/*
    * Copyright 2004-2023 the original author or authors.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *    https://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.ibatis.sqlmap.engine.mapping.result;
  
  import com.ibatis.common.beans.Probe;
  import com.ibatis.common.beans.ProbeFactory;
  import com.ibatis.common.jdbc.exception.NestedSQLException;
  import com.ibatis.sqlmap.client.SqlMapException;
  import com.ibatis.sqlmap.engine.exchange.DataExchange;
  import com.ibatis.sqlmap.engine.impl.SqlMapClientImpl;
  import com.ibatis.sqlmap.engine.impl.SqlMapExecutorDelegate;
  import com.ibatis.sqlmap.engine.mapping.result.loader.ResultLoader;
  import com.ibatis.sqlmap.engine.mapping.sql.Sql;
  import com.ibatis.sqlmap.engine.mapping.statement.MappedStatement;
  import com.ibatis.sqlmap.engine.scope.ErrorContext;
  import com.ibatis.sqlmap.engine.scope.StatementScope;
  import com.ibatis.sqlmap.engine.type.DomCollectionTypeMarker;
  import com.ibatis.sqlmap.engine.type.DomTypeMarker;
  import com.ibatis.sqlmap.engine.type.TypeHandler;
  import com.ibatis.sqlmap.engine.type.TypeHandlerFactory;
  
  import java.sql.ResultSet;
  import java.sql.SQLException;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  import java.util.StringTokenizer;
  
  import javax.xml.parsers.DocumentBuilderFactory;
  import javax.xml.parsers.ParserConfigurationException;
  
  import org.w3c.dom.Document;
  
  /**
   * Basic implementation of ResultMap interface.
   */
  public class ResultMap {
  
    /** The Constant PROBE. */
    private static final Probe PROBE = ProbeFactory.getProbe();
  
    /** The Constant KEY_SEPARATOR. */
    private static final String KEY_SEPARATOR = "\002";
  
    /** The id. */
    private String id;
  
    /** The result class. */
    private Class resultClass;
  
    /** The result mappings. */
    // DO NOT ACCESS EITHER OF THESE OUTSIDE OF THEIR BEAN GETTER/SETTER
    private ResultMapping[] resultMappings;
  
    /** The remappable result mappings. */
    private ThreadLocal remappableResultMappings = new ThreadLocal();
  
    /** The data exchange. */
    private DataExchange dataExchange;
  
    /** The nested result mappings. */
    private List nestedResultMappings;
  
    /** The discriminator. */
    private Discriminator discriminator;
  
    /** The group by props. */
    private Set groupByProps;
  
    /** The xml name. */
    private String xmlName;
  
    /** The resource. */
    private String resource;
  
    /** The delegate. */
    protected SqlMapExecutorDelegate delegate;
  
    /** The allow remapping. */
    protected boolean allowRemapping = false;
  
   /** The Constant NO_VALUE. */
   public static final Object NO_VALUE = new Object();
 
   /**
    * Constructor to pass a SqlMapExecutorDelegate in.
    *
    * @param delegate
    *          - the SqlMapExecutorDelegate
    */
   public ResultMap(SqlMapExecutorDelegate delegate) {
     this.delegate = delegate;
   }
 
   /**
    * Getter for the SqlMapExecutorDelegate.
    *
    * @return - the delegate
    */
   public SqlMapExecutorDelegate getDelegate() {
     return delegate;
   }
 
   /**
    * Gets the id.
    *
    * @return the id
    */
   public String getId() {
     return id;
   }
 
   /**
    * Setter for the ID.
    *
    * @param id
    *          - the new ID
    */
   public void setId(String id) {
     this.id = id;
   }
 
   /**
    * Gets the result class.
    *
    * @return the result class
    */
   public Class getResultClass() {
     return resultClass;
   }
 
   /**
    * Gets the unique key.
    *
    * @param keyPrefix
    *          the key prefix
    * @param values
    *          the values
    *
    * @return the unique key
    */
   public Object getUniqueKey(String keyPrefix, Object[] values) {
     if (groupByProps != null) {
       StringBuilder keyBuffer;
       if (keyPrefix != null)
         keyBuffer = new StringBuilder(keyPrefix);
       else
         keyBuffer = new StringBuilder();
       for (int i = 0; i < getResultMappings().length; i++) {
         String propertyName = getResultMappings()[i].getPropertyName();
         if (groupByProps.contains(propertyName)) {
           keyBuffer.append(values[i]);
           keyBuffer.append('-');
         }
       }
       if (keyBuffer.length() < 1) {
         return null;
       } else {
         // seperator value not likely to appear in a database
         keyBuffer.append(KEY_SEPARATOR);
         return keyBuffer.toString();
       }
     } else {
       return null;
     }
   }
 
