SQL serialization bug fixes for null and complex value types

ojcms-beans/src/main/java/de/adito/ojcms/beans/literals/fields/serialization/IAutoSerializableField.java

@@ -21,4 +21,10 @@ default VALUE fromPersistent(VALUE pSerialValue)
   {
     return pSerialValue;
   }
+
+  @Override
+  default Class<VALUE> getSerialValueType()
+  {
+    return getDataType();
+  }
 }

ojcms-beans/src/main/java/de/adito/ojcms/beans/literals/fields/serialization/ISerializableField.java

@@ -27,4 +27,9 @@ public interface ISerializableField<VALUE, SERIAL extends Serializable> extends
    * @return the original field value
    */
   VALUE fromPersistent(SERIAL pSerialValue);
+
+  /**
+   * The serial value's type.
+   */
+  Class<SERIAL> getSerialValueType();
 }

ojcms-beans/src/main/java/de/adito/ojcms/beans/literals/fields/serialization/ISerializableFieldJson.java

@@ -21,4 +21,10 @@ default VALUE fromPersistent(String pSerialString)
   {
     return new Gson().fromJson(pSerialString, getDataType());
   }
+
+  @Override
+  default Class<String> getSerialValueType()
+  {
+    return String.class;
+  }
 }

ojcms-beans/src/main/java/de/adito/ojcms/beans/literals/fields/types/DateField.java

@@ -48,6 +48,12 @@ public Long toPersistent(Instant pValue)
     return pValue.toEpochMilli();
   }
 
+  @Override
+  public Class<Long> getSerialValueType()
+  {
+    return Long.class;
+  }
+
   @Override
   public Instant fromPersistent(Long pSerialValue)
   {

ojcms-beans/src/main/java/de/adito/ojcms/beans/literals/fields/types/EnumField.java

@@ -49,6 +49,12 @@ public ENUM fromPersistent(String pSerialString)
     }
   }
 
+  @Override
+  public Class<String> getSerialValueType()
+  {
+    return String.class;
+  }
+
   @Override
   public ENUM copyValue(ENUM pEnum, ECopyMode pMode, CustomFieldCopy<?>... pCustomFieldCopies)
   {

ojcms-sqlbuilder/src/main/java/de/adito/ojcms/sqlbuilder/executors/StatementExecutor.java

@@ -7,6 +7,7 @@
 import java.sql.*;
 import java.util.List;
 import java.util.function.Supplier;
+import java.util.logging.Logger;
 
 /**
  * Implementation of a statement executor based on a function that will be provided with a {@link PreparedStatement}.
@@ -17,6 +18,8 @@
  */
 class StatementExecutor<RESULT> implements IStatementExecutor<RESULT>
 {
+  private static final Logger LOGGER = Logger.getLogger(StatementExecutor.class.getName());
+
   private final Supplier<Connection> connectionSupplier;
   private final ThrowingFunction<PreparedStatement, RESULT, SQLException> executor;
   private Connection connection;
@@ -47,7 +50,9 @@ public RESULT executeStatement(String pSQLStatement, List<ISerialValue> pArgs)
       for (ISerialValue arg : pArgs)
         arg.applyToStatement(statement, argIndex++);
 
-      return executor.apply(statement);
+      final RESULT result = executor.apply(statement);
+      LOGGER.info("SQL executed: " + pSQLStatement);
+      return result;
     }
     catch (SQLException pE)
     {

ojcms-sqlbuilder/src/main/java/de/adito/ojcms/sqlbuilder/result/ResultRow.java

@@ -99,7 +99,8 @@ public <KEY, COLUMN extends IColumnIdentification<?>> Map<KEY, Object> toMap(COL
   {
     //noinspection unchecked
     return Stream.of(pColumnsToInclude)
-        .collect(Collectors.toMap(pColumnMapper, pColumn -> get((IColumnIdentification) pColumn)));
+        //Allow null values
+        .collect(HashMap::new, (pMap, pColumn) -> pMap.put(pColumnMapper.apply(pColumn), get((IColumnIdentification) pColumn)), HashMap::putAll);
   }
 
   /**

ojcms-sqlbuilder/src/main/java/de/adito/ojcms/sqlbuilder/serialization/DefaultValueSerializer.java

@@ -21,6 +21,7 @@
 public class DefaultValueSerializer implements IValueSerializer
 {
   private static final Map<Class, _SupportedSerialization<?, ?>> SUPPORTED_SERIALIZATIONS = new HashMap<>();
+  protected static final ISerialValue NULL_SERIAL_VALUE = new _NullSerialValue();
 
