[PATCH] Improve importer start

[Wald Commits]

# HG changeset patch
# User Tom Gottfried <tom at intevation.de>
# Date 1657185548 -7200
#      Thu Jul 07 11:19:08 2022 +0200
# Branch 3.2.x
# Node ID 7e767c0c9a6dbb386d9746a3d01fa87bbf245538
# Parent  ca1319d5816d91624d8889ecaff10c98eb252ba0
Improve importer start

_ Consider no given info gew files as error instead of starting to
  process an empty list.
_ Reduce code duplication.

diff -r ca1319d5816d -r 7e767c0c9a6d backend/src/main/java/org/dive4elements/river/importer/Importer.java
--- a/backend/src/main/java/org/dive4elements/river/importer/Importer.java	Thu Apr 28 18:02:21 2022 +0200
+++ b/backend/src/main/java/org/dive4elements/river/importer/Importer.java	Thu Jul 07 11:19:08 2022 +0200
@@ -17,6 +17,8 @@
 import java.io.File;
 import java.io.IOException;
 
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -133,6 +135,18 @@
     /** Starting point for importing river data. */
     public static void main(String [] args) {
 
+        // Take paths of GEW files from arguments and system property
+        List<String> gews = new ArrayList<>(Arrays.asList(args));
+        String gewProperty = Config.INSTANCE.getInfoGewFile();
+        if (gewProperty != null && gewProperty.length() > 0) {
+            gews.add(gewProperty);
+        }
+
+        if (gews.isEmpty()) {
+            log.error("No info gew files given");
+            System.exit(1);
+        }
+
         InfoGewParser infoGewParser = new InfoGewParser(
             getAnnotationClassifier());
 
@@ -140,24 +154,7 @@
 
         File bwastrFile = null;
 
-        for (String gew: args) {
-            log.info("parsing info gew file: " + gew);
-            File gewFile = new File(gew);
-            if (bwastrFile == null) {
-                bwastrFile = new File(
-                    gewFile.getParentFile(), BWASTR_ID_CSV_FILE);
-            }
-            try {
-                infoGewParser.parse(gewFile);
-            }
-            catch (IOException ioe) {
-                log.error("error while parsing gew: " + gew, ioe);
-                System.exit(1);
-            }
-        }
-
-        String gew = Config.INSTANCE.getInfoGewFile();
-        if (gew != null && gew.length() > 0) {
+        for (String gew: gews) {
             log.info("parsing info gew file: " + gew);
             File gewFile = new File(gew);
             if (bwastrFile == null) {