   /**
    * Gets the unique key.
    *
    * @param values
    *          the values
    *
    * @return the unique key
    */
   public Object getUniqueKey(Object[] values) {
     return getUniqueKey(null, values);
   }
 
   /**
    * Setter for the result class (what the results will be mapped into).
    *
    * @param resultClass
    *          - the result class
    */
   public void setResultClass(Class resultClass) {
     this.resultClass = resultClass;
   }
 
   /**
    * Getter for the DataExchange object to be used.
    *
    * @return - the DataExchange object
    */
   public DataExchange getDataExchange() {
     return dataExchange;
   }
 
   /**
    * Setter for the DataExchange object to be used.
    *
    * @param dataExchange
    *          - the new DataExchange object
    */
   public void setDataExchange(DataExchange dataExchange) {
     this.dataExchange = dataExchange;
   }
 
   /**
    * Getter (used by DomDataExchange) for the xml name of the results.
    *
    * @return - the name
    */
   public String getXmlName() {
     return xmlName;
   }
 
   /**
    * Setter (used by the SqlMapBuilder) for the xml name of the results.
    *
    * @param xmlName
    *          - the name
    */
   public void setXmlName(String xmlName) {
     this.xmlName = xmlName;
   }
 
   /**
    * Getter for the resource (used to report errors).
    *
    * @return - the resource
    */
   public String getResource() {
     return resource;
   }
 
   /**
    * Setter for the resource (used by the SqlMapBuilder).
    *
    * @param resource
    *          - the resource name
    */
   public void setResource(String resource) {
     this.resource = resource;
   }
 
   /**
    * Adds the group by property.
    *
    * @param name
    *          the name
    */
   public void addGroupByProperty(String name) {
     if (groupByProps == null) {
       groupByProps = new HashSet();
     }
     groupByProps.add(name);
   }
 
   /**
    * Checks for group by.
    *
    * @return true, if successful
    */
   public boolean hasGroupBy() {
     return groupByProps != null && groupByProps.size() > 0;
   }
 
   /**
    * Group by props.
    *
    * @return the iterator
    */
   public Iterator groupByProps() {
     return groupByProps.iterator();
   }
 
   /**
    * Adds the nested result mappings.
    *
    * @param mapping
    *          the mapping
    */
   public void addNestedResultMappings(ResultMapping mapping) {
     if (nestedResultMappings == null) {
       nestedResultMappings = new ArrayList();
     }
     nestedResultMappings.add(mapping);
   }
 
   /**
    * Gets the nested result mappings.
    *
    * @return the nested result mappings
    */
   public List getNestedResultMappings() {
     return nestedResultMappings;
   }
 
   /**
    * Gets the result mappings.
    *
    * @return the result mappings
    */
   public ResultMapping[] getResultMappings() {
     if (allowRemapping) {
       return (ResultMapping[]) remappableResultMappings.get();
     } else {
       return resultMappings;
     }
   }
 
   /**
    * Sets the discriminator.
    *
    * @param discriminator
    *          the new discriminator
    */
   public void setDiscriminator(Discriminator discriminator) {
     if (this.discriminator != null) {
       throw new SqlMapException("A discriminator may only be set once per result map.");
     }
     this.discriminator = discriminator;
   }
 
   /**
    * Gets the discriminator.
    *
    * @return the discriminator
    */
   public Discriminator getDiscriminator() {
     return discriminator;
   }
 
   /**
    * Resolve sub map.
    *
    * @param statementScope
    *          the statement scope
    * @param rs
    *          the rs
    *
    * @return the result map
    *
    * @throws SQLException
    *           the SQL exception
    */
   public ResultMap resolveSubMap(StatementScope statementScope, ResultSet rs) throws SQLException {
     ResultMap subMap = this;
     if (discriminator != null) {
       ResultMapping mapping = (ResultMapping) discriminator.getResultMapping();
       Object value = getPrimitiveResultMappingValue(rs, mapping);
       if (value == null) {
         value = doNullMapping(value, mapping);
       }
       subMap = discriminator.getSubMap(String.valueOf(value));
       if (subMap == null) {
         subMap = this;
       } else if (subMap != this) {
         subMap = subMap.resolveSubMap(statementScope, rs);
       }
     }
     return subMap;
   }
 
