[core] Harden catalog table type dispatch and external path parsing

paimon-core/src/main/java/org/apache/paimon/catalog/AbstractCatalog.java

@@ -415,6 +415,8 @@ private List<Path> getSchemaExternalPaths(List<TableSchema> schemas) {
                         })
                 .filter(Objects::nonNull)
                 .flatMap(externalPath -> Arrays.stream(externalPath.split(",")))
+                .map(String::trim)
+                .filter(path -> !path.isEmpty())
                 .map(Path::new)
                 .distinct()
                 .collect(Collectors.toList());
@@ -445,7 +447,8 @@ public void createTable(Identifier identifier, Schema schema, boolean ignoreIfEx
         copyTableDefaultOptions(schema.options());
         validateCreateTable(schema, false);
 
-        switch (Options.fromMap(schema.options()).get(TYPE)) {
+        TableType type = Options.fromMap(schema.options()).get(TYPE);
+        switch (type) {
             case TABLE:
             case MATERIALIZED_TABLE:
                 createTableImpl(identifier, schema);
@@ -456,6 +459,11 @@ public void createTable(Identifier identifier, Schema schema, boolean ignoreIfEx
             case OBJECT_TABLE:
                 createObjectTable(identifier, schema);
                 break;
+            default:
+                // silently falling through would report a successful DDL without
+                // creating anything
+                throw new UnsupportedOperationException(
+                        "Create table with type '" + type + "' is not supported.");
         }
     }
 

paimon-core/src/main/java/org/apache/paimon/jdbc/JdbcCatalog.java

@@ -437,6 +437,11 @@ public void createTable(Identifier identifier, Schema schema, boolean ignoreIfEx
                             "Failed to create table " + identifier.getFullName(), e);
                 }
                 break;
+            default:
+                // silently falling through would report a successful DDL without
+                // creating anything
+                throw new UnsupportedOperationException(
+                        "Create table with type '" + tableType + "' is not supported.");
         }
     }
 

paimon-core/src/test/java/org/apache/paimon/catalog/FileSystemCatalogTest.java

@@ -69,6 +69,43 @@ public void testCreateTableCaseSensitive() throws Exception {
         catalog.createTable(identifier, schema, false);
     }
 
+    @Test
+    public void testCreateTableWithUnsupportedTypeFailsLoudly() throws Exception {
+        catalog.createDatabase("test_db", false);
+        Identifier identifier = Identifier.create("test_db", "iceberg_t");
+        Schema schema =
+                Schema.newBuilder()
+                        .column("k", DataTypes.INT())
+                        .option("type", "iceberg-table")
+                        .build();
+
+        // falling through the switch silently would report a successful DDL without
+        // creating anything
+        assertThatThrownBy(() -> catalog.createTable(identifier, schema, false))
+                .isInstanceOf(UnsupportedOperationException.class)
+                .hasMessageContaining("iceberg-table");
+        assertThat(catalog.listTables("test_db")).doesNotContain(identifier.getObjectName());
+    }
+
+    @Test
+    public void testDropTableToleratesBlankExternalPaths() throws Exception {
+        catalog.createDatabase("test_db", false);
+        Identifier identifier = Identifier.create("test_db", "external_paths_t");
+        Path external = new Path(new Path(warehouse), "test_db/external_dir");
+        fileIO.mkdirs(external);
+        Schema schema =
+                Schema.newBuilder()
+                        .column("k", DataTypes.INT())
+                        .option("data-file.external-paths", " , " + external + " ,")
+                        .build();
+        catalog.createTable(identifier, schema, false);
+
+        // the drop must not crash on the blank segments the create-time validation
+        // tolerates
+        catalog.dropTable(identifier, false);
+        assertThat(catalog.listTables("test_db")).doesNotContain(identifier.getObjectName());
+    }
+
     @Test
     public void testValidateFormatTableDefaultOptions() throws Exception {
         String database = "format_table_default_validation_db";