#642 Fix the case when an exception message is null.

Author: yruslan

pramen/core/src/main/scala/za/co/absa/pramen/core/metastore/peristence/MetastorePersistenceRaw.scala

@@ -96,7 +96,7 @@ class MetastorePersistenceRaw(path: String,
         copiedSize += fsSrc.getContentSummary(srcPath).getLength
         fsUtilsTrg.copyFileWithRetry(srcPath, trgPath) match {
           case None => Seq.empty[String]
-          case Some(ex) => Seq(ex.getMessage)
+          case Some(ex) if ex.getMessage != null => Seq(ex.getMessage)
         }
       }
     }

pramen/core/src/main/scala/za/co/absa/pramen/core/utils/FsUtils.scala

@@ -454,7 +454,7 @@ class FsUtils(conf: Configuration, pathBase: String) {
       copyFile(srcFile, dstFile, overwrite)
       None
     } catch {
-      case ex: IOException if ex.getMessage.contains("multipart upload") =>
+      case ex: IOException if Option(ex.getMessage).exists(_.toLowerCase.contains("multipart upload")) =>
         if (numberOfAttempts > 1) {
           log.warn(s"Failed to copy $srcFile to $dstFile due to multipart upload issue. Retrying in $backoffTimeSeconds seconds...", ex)
           Thread.sleep(backoffTimeSeconds * 1000)