Fix plugin loading on paper (#27)

plugin/src/main/java/de/epiceric/shopchest/ShopChest.java

@@ -419,7 +419,7 @@ public class ShopChest extends JavaPlugin {
         getServer().getPluginManager().registerEvents(new ChestProtectListener(this), this);
         getServer().getPluginManager().registerEvents(new CreativeModeListener(this), this);
 
-        if (!Utils.getServerVersion().equals("v1_8_R1")) {
+        if (Utils.getMajorVersion() != 8 || Utils.getRevision() != 1) {
             getServer().getPluginManager().registerEvents(new BlockExplodeListener(this), this);
         }
 

plugin/src/main/java/de/epiceric/shopchest/nms/PlatformLoader.java

@@ -1,12 +1,13 @@
 package de.epiceric.shopchest.nms;
 
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+
+import org.bukkit.Bukkit;
+
 import de.epiceric.shopchest.nms.reflection.PlatformImpl;
 import de.epiceric.shopchest.nms.reflection.ShopChestDebug;
 import de.epiceric.shopchest.utils.Utils;
-import org.bukkit.Bukkit;
-
-import java.lang.reflect.Field;
-import java.lang.reflect.Method;
 
 public class PlatformLoader {
 
@@ -17,19 +18,25 @@ public class PlatformLoader {
     }
 
     public Platform loadPlatform() {
-        final String nmsVersion = Utils.getServerVersion();
+        Platform platform = null;
-
+        if (Utils.getMajorVersion() < 17) {
-        Platform platform = getReflectionPlatform(nmsVersion);
+            final String bukkitPackageVersion = getBukkitPackageVersion();
-        if (platform != null) {
+            platform = getReflectionPlatform(bukkitPackageVersion);
+            if (platform == null) {
+                throw new RuntimeException(
+                        "Could not retrieve the mappings version. The server version might be too old ("
+                                + bukkitPackageVersion + ").");
+            }
             return platform;
         }
         final String mappingsVersion = getMappingsVersion();
         if (mappingsVersion == null) {
-            throw new RuntimeException("Could not retrieve the mappings version. The server version might be too old (" + nmsVersion + ").");
+            throw new RuntimeException("Could not get any information about the server version");
         }
         platform = getSpecificPlatform(mappingsVersion);
         if (platform == null) {
-            throw new RuntimeException("Server version not officially supported. Version: '" + nmsVersion + "', Mappings : " + "'" + mappingsVersion + "'");
+            throw new RuntimeException(
+                    "Server version not officially supported. Mappings : " + "'" + mappingsVersion + "'");
         }
         return platform;
     }
@@ -57,9 +64,15 @@ public class PlatformLoader {
         }
     }
 
+    private String getBukkitPackageVersion() {
+        final String packageName = Bukkit.getServer().getClass().getPackage().getName();
+        return packageName.substring(packageName.lastIndexOf(".") + 1);
+    }
+
     private String getMappingsVersion() {
         try {
-            final String craftMagicNumbersClassName = Bukkit.getServer().getClass().getPackage().getName() + ".util.CraftMagicNumbers";
+            final String craftMagicNumbersClassName = Bukkit.getServer().getClass().getPackage().getName()
+                    + ".util.CraftMagicNumbers";
             final Class<?> craftMagicNumbersClass = Class.forName(craftMagicNumbersClassName);
             final Method method = craftMagicNumbersClass.getDeclaredMethod("getMappingsVersion");
             method.setAccessible(true);

plugin/src/main/java/de/epiceric/shopchest/utils/Utils.java

@@ -311,27 +311,69 @@ public class Utils {
         );
     }
 
+    private final static int majorVersion;
+    private final static int revision;
+
+    static {
+        String rawMajorVersion = null;
+        try {
+            final String bukkitVersion = Bukkit.getServer().getBukkitVersion();
+            final String[] minecraftVersion = bukkitVersion.substring(0, bukkitVersion.indexOf('-')).split("\\.");
+            rawMajorVersion = minecraftVersion[1];
+        } catch (Exception e) {
+            try {
+                final String packageName = Bukkit.getServer().getClass().getPackage().getName();
+                final String serverVersion = packageName.substring(packageName.lastIndexOf('.') + 1);
+                rawMajorVersion = serverVersion.split("_")[1];
+            } catch (Exception ex) {
+                if (rawMajorVersion == null) {
+                    throw new RuntimeException("Could not load major version");
+                }
+            }
+        }
+        int parsedMajorVersion = -1;
+        try {
+            parsedMajorVersion = Integer.valueOf(rawMajorVersion);
+        } catch (Exception e) {
+            throw new RuntimeException("Could not parse major version");
+        }
+        int parsedRevision = 0;
+        if (parsedMajorVersion < 17) {
+            try {
+                final String packageName = Bukkit.getServer().getClass().getPackage().getName();
+                final String serverVersion = packageName.substring(packageName.lastIndexOf('.') + 1);
+                final String rawRevision = serverVersion.substring(serverVersion.length() - 1);
+                parsedRevision = Integer.valueOf(rawRevision);
+            } catch (Exception e) {}
+        }
+        majorVersion = parsedMajorVersion;
+        revision = parsedRevision;
+    }
+
     /**
      * @return The current server version with revision number (e.g. v1_9_R2, v1_10_R1)
      */
-    public static String getServerVersion() {
+    private static String getServerVersion() {
+        /*
         String packageName = Bukkit.getServer().getClass().getPackage().getName();
 
         return packageName.substring(packageName.lastIndexOf('.') + 1);
+        */
+        return "";
     }
 
     /**
      * @return The revision of the current server version (e.g. <i>2</i> for v1_9_R2, <i>1</i> for v1_10_R1)
      */
     public static int getRevision() {
-        return Integer.parseInt(getServerVersion().substring(getServerVersion().length() - 1));
+        return revision;
     }
 
     /**
      * @return The major version of the server (e.g. <i>9</i> for 1.9.2, <i>10</i> for 1.10)
      */
     public static int getMajorVersion() {
-        return Integer.parseInt(getServerVersion().split("_")[1]);
+        return majorVersion;
     }
 
     /**