   /**
    * Setter for a list of the individual ResultMapping objects.
    *
    * @param resultMappingList
    *          - the list
    */
   public void setResultMappingList(List resultMappingList) {
     if (allowRemapping) {
       this.remappableResultMappings
           .set((ResultMapping[]) resultMappingList.toArray(new ResultMapping[resultMappingList.size()]));
     } else {
       this.resultMappings = (ResultMapping[]) resultMappingList.toArray(new ResultMapping[resultMappingList.size()]);
     }
 
     Map props = new HashMap();
     props.put("map", this);
     dataExchange = getDelegate().getDataExchangeFactory().getDataExchangeForClass(resultClass);
     dataExchange.initialize(props);
   }
 
   /**
    * Getter for the number of ResultMapping objects.
    *
    * @return - the count
    */
   public int getResultCount() {
     return this.getResultMappings().length;
   }
 
   /**
    * Read a row from a resultset and map results to an array.
    *
    * @param statementScope
    *          scope of the request
    * @param rs
    *          ResultSet to read from
    *
    * @return row read as an array of column values.
    *
    * @throws SQLException
    *           the SQL exception
    */
   public Object[] getResults(StatementScope statementScope, ResultSet rs) throws SQLException {
     ErrorContext errorContext = statementScope.getErrorContext();
     errorContext.setActivity("applying a result map");
     errorContext.setObjectId(this.getId());
     errorContext.setResource(this.getResource());
     errorContext.setMoreInfo("Check the result map.");
 
     boolean foundData = false;
     Object[] columnValues = new Object[getResultMappings().length];
     for (int i = 0; i < getResultMappings().length; i++) {
       ResultMapping mapping = (ResultMapping) getResultMappings()[i];
       errorContext.setMoreInfo(mapping.getErrorString());
       if (mapping.getStatementName() != null) {
         if (resultClass == null) {
           throw new SqlMapException(
               "The result class was null when trying to get results for ResultMap named " + getId() + ".");
         } else if (Map.class.isAssignableFrom(resultClass)) {
           Class javaType = mapping.getJavaType();
           if (javaType == null) {
             javaType = Object.class;
           }
           columnValues[i] = getNestedSelectMappingValue(statementScope, rs, mapping, javaType);
         } else if (DomTypeMarker.class.isAssignableFrom(resultClass)) {
           Class javaType = mapping.getJavaType();
           if (javaType == null) {
             javaType = DomTypeMarker.class;
           }
           columnValues[i] = getNestedSelectMappingValue(statementScope, rs, mapping, javaType);
         } else {
           Probe p = ProbeFactory.getProbe(resultClass);
           Class type = p.getPropertyTypeForSetter(resultClass, mapping.getPropertyName());
           columnValues[i] = getNestedSelectMappingValue(statementScope, rs, mapping, type);
         }
         foundData = foundData || columnValues[i] != null;
       } else if (mapping.getNestedResultMapName() == null) {
         columnValues[i] = getPrimitiveResultMappingValue(rs, mapping);
         if (columnValues[i] == null) {
           columnValues[i] = doNullMapping(columnValues[i], mapping);
         } else {
           foundData = true;
         }
       }
     }
 
     statementScope.setRowDataFound(foundData);
 
     return columnValues;
   }
 
   /**
    * Sets the result object values.
    *
    * @param statementScope
    *          the statement scope
    * @param resultObject
    *          the result object
    * @param values
    *          the values
    *
    * @return the object
    */
   public Object setResultObjectValues(StatementScope statementScope, Object resultObject, Object[] values) {
     final String previousNestedKey = statementScope.getCurrentNestedKey();
     String ukey = (String) getUniqueKey(statementScope.getCurrentNestedKey(), values);
     Map uniqueKeys = statementScope.getUniqueKeys(this);
     statementScope.setCurrentNestedKey(ukey);
     if (uniqueKeys != null && uniqueKeys.containsKey(ukey)) {
       // Unique key is already known, so get the existing result object and process additional
       // results.
       resultObject = uniqueKeys.get(ukey);
       applyNestedResultMap(statementScope, resultObject, values);
       resultObject = NO_VALUE;
     } else if (ukey == null || uniqueKeys == null || !uniqueKeys.containsKey(ukey)) {
       // Unique key is NOT known, so create a new result object and then process additional
       // results.
       resultObject = dataExchange.setData(statementScope, this, resultObject, values);
       // Lazy init key set, only if we're grouped by something (i.e. ukey != null)
       if (ukey != null) {
         if (uniqueKeys == null) {
           uniqueKeys = new HashMap();
           statementScope.setUniqueKeys(this, uniqueKeys);
         }
         uniqueKeys.put(ukey, resultObject);
       }
       applyNestedResultMap(statementScope, resultObject, values);
     } else {
       // Otherwise, we don't care about these results.
       resultObject = NO_VALUE;
     }
 
