src/de/steamwar/sql/Event.java

@@ -32,6 +32,10 @@ import java.util.List;
 @AllArgsConstructor
 public class Event {
 
+    static {
+        SchematicType.Normal.name(); // Ensure SchematicType is loaded.
+    }
+
     private static final Table<Event> table = new Table<>(Event.class);
 
     private static final SelectStatement<Event> byCurrent = new SelectStatement<>(table, "SELECT * FROM Event WHERE Start < now() AND End > now()");

src/de/steamwar/sql/NodeDownload.java

@@ -26,7 +26,7 @@ import lombok.AllArgsConstructor;
 
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
-import java.security.Timestamp;
+import java.sql.Timestamp;
 import java.time.Instant;
 
 @AllArgsConstructor

src/de/steamwar/sql/SchematicNode.java

@@ -20,9 +20,7 @@
 package de.steamwar.sql;
 
 import de.steamwar.sql.internal.*;
-import lombok.AccessLevel;
 import lombok.Getter;
-import lombok.Setter;
 
 import java.sql.Timestamp;
 import java.time.Instant;
@@ -32,6 +30,7 @@ import java.util.function.Predicate;
 public class SchematicNode {
 
     static {
+        SchematicType.Normal.name(); // Ensure SchematicType is loaded.
         new SqlTypeMapper<>(SchematicNode.class, null, (rs, identifier) -> { throw new SecurityException("SchematicNode cannot be used as type (recursive select)"); }, (st, index, value) -> st.setInt(index, value.nodeId));
     }
 

src/de/steamwar/sql/internal/SqlTypeMapper.java

@@ -32,7 +32,12 @@ public final class SqlTypeMapper<T> {
     private static final Map<Class<?>, SqlTypeMapper<?>> mappers = new IdentityHashMap<>();
 
     public static <T> SqlTypeMapper<T> getMapper(Class<?> clazz) {
-        return (SqlTypeMapper<T>) mappers.get(clazz);
+        SqlTypeMapper<T> result = (SqlTypeMapper<T>) mappers.get(clazz);
+
+        if(result == null)
+            throw new SecurityException("Unregistered mapper requested: " + clazz.getName());
+
+        return result;
     }
 
     public static <T extends Enum<T>> void ordinalEnumMapper(Class<T> type) {