   /*
    * Adds all supported data types.
@@ -58,8 +59,7 @@ public <VALUE> ISerialValue toSerial(IColumnValueTuple<VALUE> pColumnValueTuple)
   @Nullable
   public <VALUE> VALUE fromSerial(IColumnIdentification<VALUE> pColumn, ResultSet pResultSet, int pIndex)
   {
-    final _SupportedSerialization<VALUE, ?> serialization = _getSerializationForType(pColumn.getDataType());
-    return serialization.retrieveConvertedResult(pResultSet, pIndex);
+    return retrieveSerialValue(pColumn.getDataType(), pResultSet, pIndex);
   }
 
   /**
@@ -73,7 +73,7 @@ public <VALUE> VALUE fromSerial(IColumnIdentification<VALUE> pColumn, ResultSet
   protected <VALUE, SERIAL extends Serializable> ISerialValue createSerialValue(Class<VALUE> pDataType, VALUE pDataValue)
   {
     if (pDataValue == null)
-      return null;
+      return NULL_SERIAL_VALUE;
 
     final _SupportedSerialization<VALUE, SERIAL> serialization = _getSerializationForType(pDataType);
 
@@ -96,6 +96,21 @@ public void applyToStatement(PreparedStatement pStatement, int pIndex)
     };
   }
 
+  /**
+   * Retrieves a value from a {@link ResultSet} and converts it back to its original data value.
+   *
+   * @param pValueType the value type to retrieve
+   * @param pResultSet the SQL result set to retrieve the value from
+   * @param pIndex     the index to retrieve the result from
+   * @return the original data value
+   */
+  @Nullable
+  protected <VALUE> VALUE retrieveSerialValue(Class<VALUE> pValueType, ResultSet pResultSet, int pIndex)
+  {
+    final _SupportedSerialization<VALUE, ?> serialization = _getSerializationForType(pValueType);
+    return serialization.retrieveConvertedResult(pResultSet, pIndex);
+  }
+
   /**
    * Resolves a {@link _SupportedSerialization} for a specific data type.
    * Throws a {@link OJDatabaseException} if the data type is not supported.
@@ -237,4 +252,23 @@ private interface _ResultRetriever<SERIAL>
      */
     SERIAL retrieveResult(ResultSet pResultSet, int pIndex) throws SQLException;
   }
+
+  /**
+   * Null serial value.
+   */
+  private static class _NullSerialValue implements ISerialValue
+  {
+    @Override
+    public void applyToStatement(PreparedStatement pStatement, int pIndex)
+    {
+      try
+      {
+        pStatement.setObject(pIndex, null);
+      }
+      catch (SQLException pE)
+      {
+        throw new OJDatabaseException("Unable to apply parameter to statement!", pE);
+      }
+    }
+  }
 }

ojcms-sqldatasource/src/main/java/de/adito/ojcms/sql/datasource/util/BeanSQLSerializer.java

@@ -50,7 +50,7 @@ private <VALUE, SERIAL extends Serializable> ISerialValue _toSerialValue(FieldVa
     final VALUE value = pTuple.getValue();
 
     if (value == null)
-      return null;
+      return NULL_SERIAL_VALUE;
 
     if (!(field instanceof ISerializableField))
       throw new BeanSerializationException(_notSerializableMessage(field, true));
@@ -70,19 +70,21 @@ private <VALUE, SERIAL extends Serializable> ISerialValue _toSerialValue(FieldVa
    * @param <VALUE>    the data type of the bean field
    * @return the converted data value
    */
-  @SuppressWarnings("unchecked")
   private <VALUE, SERIAL extends Serializable> VALUE _fromPersistent(IColumnIdentification<?> pColumn, ResultSet pResultSet, int pIndex)
   {
-    final SERIAL serialValue = (SERIAL) super.fromSerial(pColumn, pResultSet, pIndex);
-
-    if (!(pColumn instanceof IBeanFieldTupleBased))
-      return (VALUE) serialValue;
+    if (!(pColumn instanceof IBeanFieldBased))
+      //noinspection unchecked
+      return (VALUE) super.fromSerial(pColumn, pResultSet, pIndex);
 
-    final IField<VALUE> field = ((IBeanFieldTupleBased<VALUE>) pColumn).getFieldValueTuple().getField();
+    //noinspection unchecked
+    final IField<VALUE> field = ((IBeanFieldBased<VALUE>) pColumn).getBeanField();
     if (!(field instanceof ISerializableField))
       throw new BeanSerializationException(_notSerializableMessage(field, false));
 
-    return ((ISerializableField<VALUE, SERIAL>) field).fromPersistent(serialValue);
+    final ISerializableField<VALUE, SERIAL> serializableField = (ISerializableField<VALUE, SERIAL>) field;
+    final SERIAL serialValue = retrieveSerialValue(serializableField.getSerialValueType(), pResultSet, pIndex);
+
+    return serializableField.fromPersistent(serialValue);
   }
 
   /**