Refactor parameter setting

.gitignore

@@ -4,3 +4,4 @@
 /.classpath
 /bin/
 /.settings/org.eclipse.buildship.core.prefs
+/.idea/

src/main/java/org/itsallcode/jdbc/Context.java

@@ -8,16 +8,6 @@ public final class Context {
     private Context() {
     }
 
-    /**
-     * Get the configured {@link ParameterMapper}.
-     * 
-     * @return parameter mapper
-     */
-    @SuppressWarnings("java:S2325") // Not-static by intention
-    public ParameterMapper getParameterMapper() {
-        return ParameterMapper.create();
-    }
-
     /**
      * Create a new builder for {@link Context} objects.
      * 

src/main/java/org/itsallcode/jdbc/SimpleConnection.java

@@ -11,6 +11,7 @@
 import org.itsallcode.jdbc.resultset.*;
 import org.itsallcode.jdbc.resultset.generic.Row;
 import org.itsallcode.jdbc.statement.ConvertingPreparedStatement;
+import org.itsallcode.jdbc.statement.ParamSetterProvider;
 
 /**
  * A simplified version of a JDBC {@link Connection}. Create new connections
@@ -22,11 +23,13 @@ public class SimpleConnection implements AutoCloseable {
     private final Connection connection;
     private final Context context;
     private final DbDialect dialect;
+    private final ParamSetterProvider paramSetterProvider;
 
     SimpleConnection(final Connection connection, final Context context, final DbDialect dialect) {
         this.connection = Objects.requireNonNull(connection, "connection");
         this.context = Objects.requireNonNull(context, "context");
         this.dialect = Objects.requireNonNull(dialect, "dialect");
+        this.paramSetterProvider = new ParamSetterProvider(dialect);
     }
 
     /**
@@ -102,7 +105,7 @@ SimplePreparedStatement prepareStatement(final String sql) {
     }
 
     private PreparedStatement wrap(final PreparedStatement preparedStatement) {
-        return new ConvertingPreparedStatement(preparedStatement, context.getParameterMapper());
+        return new ConvertingPreparedStatement(preparedStatement, paramSetterProvider);
     }
 
     /**

src/main/java/org/itsallcode/jdbc/dialect/ColumnValueSetter.java

@@ -0,0 +1,9 @@
+package org.itsallcode.jdbc.dialect;
+
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+
+public interface ColumnValueSetter<T> {
+
+    void setObject(PreparedStatement stmt, int parameterIndex, T object) throws SQLException;
+}

src/main/java/org/itsallcode/jdbc/dialect/DbDialect.java

@@ -22,4 +22,6 @@ public interface DbDialect {
      * @return extractor
      */
     ColumnValueExtractor createExtractor(final ColumnMetaData column);
+
+    <T> ColumnValueSetter<T> createSetter(Class<T> type);
 }

src/main/java/org/itsallcode/jdbc/dialect/ExasolDialect.java

@@ -1,11 +1,16 @@
 package org.itsallcode.jdbc.dialect;
 
+import java.time.*;
+import java.time.format.DateTimeFormatter;
+
 import org.itsallcode.jdbc.resultset.generic.ColumnMetaData;
 
 /**
  * Dialect for the Exasol database.
  */
 public class ExasolDialect extends AbstractDbDialect {
+    private static final DateTimeFormatter DATE_TIME_FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");
+    private static final ZoneId UTC_ZONE = ZoneId.of("UTC");
 
     /**
      * Create a new instance.
@@ -24,4 +29,19 @@ public ColumnValueExtractor createExtractor(final ColumnMetaData column) {
         default -> Extractors.generic();
         };
     }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public <T> ColumnValueSetter<T> createSetter(final Class<T> type) {
+        if (type == LocalDate.class) {
+            return (ColumnValueSetter<T>) Setters.localDateToString();
+        }
+        if (type == Instant.class) {
+            return (ColumnValueSetter<T>) Setters.instantToString(DATE_TIME_FORMATTER, UTC_ZONE);
+        }
+        if (type == LocalDateTime.class) {
+            return (ColumnValueSetter<T>) Setters.localDateTimeToString(DATE_TIME_FORMATTER);
+        }
+        return Setters.generic();
+    }
 }

src/main/java/org/itsallcode/jdbc/dialect/Extractors.java

@@ -6,26 +6,22 @@
 
 final class Extractors {
 
+    @SuppressWarnings("java:S2143") // Need to use calendar api
+    private final static Calendar UTC_CALENDAR = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
+
     private Extractors() {
     }
 
     static ColumnValueExtractor timestampToUTCInstant() {
-        final Calendar utcCalendar = createUtcCalendar();
-        return nonNull((resultSet, columnIndex) -> resultSet.getTimestamp(columnIndex, utcCalendar).toInstant());
+        return nonNull((resultSet, columnIndex) -> resultSet.getTimestamp(columnIndex, UTC_CALENDAR).toInstant());
     }
 
     public static ColumnValueExtractor timestampToInstant() {
         return nonNull((resultSet, columnIndex) -> resultSet.getTimestamp(columnIndex).toInstant());
     }
 
     static ColumnValueExtractor dateToLocalDate() {
-        final Calendar utcCalendar = createUtcCalendar();
-        return nonNull((resultSet, columnIndex) -> resultSet.getDate(columnIndex, utcCalendar).toLocalDate());
-    }
-
-    @SuppressWarnings("java:S2143") // Need to use calendar api
-    private static Calendar createUtcCalendar() {
-        return Calendar.getInstance(TimeZone.getTimeZone("UTC"));
+        return nonNull((resultSet, columnIndex) -> resultSet.getDate(columnIndex, UTC_CALENDAR).toLocalDate());
     }
 
