DRILL-4346: Handle NumberFormatException when casting empty string to int in hbase/maprdb

- Made replacing of functions casting for nullable input varbinary and var16char types are working (in CastFunctions.java setting 'drill.exec.functions.cast_empty_string_to_null = true' didn't work);
- Added new generated classes for casting varbinary and var16char to int (CastEmptyStringVarTypesToNullableNumeric template and Casts.tdd data);
- Created a test (in TestHBaseQueries.java) for checking an empty string to integer casting in maprdb/hbase table;
- Small design changes according to comments in review (import statements, prefixes ...).

This closes #384

3 files changed, 49 insertions, 1 deletions

diff --git a/contrib/storage-hbase/src/test/java/org/apache/drill/hbase/HBaseTestsSuite.java b/contrib/storage-hbase/src/test/java/org/apache/drill/hbase/HBaseTestsSuite.java
index fe1126592..8f59b676c 100644
--- a/contrib/storage-hbase/src/test/java/org/apache/drill/hbase/HBaseTestsSuite.java
+++ b/contrib/storage-hbase/src/test/java/org/apache/drill/hbase/HBaseTestsSuite.java
@@ -61,6 +61,7 @@ public class HBaseTestsSuite {
   protected static final String TEST_TABLE_FLOAT_OB_DESC = "TestTableFloatOBDesc";
   protected static final String TEST_TABLE_BIGINT_OB_DESC = "TestTableBigIntOBDesc";
   protected static final String TEST_TABLE_INT_OB_DESC = "TestTableIntOBDesc";
+  protected static final String TEST_TABLE_NULL_STR = "TestTableNullStr";
 
   private static Configuration conf;
 
@@ -159,7 +160,8 @@ public class HBaseTestsSuite {
            && admin.tableExists(TEST_TABLE_DOUBLE_OB_DESC)
            && admin.tableExists(TEST_TABLE_FLOAT_OB_DESC)
            && admin.tableExists(TEST_TABLE_BIGINT_OB_DESC)
-           && admin.tableExists(TEST_TABLE_INT_OB_DESC);
+           && admin.tableExists(TEST_TABLE_INT_OB_DESC)
+           && admin.tableExists(TEST_TABLE_NULL_STR);
   }
 
   private static void createTestTables() throws Exception {
@@ -183,6 +185,7 @@ public class HBaseTestsSuite {
     TestTableGenerator.generateHBaseDatasetFloatOBDesc(admin, TEST_TABLE_FLOAT_OB_DESC, 1);
     TestTableGenerator.generateHBaseDatasetBigIntOBDesc(admin, TEST_TABLE_BIGINT_OB_DESC, 1);
     TestTableGenerator.generateHBaseDatasetIntOBDesc(admin, TEST_TABLE_INT_OB_DESC, 1);
+    TestTableGenerator.generateHBaseDatasetNullStr(admin, TEST_TABLE_NULL_STR, 1);
   }
 
   private static void cleanupTestTables() throws IOException {
@@ -212,6 +215,8 @@ public class HBaseTestsSuite {
     admin.deleteTable(TEST_TABLE_BIGINT_OB_DESC);
     admin.disableTable(TEST_TABLE_INT_OB_DESC);
     admin.deleteTable(TEST_TABLE_INT_OB_DESC);
+    admin.disableTable(TEST_TABLE_NULL_STR);
+    admin.deleteTable(TEST_TABLE_NULL_STR);
   }
 
   public static int getZookeeperPort() {
diff --git a/contrib/storage-hbase/src/test/java/org/apache/drill/hbase/TestHBaseQueries.java b/contrib/storage-hbase/src/test/java/org/apache/drill/hbase/TestHBaseQueries.java
index 3f412c7c5..ce7d585f8 100644
--- a/contrib/storage-hbase/src/test/java/org/apache/drill/hbase/TestHBaseQueries.java
+++ b/contrib/storage-hbase/src/test/java/org/apache/drill/hbase/TestHBaseQueries.java
@@ -18,7 +18,9 @@
 package org.apache.drill.hbase;
 
 import java.util.Arrays;
+import java.util.List;
 
+import org.apache.drill.exec.rpc.user.QueryDataBatch;
 import org.apache.hadoop.hbase.HColumnDescriptor;
 import org.apache.hadoop.hbase.HTableDescriptor;
 import org.apache.hadoop.hbase.client.HBaseAdmin;
@@ -90,4 +92,18 @@ public class TestHBaseQueries extends BaseHBaseTest {
       } catch (Exception e) { } // ignore
     }
   }
+  @Test
+  public void testCastEmptyStrings() throws Exception {
+    try {
+        test("alter system set `drill.exec.functions.cast_empty_string_to_null` = true;");
+        setColumnWidths(new int[] {5, 4});
+        List<QueryDataBatch> resultList = runHBaseSQLlWithResults("SELECT row_key,\n"
+            + " CAST(t.f.c1 as INT) c1, CAST(t.f.c2 as BIGINT) c2, CAST(t.f.c3 as INT) c3,\n"
+            + " CAST(t.f.c4 as INT) c4 FROM hbase.TestTableNullStr t where row_key='a1'");
+        printResult(resultList);
+    }
+    finally {
+        test("alter system reset `drill.exec.functions.cast_empty_string_to_null`;");
+    }
+  }
 }
diff --git a/contrib/storage-hbase/src/test/java/org/apache/drill/hbase/TestTableGenerator.java b/contrib/storage-hbase/src/test/java/org/apache/drill/hbase/TestTableGenerator.java
index 77e9d6412..f4f3e933d 100644
--- a/contrib/storage-hbase/src/test/java/org/apache/drill/hbase/TestTableGenerator.java
+++ b/contrib/storage-hbase/src/test/java/org/apache/drill/hbase/TestTableGenerator.java
@@ -610,4 +610,31 @@ public class TestTableGenerator {
 
     admin.flush(tableName);
   }
+
+  public static void generateHBaseDatasetNullStr(HBaseAdmin admin, String tableName, int numberRegions) throws Exception {
+    if (admin.tableExists(tableName)) {
+      admin.disableTable(tableName);
+      admin.deleteTable(tableName);
+    }
+
+    HTableDescriptor desc = new HTableDescriptor(tableName);
+    desc.addFamily(new HColumnDescriptor("f"));
+    if (numberRegions > 1) {
+      admin.createTable(desc, Arrays.copyOfRange(SPLIT_KEYS, 0, numberRegions-1));
+    } else {
+      admin.createTable(desc);
+    }
+
+    HTable table = new HTable(admin.getConfiguration(), tableName);
+
+    Put p = new Put("a1".getBytes());
+    p.add("f".getBytes(), "c1".getBytes(), "".getBytes());
+    p.add("f".getBytes(), "c2".getBytes(), "".getBytes());
+    p.add("f".getBytes(), "c3".getBytes(), "5".getBytes());
+    p.add("f".getBytes(), "c4".getBytes(), "".getBytes());
+    table.put(p);
+
+    table.flushCommits();
+    table.close();
+  }
 }