Create empty factory for error handling

Author: sualeh

schemacrawler-ai-mcpserver/src/main/java/schemacrawler/tools/ai/mcpserver/EmptyDatabaseConnectionSource.java

@@ -16,7 +16,7 @@
 import org.springframework.lang.NonNull;
 import schemacrawler.schema.Catalog;
 import schemacrawler.schemacrawler.exceptions.SchemaCrawlerException;
-import schemacrawler.tools.ai.mcpserver.utility.CatalogFactory;
+import schemacrawler.tools.ai.mcpserver.utility.EmptyFactory;
 import schemacrawler.tools.ai.tools.FunctionDefinitionRegistry;
 import us.fatehi.utility.datasource.DatabaseConnectionSource;
 import us.fatehi.utility.datasource.DatabaseConnectionSources;
@@ -48,7 +48,7 @@ public McpServerInitializer(
         throw e;
       }
       isInErrorState = true;
-      connectionSource = new EmptyDatabaseConnectionSource();
+      connectionSource = EmptyFactory.createEmptyDatabaseConnectionSource();
     }
     this.connectionSource = connectionSource;
     this.isInErrorState = isInErrorState;
@@ -70,7 +70,7 @@ public McpServerInitializer(final McpServerContext context) {
       if (mcpTransport != McpServerTransportType.stdio) {
         throw e;
       }
-      catalog = CatalogFactory.createEmptyCatalog(e);
+      catalog = EmptyFactory.createEmptyCatalog(e);
       isInErrorState = true;
     }
     this.catalog = catalog;
@@ -84,7 +84,7 @@ public McpServerInitializer(final McpServerContext context) {
       if (mcpTransport != McpServerTransportType.stdio) {
         throw e;
       }
-      connectionSource = new EmptyDatabaseConnectionSource();
+      connectionSource = EmptyFactory.createEmptyDatabaseConnectionSource();
     }
     this.connectionSource = connectionSource;
   }

schemacrawler-ai-mcpserver/src/main/java/schemacrawler/tools/ai/mcpserver/McpServerInitializer.java

@@ -10,9 +10,11 @@
 
 import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.Proxy;
+import java.sql.DriverManager;
 import schemacrawler.schema.Catalog;
+import us.fatehi.utility.datasource.DatabaseConnectionSource;
 
-public class CatalogFactory {
+public class EmptyFactory {
 
   public static Catalog createEmptyCatalog(final Exception e) {
     final String baseErrorMessage =
@@ -50,4 +52,28 @@ public static Catalog createEmptyCatalog(final Exception e) {
         Proxy.newProxyInstance(
             Catalog.class.getClassLoader(), new Class<?>[] {Catalog.class}, handler);
   }
+
+  public static DatabaseConnectionSource createEmptyDatabaseConnectionSource() {
+
+    final InvocationHandler handler =
+        (proxy, method, args) -> {
+          switch (method.getName()) {
+            case "get":
+              return DriverManager.getConnection("jdbc:hsqldb::memory:");
+            case "releaseConnection":
+              return true;
+            case "close":
+            case "setFirstConnectionInitializer":
+              return null; // No-op
+            default:
+              throw new UnsupportedOperationException("Method not supported: " + method.getName());
+          }
+        };
+
+    return (DatabaseConnectionSource)
+        Proxy.newProxyInstance(
+            DatabaseConnectionSource.class.getClassLoader(),
+            new Class<?>[] {DatabaseConnectionSource.class},
+            handler);
+  }
 }