     statementScope.setCurrentNestedKey(previousNestedKey);
     return resultObject;
   }
 
   /**
    * Apply nested result map.
    *
    * @param statementScope
    *          the statement scope
    * @param resultObject
    *          the result object
    * @param values
    *          the values
    */
   private void applyNestedResultMap(StatementScope statementScope, Object resultObject, Object[] values) {
     if (resultObject != null && resultObject != NO_VALUE) {
       if (nestedResultMappings != null) {
         for (int i = 0, n = nestedResultMappings.size(); i < n; i++) {
           ResultMapping resultMapping = (ResultMapping) nestedResultMappings.get(i);
           setNestedResultMappingValue(resultMapping, statementScope, resultObject, values);
         }
       }
     }
   }
 
   /**
    * Some changes in this method for IBATIS-225:
    * <ul>
    * <li>We no longer require the nested property to be a collection. This will allow reuses of resultMaps on 1:1
    * relationships</li>
    * <li>If the nested property is not a collection, then it will be created/replaced by the values generated from the
    * current row.</li>
    * </ul>
    *
    * @param mapping
    *          the mapping
    * @param statementScope
    *          the statement scope
    * @param resultObject
    *          the result object
    * @param values
    *          the values
    */
   protected void setNestedResultMappingValue(ResultMapping mapping, StatementScope statementScope, Object resultObject,
       Object[] values) {
     try {
 
       String resultMapName = mapping.getNestedResultMapName();
       ResultMap resultMap = getDelegate().getResultMap(resultMapName);
       // get the discriminated submap if it exists
       resultMap = resultMap.resolveSubMap(statementScope, statementScope.getResultSet());
 
       Class type = mapping.getJavaType();
       String propertyName = mapping.getPropertyName();
 
       Object obj = PROBE.getObject(resultObject, propertyName);
 
       if (obj == null) {
         if (type == null) {
           type = PROBE.getPropertyTypeForSetter(resultObject, propertyName);
         }
 
         try {
           // create the object if is it a Collection. If not a Collection
           // then we will just set the property to the object created
           // in processing the nested result map
           if (Collection.class.isAssignableFrom(type)) {
             obj = ResultObjectFactoryUtil.createObjectThroughFactory(type);
             PROBE.setObject(resultObject, propertyName, obj);
           }
         } catch (Exception e) {
           throw new SqlMapException(
               "Error instantiating collection property for mapping '" + mapping.getPropertyName() + "'.  Cause: " + e,
               e);
         }
       }
 
       // JIRA 375
       // "Provide a way for not creating items from nested ResultMaps when the items contain only null values"
       boolean subResultObjectAbsent = false;
       if (mapping.getNotNullColumn() != null) {
         if (statementScope.getResultSet().getObject(mapping.getNotNullColumn()) == null) {
           subResultObjectAbsent = true;
         }
       }
       if (!subResultObjectAbsent) {
         values = resultMap.getResults(statementScope, statementScope.getResultSet());
         if (statementScope.isRowDataFound()) {
           Object o = resultMap.setResultObjectValues(statementScope, null, values);
           if (o != NO_VALUE) {
             if (obj != null && obj instanceof Collection) {
               ((Collection) obj).add(o);
             } else {
               PROBE.setObject(resultObject, propertyName, o);
             }
           }
         }
       }
     } catch (SQLException e) {
       throw new SqlMapException(
           "Error getting nested result map values for '" + mapping.getPropertyName() + "'.  Cause: " + e, e);
     }
   }
 
