>> consumer)
         resultSet.addListener(executeAsync, executor);
     }
 
+    @Override
+    public void count(String columnFamily, Consumer<Long> callback) {
+        requireNonNull(columnFamily, "columnFamily is required");
+        requireNonNull(callback, "callback is required");
+    }
+
     @Override
     public void select(ColumnQuery query, ConsistencyLevel level, Consumer<List<ColumnEntity>> consumer)
             throws ExecuteAsyncQueryException, NullPointerException {

cassandra-driver/src/main/java/org/jnosql/diana/cassandra/column/QueryUtils.java

@@ -155,6 +155,10 @@ public static BuiltStatement delete(ColumnDeleteQuery query, String keySpace) {
         return where;
     }
 
+    public static String count(String columnFamily, String keyspace) {
+        return String.format("select count(*) from %s.%s", keyspace, columnFamily);
+    }
+
     private static void createClause(Optional<ColumnCondition> columnConditionOptional, List<Clause> clauses) {
         if (!columnConditionOptional.isPresent()) {
             return;
@@ -216,4 +220,5 @@ private static Object[] getIinValue(Object value) {
     }
 
 
+
 }

cassandra-driver/src/test/java/org/jnosql/diana/cassandra/column/CassandraColumnFamilyManagerTest.java

@@ -204,30 +204,30 @@ public void shouldUpdateColumns() {
 
     @Test
     public void shouldReturnErrorWhenSaveHasNullElement() {
-        assertThrows(NullPointerException.class, () ->{
-           entityManager.save((ColumnEntity) null, Duration.ofSeconds(1L), ConsistencyLevel.ALL);
+        assertThrows(NullPointerException.class, () -> {
+            entityManager.save((ColumnEntity) null, Duration.ofSeconds(1L), ConsistencyLevel.ALL);
         });
 
-        assertThrows(NullPointerException.class, () ->{
+        assertThrows(NullPointerException.class, () -> {
             entityManager.save(getColumnFamily(), null, ConsistencyLevel.ALL);
         });
 
-        assertThrows(NullPointerException.class, () ->{
+        assertThrows(NullPointerException.class, () -> {
             entityManager.save(getColumnFamily(), Duration.ofSeconds(1L), null);
         });
     }
 
     @Test
     public void shouldReturnErrorWhenSaveIterableHasNullElement() {
-        assertThrows(NullPointerException.class, () ->{
+        assertThrows(NullPointerException.class, () -> {
             entityManager.save((List<ColumnEntity>) null, Duration.ofSeconds(1L), ConsistencyLevel.ALL);
         });
 
-        assertThrows(NullPointerException.class, () ->{
+        assertThrows(NullPointerException.class, () -> {
             entityManager.save(getEntities(), null, ConsistencyLevel.ALL);
         });
 
-        assertThrows(NullPointerException.class, () ->{
+        assertThrows(NullPointerException.class, () -> {
             entityManager.save(getEntities(), Duration.ofSeconds(1L), null);
         });
     }
@@ -468,7 +468,6 @@ public void shouldSupportListUDTs() {
         entityManager.insert(entity);
     }
 
-
     @Test
     public void shouldReturnListUDT() {
         ColumnEntity entity = createEntityWithIterable();
@@ -481,6 +480,14 @@ public void shouldReturnListUDT() {
         assertTrue(names.stream().allMatch(n -> n.size() == 2));
     }
 
+    @Test
+    public void shouldCount() {
+        ColumnEntity entity = createEntityWithIterable();
+        entityManager.insert(entity);
+        long contacts = entityManager.count("contacts");
+        assertTrue(contacts > 0);
+    }
+
     private ColumnEntity createEntityWithIterable() {
         ColumnEntity entity = ColumnEntity.of("contacts");
         entity.add(Column.of("user", "otaviojava"));