[SPARK-12932][JAVA API] improved error message for java type inference failure

Author: Andy Grove <andygrove73@gmail.com>

Closes #10865 from andygrove/SPARK-12932.

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/JavaTypeInference.scala

@@ -406,7 +406,8 @@ object JavaTypeInference {
               expressions.Literal(fieldName) :: extractorFor(fieldValue, fieldType) :: Nil
             })
           } else {
-            throw new UnsupportedOperationException(s"no encoder found for ${other.getName}")
+            throw new UnsupportedOperationException(
+              s"Cannot infer type for class ${other.getName} because it is not bean-compliant")
           }
       }
     }