   /**
    * Gets the nested select mapping value.
    *
    * @param statementScope
    *          the statement scope
    * @param rs
    *          the rs
    * @param mapping
    *          the mapping
    * @param targetType
    *          the target type
    *
    * @return the nested select mapping value
    *
    * @throws SQLException
    *           the SQL exception
    */
   protected Object getNestedSelectMappingValue(StatementScope statementScope, ResultSet rs, ResultMapping mapping,
       Class targetType) throws SQLException {
     try {
       TypeHandlerFactory typeHandlerFactory = getDelegate().getTypeHandlerFactory();
 
       String statementName = mapping.getStatementName();
       SqlMapClientImpl client = (SqlMapClientImpl) statementScope.getSession().getSqlMapClient();
 
       MappedStatement mappedStatement = client.getMappedStatement(statementName);
       Class parameterType = mappedStatement.getParameterClass();
       Object parameterObject = null;
 
       if (parameterType == null) {
         parameterObject = prepareBeanParameterObject(statementScope, rs, mapping, parameterType);
       } else {
         if (typeHandlerFactory.hasTypeHandler(parameterType)) {
           parameterObject = preparePrimitiveParameterObject(rs, mapping, parameterType);
         } else if (DomTypeMarker.class.isAssignableFrom(parameterType)) {
           parameterObject = prepareDomParameterObject(rs, mapping);
         } else {
           parameterObject = prepareBeanParameterObject(statementScope, rs, mapping, parameterType);
         }
       }
 
       Object result = null;
       if (parameterObject != null) {
 
         Sql sql = mappedStatement.getSql();
         ResultMap resultMap = sql.getResultMap(statementScope, parameterObject);
         Class resultClass = resultMap.getResultClass();
 
         if (resultClass != null && !DomTypeMarker.class.isAssignableFrom(targetType)) {
           if (DomCollectionTypeMarker.class.isAssignableFrom(resultClass)) {
             targetType = DomCollectionTypeMarker.class;
           } else if (DomTypeMarker.class.isAssignableFrom(resultClass)) {
             targetType = DomTypeMarker.class;
           }
         }
 
         result = ResultLoader.loadResult(client, statementName, parameterObject, targetType);
 
         String nullValue = mapping.getNullValue();
         if (result == null && nullValue != null) {
           TypeHandler typeHandler = typeHandlerFactory.getTypeHandler(targetType);
           if (typeHandler != null) {
             result = typeHandler.valueOf(nullValue);
           }
         }
       }
       return result;
     } catch (InstantiationException e) {
       throw new NestedSQLException("Error setting nested bean property.  Cause: " + e, e);
     } catch (IllegalAccessException e) {
       throw new NestedSQLException("Error setting nested bean property.  Cause: " + e, e);
     }
 
   }
 
   /**
    * Prepare primitive parameter object.
    *
    * @param rs
    *          the rs
    * @param mapping
    *          the mapping
    * @param parameterType
    *          the parameter type
    *
    * @return the object
    *
    * @throws SQLException
    *           the SQL exception
    */
   private Object preparePrimitiveParameterObject(ResultSet rs, ResultMapping mapping, Class parameterType)
       throws SQLException {
     Object parameterObject;
     TypeHandlerFactory typeHandlerFactory = getDelegate().getTypeHandlerFactory();
     TypeHandler th = typeHandlerFactory.getTypeHandler(parameterType);
     parameterObject = th.getResult(rs, mapping.getColumnName());
     return parameterObject;
   }
 
   /**
    * New document.
    *
    * @param root
    *          the root
    *
    * @return the document
    */
   private Document newDocument(String root) {
     try {
       Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();
       doc.appendChild(doc.createElement(root));
       return doc;
     } catch (ParserConfigurationException e) {
       throw new RuntimeException("Error creating XML document.  Cause: " + e);
     }
   }
 
   /**
    * Prepare dom parameter object.
    *
    * @param rs
    *          the rs
    * @param mapping
    *          the mapping
    *
    * @return the object
    *
    * @throws SQLException
    *           the SQL exception
    */
   private Object prepareDomParameterObject(ResultSet rs, ResultMapping mapping) throws SQLException {
     TypeHandlerFactory typeHandlerFactory = getDelegate().getTypeHandlerFactory();
 
     Document doc = newDocument("parameter");
     Probe probe = ProbeFactory.getProbe(doc);
 
     String complexName = mapping.getColumnName();
 
