[SPARK-6912] [SQL] Throw an AnalysisException when unsupported Java Map<K,V> types used in Hive UDF

To make UDF developers understood, throw an exception when unsupported Map<K,V> types used in Hive UDF. This fix is the same with #7248.

Author: Takeshi YAMAMURO <linguin.m.s@gmail.com>

Closes #7257 from maropu/ThrowExceptionWhenMapUsed and squashes the following commits:

916099a [Takeshi YAMAMURO] Fix style errors
7886dcc [Takeshi YAMAMURO] Throw an exception when Map<> used in Hive UDF

sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveInspectors.scala

@@ -226,6 +226,12 @@ private[hive] trait HiveInspectors {
         "List type in java is unsupported because " +
         "JVM type erasure makes spark fail to catch a component type in List<>")
 
+    // java map type unsupported
+    case c: Class[_] if c == classOf[java.util.Map[_, _]] =>
+      throw new AnalysisException(
+        "Map type in java is unsupported because " +
+        "JVM type erasure makes spark fail to catch key and value types in Map<>")
+
     case c => throw new AnalysisException(s"Unsupported java type $c")
   }
 

sql/hive/src/test/java/org/apache/spark/sql/hive/execution/UDFToIntIntMap.java

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.hive.execution;
+
+import org.apache.hadoop.hive.ql.exec.UDF;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class UDFToIntIntMap extends UDF {
+    public Map<Integer, Integer> evaluate(Object o) {
+        return new HashMap<Integer, Integer>() {
+            {
+                put(1, 1);
+                put(2, 1);
+                put(3, 1);
+            }
+        };
+    }
+}

sql/hive/src/test/java/org/apache/spark/sql/hive/execution/UDFToStringIntMap.java

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.hive.execution;
+
+import org.apache.hadoop.hive.ql.exec.UDF;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class UDFToStringIntMap extends UDF {
+    public Map<String, Integer> evaluate(Object o) {
+        return new HashMap<String, Integer>() {
+            {
+                put("key1", 1);
+                put("key2", 2);
+                put("key3", 3);
+            }
+        };
+    }
+}

sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveUDFSuite.scala

@@ -163,6 +163,38 @@ class HiveUDFSuite extends QueryTest {
     TestHive.reset()
   }
 
+  test("UDFToStringIntMap") {
+    val testData = TestHive.sparkContext.parallelize(StringCaseClass("") :: Nil).toDF()
+    testData.registerTempTable("inputTable")
+
+    sql(s"CREATE TEMPORARY FUNCTION testUDFToStringIntMap " +
+      s"AS '${classOf[UDFToStringIntMap].getName}'")
+    val errMsg = intercept[AnalysisException] {
+      sql("SELECT testUDFToStringIntMap(s) FROM inputTable")
+    }
+    assert(errMsg.getMessage === "Map type in java is unsupported because " +
+      "JVM type erasure makes spark fail to catch key and value types in Map<>;")
+
+    sql("DROP TEMPORARY FUNCTION IF EXISTS testUDFToStringIntMap")
+    TestHive.reset()
+  }
+
+  test("UDFToIntIntMap") {
+    val testData = TestHive.sparkContext.parallelize(StringCaseClass("") :: Nil).toDF()
+    testData.registerTempTable("inputTable")
+
+    sql(s"CREATE TEMPORARY FUNCTION testUDFToIntIntMap " +
+      s"AS '${classOf[UDFToIntIntMap].getName}'")
+    val errMsg = intercept[AnalysisException] {
+      sql("SELECT testUDFToIntIntMap(s) FROM inputTable")
+    }
+    assert(errMsg.getMessage === "Map type in java is unsupported because " +
+      "JVM type erasure makes spark fail to catch key and value types in Map<>;")
+
+    sql("DROP TEMPORARY FUNCTION IF EXISTS testUDFToIntIntMap")
+    TestHive.reset()
+  }
+
   test("UDFListListInt") {
     val testData = TestHive.sparkContext.parallelize(
       ListListIntCaseClass(Nil) ::