Refactoring usage of parameter value converter

Author: jeffgbutler

src/main/java/org/mybatis/dynamic/sql/BindableColumn.java

@@ -26,9 +26,7 @@
  * 
  * @author Jeff Butler
  *
- * @param <T> - even though the type is not directly used in this class,
- *     it is used by the compiler to match columns with conditions so it should
- *     not be removed.
+ * @param <T> - the Java type that corresponds to this column
 */
 public interface BindableColumn<T> extends BasicColumn {
 
@@ -49,4 +47,8 @@ default Optional<String> typeHandler() {
     default Optional<RenderingStrategy> renderingStrategy() {
         return Optional.empty();
     }
+
+    default Optional<ParameterTypeConverter<T>> parameterTypeConverter() {
+        return Optional.empty();
+    }
 }

src/main/java/org/mybatis/dynamic/sql/ParameterTypeConverter.java

@@ -21,7 +21,10 @@
  * to somewhat mimic the function of a MyBatis type handler for runtimes such as Spring that don't have
  * a corresponding concept.
  *
- * <p>A parameter type converter is associated with a SqlColumn
+ * <p>A parameter type converter is associated with a SqlColumn.
+ * 
+ * <p>A parameter type converter is compatible with Spring's general Converter interface so existing converters can be reused
+ * here if they are marked with this additional interface.
  *
  * <p>The converter is only used for parameters - it is not used for result set processing. The converter will be
  * called in the following circumstances:
@@ -31,7 +34,7 @@
  *     <li>Parameters in an update statement</li>
  *     <li>Parameters in a where clause in any statement</li>
  * </ul>
- *
+ * 
  * @param <S> Source Type
  *
  * @see SqlColumn

src/main/java/org/mybatis/dynamic/sql/SqlColumn.java

@@ -41,7 +41,7 @@ private SqlColumn(Builder builder) {
     }
 
     @SuppressWarnings("unchecked")
-    protected <S> SqlColumn(SqlColumn<S> sqlColumn) {
+    protected SqlColumn(SqlColumn<?> sqlColumn) {
         name = sqlColumn.name;
         table = sqlColumn.table;
         jdbcType = sqlColumn.jdbcType;
@@ -75,6 +75,7 @@ public Optional<String> typeHandler() {
         return Optional.ofNullable(typeHandler);
     }
 
+    @Override
     public Optional<ParameterTypeConverter<T>> parameterTypeConverter() {
         return Optional.ofNullable(parameterTypeConverter);
     }

src/main/java/org/mybatis/dynamic/sql/insert/InsertDSL.java

@@ -80,7 +80,7 @@ public InsertDSL<T> toProperty(String property) {
             return InsertDSL.this;
         }
 
-        public InsertDSL<T> toPropertyWhenPresent(String property, Supplier<F> valueSupplier) {
+        public InsertDSL<T> toPropertyWhenPresent(String property, Supplier<Object> valueSupplier) {
             columnMappings.add(PropertyWhenPresentMapping.of(column, property, valueSupplier));
             return InsertDSL.this;
         }

src/main/java/org/mybatis/dynamic/sql/insert/render/GeneralInsertValuePhraseVisitor.java

@@ -19,7 +19,6 @@
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Function;
 
-import org.mybatis.dynamic.sql.ParameterTypeConverter;
 import org.mybatis.dynamic.sql.SqlColumn;
 import org.mybatis.dynamic.sql.render.RenderingStrategy;
 import org.mybatis.dynamic.sql.util.AbstractColumnMapping;
@@ -70,14 +69,10 @@ public <T> Optional<FieldAndValueAndParameters> visit(ValueWhenPresentMapping<T>
         return mapping.value().flatMap(v -> buildValueFragment(mapping, v));
     }
 
-    private <T> Optional<FieldAndValueAndParameters> buildValueFragment(AbstractColumnMapping<T> mapping, T value) {
-        Optional<ParameterTypeConverter<T>> typeConverter = mapping.parameterTypeConverter();
-        
-        return buildFragment(mapping, typeConverter.map(tc -> tc.convert(value))
-                .orElse(value));
-        
+    private <T> Optional<FieldAndValueAndParameters> buildValueFragment(AbstractColumnMapping<T> mapping, Object value) {
+        return buildFragment(mapping, value);
     }
-
+    
     private <T> Optional<FieldAndValueAndParameters> buildFragment(AbstractColumnMapping<T> mapping, Object value) {
         String mapKey = RenderingStrategy.formatParameterMapKey(sequence);
 

src/main/java/org/mybatis/dynamic/sql/update/render/SetPhraseVisitor.java

@@ -108,7 +108,7 @@ public <T> Optional<FragmentAndParameters> visit(ColumnToColumnMapping<T> mappin
                 .buildOptional();
     }
 