     TypeHandler stringTypeHandler = typeHandlerFactory.getTypeHandler(String.class);
     if (complexName.indexOf('=') > -1) {
       // old 1.x style multiple params
       StringTokenizer parser = new StringTokenizer(complexName, "{}=, ", false);
       while (parser.hasMoreTokens()) {
         String propName = parser.nextToken();
         String colName = parser.nextToken();
         Object propValue = stringTypeHandler.getResult(rs, colName);
         probe.setObject(doc, propName, propValue.toString());
       }
     } else {
       // single param
       Object propValue = stringTypeHandler.getResult(rs, complexName);
       probe.setObject(doc, "value", propValue.toString());
     }
 
     return doc;
   }
 
   /**
    * Prepare bean parameter object.
    *
    * @param statementScope
    *          the statement scope
    * @param rs
    *          the rs
    * @param mapping
    *          the mapping
    * @param parameterType
    *          the parameter type
    *
    * @return the object
    *
    * @throws InstantiationException
    *           the instantiation exception
    * @throws IllegalAccessException
    *           the illegal access exception
    * @throws SQLException
    *           the SQL exception
    */
   private Object prepareBeanParameterObject(StatementScope statementScope, ResultSet rs, ResultMapping mapping,
       Class parameterType) throws InstantiationException, IllegalAccessException, SQLException {
     TypeHandlerFactory typeHandlerFactory = getDelegate().getTypeHandlerFactory();
 
     Object parameterObject;
     if (parameterType == null) {
       parameterObject = new HashMap();
     } else {
       parameterObject = ResultObjectFactoryUtil.createObjectThroughFactory(parameterType);
     }
     String complexName = mapping.getColumnName();
 
     if (complexName.indexOf('=') > -1 || complexName.indexOf(',') > -1) {
       StringTokenizer parser = new StringTokenizer(complexName, "{}=, ", false);
       while (parser.hasMoreTokens()) {
         String propName = parser.nextToken();
         String colName = parser.nextToken();
         Class propType = PROBE.getPropertyTypeForSetter(parameterObject, propName);
         TypeHandler propTypeHandler = typeHandlerFactory.getTypeHandler(propType);
         Object propValue = propTypeHandler.getResult(rs, colName);
         PROBE.setObject(parameterObject, propName, propValue);
       }
     } else {
       // single param
       TypeHandler propTypeHandler = typeHandlerFactory.getTypeHandler(parameterType);
       if (propTypeHandler == null) {
         propTypeHandler = typeHandlerFactory.getUnkownTypeHandler();
       }
       parameterObject = propTypeHandler.getResult(rs, complexName);
     }
 
     return parameterObject;
   }
 
   /**
    * Gets the primitive result mapping value.
    *
    * @param rs
    *          the rs
    * @param mapping
    *          the mapping
    *
    * @return the primitive result mapping value
    *
    * @throws SQLException
    *           the SQL exception
    */
   protected Object getPrimitiveResultMappingValue(ResultSet rs, ResultMapping mapping) throws SQLException {
     Object value = null;
     TypeHandler typeHandler = mapping.getTypeHandler();
     if (typeHandler != null) {
       String columnName = mapping.getColumnName();
       int columnIndex = mapping.getColumnIndex();
       if (columnName == null) {
         value = typeHandler.getResult(rs, columnIndex);
       } else {
         value = typeHandler.getResult(rs, columnName);
       }
     } else {
       throw new SqlMapException("No type handler could be found to map the property '" + mapping.getPropertyName()
           + "' to the column '" + mapping.getColumnName()
           + "'.  One or both of the types, or the combination of types is not supported.");
     }
     return value;
   }
 
   /**
    * Do null mapping.
    *
    * @param value
    *          the value
    * @param mapping
    *          the mapping
    *
    * @return the object
    *
    * @throws SqlMapException
    *           the sql map exception
    */
   protected Object doNullMapping(Object value, ResultMapping mapping) throws SqlMapException {
     if (value == null) {
       TypeHandler typeHandler = mapping.getTypeHandler();
       if (typeHandler != null) {
         String nullValue = mapping.getNullValue();
         if (nullValue != null)
           value = typeHandler.valueOf(nullValue);
         return value;
       } else {
         throw new SqlMapException("No type handler could be found to map the property '" + mapping.getPropertyName()
             + "' to the column '" + mapping.getColumnName()
             + "'.  One or both of the types, or the combination of types is not supported.");
       }
     } else {
       return value;
     }
   }
 }