improve handling of missing message files

Bukkit/src/main/java/com/plotsquared/bukkit/BukkitPlatform.java

@@ -732,6 +732,11 @@ public final class BukkitPlatform extends JavaPlugin implements Listener, PlotPl
         this.getServer().getPluginManager().disablePlugin(this);
     }
 
+    @Override
+    public void shutdownServer() {
+        getServer().shutdown();
+    }
+
     private void registerCommands() {
         final BukkitCommand bukkitCommand = new BukkitCommand();
         final PluginCommand plotCommand = getCommand("plots");

Core/src/main/java/com/plotsquared/core/PlotPlatform.java

@@ -75,6 +75,11 @@ public interface PlotPlatform<P> extends LocaleHolder {
      */
     void shutdown();
 
+    /**
+     * Completely shuts down the server.
+     */
+    void shutdownServer();
+
     /**
      * Get the name of the plugin
      *

Core/src/main/java/com/plotsquared/core/PlotSquared.java

@@ -197,6 +197,9 @@ public class PlotSquared {
             this.loadCaptionMap();
         } catch (final Exception e) {
             LOGGER.error("Failed to load caption map", e);
+            LOGGER.error("Shutting down server to prevent further issues");
+            this.platform.shutdownServer();
+            throw new RuntimeException("Abort loading PlotSquared");
         }
 
         // Setup the global flag container
@@ -267,7 +270,7 @@ public class PlotSquared {
             captionMap = this.captionLoader.loadAll(this.platform.getDirectory().toPath().resolve("lang"));
         } else {
             String fileName = "messages_" + Settings.Enabled_Components.DEFAULT_LOCALE + ".json";
-            captionMap = this.captionLoader.loadSingle(this.platform.getDirectory().toPath().resolve("lang").resolve(fileName));
+            captionMap = this.captionLoader.loadOrCreateSingle(this.platform.getDirectory().toPath().resolve("lang").resolve(fileName));
         }
         this.captionMaps.put(TranslatableCaption.DEFAULT_NAMESPACE, captionMap);
         LOGGER.info(

Core/src/main/java/com/plotsquared/core/configuration/caption/load/CaptionLoader.java

@@ -191,12 +191,14 @@ public final class CaptionLoader {
     /**
      * Load a message file into a new CaptionMap. The file name must match
      * the pattern {@code messages_<locale>.json} where {@code <locale>}
-     * is a valid {@link Locale} string.
+     * is a valid {@link Locale} string. Note that this method does not attempt to
+     * create a new file.
      *
      * @param file The file to load
      * @return A new CaptionMap containing the loaded messages
      * @throws IOException              if the file couldn't be accessed or read successfully.
      * @throws IllegalArgumentException if the file name doesn't match the specified format.
+     * @see #loadOrCreateSingle(Path)
      */
     public @NonNull CaptionMap loadSingle(final @NonNull Path file) throws IOException {
         final Locale locale = this.localeExtractor.apply(file);
@@ -205,15 +207,42 @@ public final class CaptionLoader {
             if (patch(map, locale)) {
                 save(file, map); // update the file using the modified map
             }
-            return new LocalizedCaptionMap(locale, map.entrySet().stream()
+            return new LocalizedCaptionMap(locale, mapToCaptions(map));
-                    .collect(Collectors.toMap(
-                                    entry -> TranslatableCaption.of(this.namespace, entry.getKey()),
-                                    Map.Entry::getValue
-                            )
-                    ));
         }
     }
 
+    /**
+     * Load a message file into a new CaptionMap. The file name must match
+     * the pattern {@code messages_<locale>.json} where {@code <locale>}
+     * is a valid {@link Locale} string. If no file exists at the given path, this method will
+     * attempt to create one and fill it with default values.
+     *
+     * @param file The file to load
+     * @return A new CaptionMap containing the loaded messages
+     * @throws IOException              if the file couldn't be accessed or read successfully.
+     * @throws IllegalArgumentException if the file name doesn't match the specified format.
+     * @see #loadOrCreateSingle(Path)
+     */
+    public @NonNull CaptionMap loadOrCreateSingle(final @NonNull Path file) throws IOException {
+        final Locale locale = this.localeExtractor.apply(file);
+        if (!Files.exists(file) ) {
+            Map<String, String> map = new LinkedHashMap<>();
+            patch(map, locale);
+            save(file, map);
+            return new LocalizedCaptionMap(locale, mapToCaptions(map));
+        } else {
+            return loadSingle(file);
+        }
+    }
+
+    private @NonNull Map<TranslatableCaption, String> mapToCaptions(Map<String, String> map) {
+        return map.entrySet().stream().collect(
+                Collectors.toMap(
+                        entry -> TranslatableCaption.of(this.namespace, entry.getKey()),
+                        Map.Entry::getValue
+                ));
+    }
+
     /**
      * Add missing entries to the given map.
      * Entries are missing if the key exists in {@link #defaultLocale} but isn't present