[SPARK-4676] [SQL] JavaSchemaRDD.schema may throw NullType MatchError if sql has null

Author: YanTangZhai

sql/core/src/test/scala/org/apache/spark/sql/api/java/JavaSQLSuite.scala

@@ -68,21 +68,21 @@ class JavaSQLSuite extends FunSuite {
     javaSqlCtx.sql("SELECT * FROM people").collect()
   }
 
-	test("schema with null from JavaBeans") {
-	  val person = new PersonBean
-		person.setName("Michael")
-		person.setAge(29)
-
-		val rdd = javaCtx.parallelize(person :: Nil)
-		val schemaRDD = javaSqlCtx.applySchema(rdd, classOf[PersonBean])
-
-		schemaRDD.registerTempTable("people")
-		val nullRDD = javaSqlCtx.sql("SELECT null FROM people")
-		val structFields = nullRDD.schema.getFields()
-		assert(structFields.size == 1)
-		assert(structFields(0).getDataType().isInstanceOf[NullType])
-		assert(nullRDD.collect.head.row === Seq(null))
-	}
+  test("schema with null from JavaBeans") {
+    val person = new PersonBean
+    person.setName("Michael")
+    person.setAge(29)
+
+    val rdd = javaCtx.parallelize(person :: Nil)
+    val schemaRDD = javaSqlCtx.applySchema(rdd, classOf[PersonBean])
+
+    schemaRDD.registerTempTable("people")
+    val nullRDD = javaSqlCtx.sql("SELECT null FROM people")
+    val structFields = nullRDD.schema.getFields()
+    assert(structFields.size == 1)
+    assert(structFields(0).getDataType().isInstanceOf[NullType])
+    assert(nullRDD.collect.head.row === Seq(null))
+  }
 
   test("all types in JavaBeans") {
     val bean = new AllTypesBean