-    private <T> Optional<FragmentAndParameters> buildFragment(AbstractColumnMapping<T> mapping, T value) {
+    private <T> Optional<FragmentAndParameters> buildFragment(AbstractColumnMapping<T> mapping, Object value) {
         String mapKey = RenderingStrategy.formatParameterMapKey(sequence);
 
         String jdbcPlaceholder = mapping.mapColumn(toJdbcPlaceholder(mapKey));

src/main/java/org/mybatis/dynamic/sql/util/AbstractColumnMapping.java

@@ -16,10 +16,8 @@
 package org.mybatis.dynamic.sql.util;
 
 import java.util.Objects;
-import java.util.Optional;
 import java.util.function.Function;
 
-import org.mybatis.dynamic.sql.ParameterTypeConverter;
 import org.mybatis.dynamic.sql.SqlColumn;
 
 public abstract class AbstractColumnMapping<T> {
@@ -33,9 +31,5 @@ public <R> R mapColumn(Function<SqlColumn<?>, R> mapper) {
         return mapper.apply(column);
     }
 
-    public Optional<ParameterTypeConverter<T>> parameterTypeConverter() {
-        return column.parameterTypeConverter();
-    }
-    
     public abstract <R> R accept(ColumnMappingVisitor<R> visitor);
 }

src/main/java/org/mybatis/dynamic/sql/util/PropertyWhenPresentMapping.java

@@ -21,9 +21,13 @@
 import org.mybatis.dynamic.sql.SqlColumn;
 
 public class PropertyWhenPresentMapping<T> extends PropertyMapping<T> {
-    private Supplier<?> valueSupplier;
+    /**
+     * The Supplier is of type Object because we need to allow for data type changes
+     * for Spring where there are no type handlers.
+     */
+    private Supplier<Object> valueSupplier;
 
-    private PropertyWhenPresentMapping(SqlColumn<T> column, String property, Supplier<T> valueSupplier) {
+    private PropertyWhenPresentMapping(SqlColumn<T> column, String property, Supplier<Object> valueSupplier) {
         super(column, property);
         this.valueSupplier = Objects.requireNonNull(valueSupplier);
     }
@@ -38,7 +42,7 @@ public <R> R accept(ColumnMappingVisitor<R> visitor) {
     }
 
     public static <T> PropertyWhenPresentMapping<T> of(SqlColumn<T> column, String property,
-            Supplier<T> valueSupplier) {
+            Supplier<Object> valueSupplier) {
         return new PropertyWhenPresentMapping<>(column, property, valueSupplier);
     }
 }

src/main/java/org/mybatis/dynamic/sql/util/ValueMapping.java

@@ -29,8 +29,9 @@ private ValueMapping(SqlColumn<T> column, Supplier<T> valueSupplier) {
         this.valueSupplier = Objects.requireNonNull(valueSupplier);
     }
 
-    public T value() {
-        return valueSupplier.get();
+    public Object value() {
+        return column.parameterTypeConverter().map(tc -> tc.convert(valueSupplier.get()))
+                .orElseGet(valueSupplier);
     }
 
     @Override

src/main/java/org/mybatis/dynamic/sql/util/ValueWhenPresentMapping.java

@@ -30,8 +30,12 @@ private ValueWhenPresentMapping(SqlColumn<T> column, Supplier<T> valueSupplier)
         this.valueSupplier = Objects.requireNonNull(valueSupplier);
     }
 
-    public Optional<T> value() {
-        return Optional.ofNullable(valueSupplier.get());
+    public Optional<Object> value() {
+        return Optional.ofNullable(valueSupplier.get()).map(this::convert);
+    }
+    
+    private Object convert(T value) {
+        return column.parameterTypeConverter().map(tc -> tc.convert(value)).orElse(value);
     }
 
     @Override