fixed review findings incl. implementation for issue #138

doc/changes/changes_10.3.0.md

@@ -4,15 +4,14 @@ Code name: Escape Wildcards
 
 ## Summary
 
-This release fixes lookup for tables with wildcards underscore `_` and percent `%`.
+This release fixes ambiguous results by escaping SQL wildcards such as underscore `_` and percent `%` in names of catalogs, schemas, and tables when retrieving column metadata from JDBC driver.
 
-Even when putting double quotes around the table name older releases of VSCJDBC passed the name to the JDBC driver and the JDBC driver returned the metadata for all matching tables expanding potential wildcards.
-
-The current release fixes this by escaping the wildcards before passing the table name to the JDBC driver.
+The release also adds a constructor enabling derived SQL dialects to add additional validators for adapter properties, hence removing the need to override method `AbstractSqlDialect.validateProperties()`.
 
 ## Bugfixes
 
-* #136: Column lookup for tables is not escaping wildcards
+* #136: Fixed column lookup for tables is not escaping wildcards
+* #138: Enabled SQL dialects to add property validators
 
 ## Dependency Updates
 

src/main/java/com/exasol/adapter/dialects/AbstractSqlDialect.java

@@ -46,6 +46,22 @@ public abstract class AbstractSqlDialect implements SqlDialect {
      */
     protected AbstractSqlDialect(final ConnectionFactory connectionFactory, final AdapterProperties properties,
             final Set<String> dialectSpecificProperties) {
+        this(connectionFactory, properties, dialectSpecificProperties, List.of());
+    }
+
+    /**
+     * Create a new instance of an {@link AbstractSqlDialect}.
+     *
+     * @param connectionFactory                 factory for JDBC connection to remote data source
+     * @param properties                        user properties
+     * @param dialectSpecificProperties         a set of properties that dialect supports additionally to the common set
+     *                                          {@link com.exasol.adapter.dialects.AbstractSqlDialect#COMMON_SUPPORTED_PROPERTIES}
+     * @param dialectSpecificPropertyValidators a collection of property validators the dialect wants to apply
+     *                                          additionally to the common validators
+     */
+    protected AbstractSqlDialect(final ConnectionFactory connectionFactory, final AdapterProperties properties,
+            final Set<String> dialectSpecificProperties,
+            final Collection<PropertyValidator> dialectSpecificPropertyValidators) {
         this.connectionFactory = connectionFactory;
         this.properties = properties;
         this.supportedProperties = new SupportedPropertiesValidator() //
@@ -59,7 +75,8 @@ protected AbstractSqlDialect(final ConnectionFactory connectionFactory, final Ad
                 .add(PropertyValidator.forStructureElement(supportsJdbcSchemas(), "schemas", SCHEMA_NAME_PROPERTY))
                 .add(ExceptionHandlingProperty.validator()) //
                 .add(DataTypeDetection.getValidator()) //
-                .add(TableCountLimit.getValidator());
+                .add(TableCountLimit.getValidator()) //
+                .addAll(dialectSpecificPropertyValidators);
     }
 
     /**

src/main/java/com/exasol/adapter/jdbc/BaseColumnMetadataReader.java

@@ -83,11 +83,7 @@ public List<ColumnMetadata> mapColumns(final String tableName) {
      */
     protected List<ColumnMetadata> mapColumns(final String catalogName, final String schemaName,
             final String tableName) {
-        final String tableNameEscaped = Wildcards.escape(tableName);
-        final String catalogNameEscaped = catalogName == null ? null : Wildcards.escape(catalogName);
-        final String schemaNameEscaped = schemaName == null ? null : Wildcards.escape(schemaName);
-        try (final ResultSet remoteColumns = this.connection.getMetaData().getColumns(catalogNameEscaped,
-                schemaNameEscaped, tableNameEscaped, ANY_COLUMN)) {
+        try (final ResultSet remoteColumns = getColumnMetadata(catalogName, schemaName, tableName)) {
             return getColumnsFromResultSet(remoteColumns);
         } catch (final SQLException exception) {
             throw new RemoteMetadataReaderException(ExaError.messageBuilder("E-VSCJDBC-1").message(
@@ -96,6 +92,15 @@ protected List<ColumnMetadata> mapColumns(final String catalogName, final String
         }
     }
 
+    private ResultSet getColumnMetadata(final String catalogName, final String schemaName, final String tableName)
+            throws SQLException {
+        return this.connection.getMetaData().getColumns( //
+                catalogName == null ? null : Wildcards.escape(catalogName), //
+                schemaName == null ? null : Wildcards.escape(schemaName), //
+                Wildcards.escape(tableName), //
+                ANY_COLUMN);
+    }
+
     /**
      * Read the columns result set.
      *

src/main/java/com/exasol/adapter/properties/ValidatorChain.java

@@ -1,7 +1,6 @@
 package com.exasol.adapter.properties;
 
-import java.util.ArrayList;
-import java.util.List;
+import java.util.*;
 
 import com.exasol.adapter.AdapterProperties;
 
@@ -23,6 +22,17 @@ public ValidatorChain add(final PropertyValidator validator) {
         return this;
     }
 
+    /**
+     * Add a list of property validators to the validator chain.
+     *
+     * @param validators
+     * @return this for fluent programming
+     */
+    public ValidatorChain addAll(final Collection<PropertyValidator> validators) {
+        this.propertyValidators.addAll(validators);
+        return this;
+    }
+
     @Override
     public void validate(final AdapterProperties properties) throws PropertyValidationException {
         for (final PropertyValidator validator : this.propertyValidators) {

src/test/java/com/exasol/adapter/jdbc/WildcardsTest.java

@@ -14,6 +14,7 @@ class WildcardsTest {
             "a _ a, a \\_ a", //
             "a % a, a \\% a", //
             "a _ b _ c, a \\_ b \\_ c", //
+            "a_b%c, a\\_b\\%c", //
     })
     void test(final String input, final String expected) {
         assertThat(Wildcards.escape(input), equalTo(expected));