Full (untested) implementation

SpigotCore_8/src/de/steamwar/sql/IDConverter.java

@@ -0,0 +1,43 @@
+package de.steamwar.sql;
+
+import org.bukkit.configuration.file.YamlConfiguration;
+
+import java.io.InputStreamReader;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+
+class IDConverter {
+    private IDConverter(){}
+
+    static Map<String, BlockTypeID> getMap(){
+        Map<String, BlockTypeID> ids = new HashMap<>();
+        YamlConfiguration legacy = YamlConfiguration.loadConfiguration(new InputStreamReader(Objects.requireNonNull(IDConverter.class.getClassLoader().getResourceAsStream("legacy.yml"))));
+        for(String blockNum : legacy.getKeys(false)){
+            String[] block = blockNum.split(":");
+            String blockString = legacy.getString(blockNum);
+            ids.put(blockString, new BlockTypeID(Integer.parseInt(block[0]), Byte.parseByte(block[1])));
+            if(blockString.contains("["))
+                ids.put(blockString.split("\\[")[0], new BlockTypeID(Integer.parseInt(block[0]), (byte)0));
+        }
+        return ids;
+    }
+
+    static class BlockTypeID{
+        private final int blockId;
+        private final byte dataId;
+
+        private BlockTypeID(int blockId, byte dataId) {
+            this.blockId = blockId;
+            this.dataId = dataId;
+        }
+
+        int getBlockId() {
+            return blockId;
+        }
+
+        byte getDataId() {
+            return dataId;
+        }
+    }
+}

SpigotCore_8/src/de/steamwar/sql/Schematic_8.java

@@ -17,7 +17,6 @@ import com.sk89q.worldedit.regions.CuboidRegion;
 import com.sk89q.worldedit.session.ClipboardHolder;
 import com.sk89q.worldedit.world.registry.WorldData;
 import org.bukkit.Bukkit;
-import org.bukkit.Material;
 import org.bukkit.entity.Player;
 
 import javax.annotation.Nullable;
@@ -71,6 +70,7 @@ class Schematic_8 {
     }
 
     public static class SpongeSchematicReader implements ClipboardReader {
+
         private final NBTInputStream inputStream;
         private int schematicVersion = -1;
 
@@ -105,6 +105,8 @@ class Schematic_8 {
 
         @SuppressWarnings("deprecation")
         private BlockArrayClipboard readSchematic(CompoundTag schematicTag) throws IOException {
+            final Map<String, IDConverter.BlockTypeID> ids = IDConverter.getMap();
+
             Map<String, Tag> schematic = schematicTag.getValue();
             int width = (requireTag(schematic, "Width", ShortTag.class)).getValue();
             int height = (requireTag(schematic, "Height", ShortTag.class)).getValue();
@@ -152,14 +154,16 @@ class Schematic_8 {
                 String palettePart = (String)iterator.next();
                 id = requireTag(paletteObject, palettePart, IntTag.class).getValue();
 
-                String matName = palettePart.split(":")[1].split("\\[")[0];
+                IDConverter.BlockTypeID blockID = ids.get(palettePart);
-                Material material = Material.getMaterial(matName);
+                if(blockID == null){
-                if(material == null){
+                    blockID = ids.get(palettePart.split("\\[")[0]);
-                    state = new BaseBlock(0); //AIR
-                    continue;
                 }
 
-                state = new BaseBlock(material.getId());
+                if(blockID == null){
+                    state = new BaseBlock(0); //AIR
+                }else{
+                    state = new BaseBlock(blockID.getBlockId(), blockID.getDataId());
+                }
             }
 
             byte[] blocks = requireTag(schematic, "BlockData", ByteArrayTag.class).getValue();