     private static ColumnValueExtractor nonNull(final ColumnValueExtractor extractor) {

src/main/java/org/itsallcode/jdbc/dialect/H2Dialect.java

@@ -29,4 +29,9 @@ public ColumnValueExtractor createExtractor(final ColumnMetaData column) {
         default -> Extractors.generic();
         };
     }
+
+    @Override
+    public <T> ColumnValueSetter<T> createSetter(final Class<T> type) {
+        return Setters.generic();
+    }
 }

src/main/java/org/itsallcode/jdbc/dialect/Setters.java

@@ -0,0 +1,30 @@
+package org.itsallcode.jdbc.dialect;
+
+import java.sql.PreparedStatement;
+import java.time.*;
+import java.time.format.DateTimeFormatter;
+
+public final class Setters {
+    private Setters() {
+    }
+
+    public static <T> ColumnValueSetter<T> generic() {
+        return PreparedStatement::setObject;
+    }
+
+    static ColumnValueSetter<LocalDate> localDateToString() {
+        return (final PreparedStatement stmt, final int parameterIndex, final LocalDate date) -> stmt
+                .setString(parameterIndex, date.toString());
+    }
+
+    public static ColumnValueSetter<Instant> instantToString(final DateTimeFormatter dateTimeFormatter,
+            final ZoneId timeZone) {
+        return (final PreparedStatement stmt, final int parameterIndex, final Instant instant) -> stmt
+                .setString(parameterIndex, dateTimeFormatter.format(LocalDateTime.ofInstant(instant, timeZone)));
+    }
+
+    public static ColumnValueSetter<LocalDateTime> localDateTimeToString(final DateTimeFormatter dateTimeFormatter) {
+        return (final PreparedStatement stmt, final int parameterIndex, final LocalDateTime localDateTime) -> stmt
+                .setString(parameterIndex, dateTimeFormatter.format(localDateTime));
+    }
+}

src/main/java/org/itsallcode/jdbc/statement/ConvertingPreparedStatement.java

@@ -3,33 +3,31 @@
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
 
-import org.itsallcode.jdbc.ParameterMapper;
 
 /**
  * A {@link PreparedStatement} that delegates all methods and converts parameter
  * value of {@link #convert(Object)} using a {@link ParameterMapper}.
  */
 public class ConvertingPreparedStatement extends DelegatingPreparedStatement {
-
-    private final ParameterMapper parameterMapper;
+    private final PreparedStatement originalDelegate;
+    private final ParamSetterProvider paramSetterProvider;
 
     /**
      * Create a new instance.
      * 
-     * @param delegate        delegate
-     * @param parameterMapper parameter mapper
+     * @param delegate            delegate
+     * @param paramSetterProvider parameter setter provider
      */
-    public ConvertingPreparedStatement(final PreparedStatement delegate, final ParameterMapper parameterMapper) {
+    public ConvertingPreparedStatement(final PreparedStatement delegate,
+            final ParamSetterProvider paramSetterProvider) {
         super(delegate);
-        this.parameterMapper = parameterMapper;
+        this.originalDelegate = delegate;
+        this.paramSetterProvider = paramSetterProvider;
     }
 
     @Override
     public void setObject(final int parameterIndex, final Object x) throws SQLException {
-        super.setObject(parameterIndex, convert(x));
-    }
-
-    private Object convert(final Object object) {
-        return parameterMapper.map(object);
+        paramSetterProvider.findSetter(x)
+                .setObject(originalDelegate, parameterIndex, x);
     }
 }

src/main/java/org/itsallcode/jdbc/statement/ParamSetterProvider.java

@@ -0,0 +1,25 @@
+package org.itsallcode.jdbc.statement;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.itsallcode.jdbc.dialect.*;
+
+public class ParamSetterProvider {
+    private static final ColumnValueSetter<Object> GENERIC_SETTER = Setters.generic();
+    private final DbDialect dialect;
+    private final Map<Class<?>, ColumnValueSetter<Object>> setters = new HashMap<>();
+
+    public ParamSetterProvider(final DbDialect dialect) {
+        this.dialect = dialect;
+    }
+
+    @SuppressWarnings("unchecked")
+    ColumnValueSetter<Object> findSetter(final Object object) {
+        if (object == null) {
+            return GENERIC_SETTER;
+        }
+        return setters.computeIfAbsent(object.getClass(),
+                type -> (ColumnValueSetter<Object>) dialect.createSetter(type));
+    }
+}

src/test/java/org/itsallcode/jdbc/H2TypeTest.java

@@ -79,10 +79,8 @@ void preparedStatementSetParameter(final TypeTest test) {
         try (final SimpleConnection connection = H2TestFixture.createMemConnection();
                 final SimpleResultSet<Object> result = connection
                         .query("select ?",
-                                preparedStatement -> preparedStatement.setObject(1,
-                                        value),
-                                (resultSet, rowNum) -> resultSet
-                                        .getObject(1, value.getClass()))) {
+                                stmt -> stmt.setObject(1, value),
+                                (rs, rowNum) -> rs.getObject(1, value.getClass()))) {
             assertThat(result.toList()).containsExactly(value);
         }
     }