org.apache.ibatis.mapping.ResultMapping Java Examples

private String processNestedResultMappings(XNode context, List<ResultMapping> resultMappings) throws Exception {
	  //处理association|collection|case
    if ("association".equals(context.getName())
        || "collection".equals(context.getName())
        || "case".equals(context.getName())) {
    	
//    	<resultMap id="blogResult" type="Blog">
//    	  <association property="author" column="author_id" javaType="Author" select="selectAuthor"/>
//    	</resultMap>
//如果不是嵌套查询
      if (context.getStringAttribute("select") == null) {
    	//则递归调用5.1 resultMapElement
        ResultMap resultMap = resultMapElement(context, resultMappings);
        return resultMap.getId();
      }
    }
    return null;
  }
 

private void createRowKeyForMappedProperties(ResultMap resultMap, ResultSetWrapper rsw, CacheKey cacheKey, List<ResultMapping> resultMappings, String columnPrefix) throws SQLException {
  for (ResultMapping resultMapping : resultMappings) {
    if (resultMapping.getNestedResultMapId() != null && resultMapping.getResultSet() == null) {
      // Issue #392
      final ResultMap nestedResultMap = configuration.getResultMap(resultMapping.getNestedResultMapId());
      createRowKeyForMappedProperties(nestedResultMap, rsw, cacheKey, nestedResultMap.getConstructorResultMappings(),
          prependPrefix(resultMapping.getColumnPrefix(), columnPrefix));
    } else if (resultMapping.getNestedQueryId() == null) {
      final String column = prependPrefix(resultMapping.getColumn(), columnPrefix);
      final TypeHandler<?> th = resultMapping.getTypeHandler();
      List<String> mappedColumnNames = rsw.getMappedColumnNames(resultMap, columnPrefix);
      // Issue #114
      if (column != null && mappedColumnNames.contains(column.toUpperCase(Locale.ENGLISH))) {
        final Object value = th.getResult(rsw.getResultSet(), column);
        if (value != null) {
          cacheKey.update(column);
          cacheKey.update(value);
        }
      }
    }
  }
}
 

private Discriminator processDiscriminatorElement(XNode context, Class<?> resultType, List<ResultMapping> resultMappings) throws Exception {
  String column = context.getStringAttribute("column");
  String javaType = context.getStringAttribute("javaType");
  String jdbcType = context.getStringAttribute("jdbcType");
  String typeHandler = context.getStringAttribute("typeHandler");
  Class<?> javaTypeClass = resolveClass(javaType);
  @SuppressWarnings("unchecked")
  Class<? extends TypeHandler<?>> typeHandlerClass = (Class<? extends TypeHandler<?>>) resolveClass(typeHandler);
  JdbcType jdbcTypeEnum = resolveJdbcType(jdbcType);
  Map<String, String> discriminatorMap = new HashMap<String, String>();
  for (XNode caseChild : context.getChildren()) {
    String value = caseChild.getStringAttribute("value");
    String resultMap = caseChild.getStringAttribute("resultMap", processNestedResultMappings(caseChild, resultMappings));
    discriminatorMap.put(value, resultMap);
  }
  return builderAssistant.buildDiscriminator(resultType, column, javaTypeClass, jdbcTypeEnum, typeHandlerClass, discriminatorMap);
}
 

private ResultMapping buildResultMappingFromContext(XNode context, Class<?> resultType, List<ResultFlag> flags) throws Exception {
//<id property="id" column="author_id"/>
//<result property="username" column="author_username"/>
   String property = context.getStringAttribute("property");
   String column = context.getStringAttribute("column");
   String javaType = context.getStringAttribute("javaType");
   String jdbcType = context.getStringAttribute("jdbcType");
   String nestedSelect = context.getStringAttribute("select");
   //处理嵌套的result map
   String nestedResultMap = context.getStringAttribute("resultMap",
       processNestedResultMappings(context, Collections.<ResultMapping> emptyList()));
   String notNullColumn = context.getStringAttribute("notNullColumn");
   String columnPrefix = context.getStringAttribute("columnPrefix");
   String typeHandler = context.getStringAttribute("typeHandler");
   String resulSet = context.getStringAttribute("resultSet");
   String foreignColumn = context.getStringAttribute("foreignColumn");
   boolean lazy = "lazy".equals(context.getStringAttribute("fetchType", configuration.isLazyLoadingEnabled() ? "lazy" : "eager"));
   Class<?> javaTypeClass = resolveClass(javaType);
   @SuppressWarnings("unchecked")
   Class<? extends TypeHandler<?>> typeHandlerClass = (Class<? extends TypeHandler<?>>) resolveClass(typeHandler);
   JdbcType jdbcTypeEnum = resolveJdbcType(jdbcType);
   //又去调builderAssistant.buildResultMapping
   return builderAssistant.buildResultMapping(resultType, property, column, javaTypeClass, jdbcTypeEnum, nestedSelect, nestedResultMap, notNullColumn, columnPrefix, typeHandlerClass, flags, resulSet, foreignColumn, lazy);
 }
 

private Object createResultObject(ResultSetWrapper rsw, ResultMap resultMap, ResultLoaderMap lazyLoader, String columnPrefix) throws SQLException {
  final List<Class<?>> constructorArgTypes = new ArrayList<Class<?>>();
  final List<Object> constructorArgs = new ArrayList<Object>();
  final Object resultObject = createResultObject(rsw, resultMap, constructorArgTypes, constructorArgs, columnPrefix);
  if (resultObject != null && !typeHandlerRegistry.hasTypeHandler(resultMap.getType())) {
    final List<ResultMapping> propertyMappings = resultMap.getPropertyResultMappings();
    for (ResultMapping propertyMapping : propertyMappings) {
      // issue gcode #109 && issue #149
      if (propertyMapping.getNestedQueryId() != null && propertyMapping.isLazy()) {
        //TODO 使用代理(cglib/javaassist)
        return configuration.getProxyFactory().createProxy(resultObject, lazyLoader, configuration, objectFactory, constructorArgTypes, constructorArgs);
      }
    }
  }
  return resultObject;
}
 

private void handleRowValuesForNestedResultMap(ResultSetWrapper rsw, ResultMap resultMap, ResultHandler resultHandler, RowBounds rowBounds, ResultMapping parentMapping) throws SQLException {
  final DefaultResultContext resultContext = new DefaultResultContext();
  skipRows(rsw.getResultSet(), rowBounds);
  Object rowValue = null;
  while (shouldProcessMoreRows(resultContext, rowBounds) && rsw.getResultSet().next()) {
    final ResultMap discriminatedResultMap = resolveDiscriminatedResultMap(rsw.getResultSet(), resultMap, null);
    final CacheKey rowKey = createRowKey(discriminatedResultMap, rsw, null);
    Object partialObject = nestedResultObjects.get(rowKey);
    // issue #577 && #542
    if (mappedStatement.isResultOrdered()) {
      if (partialObject == null && rowValue != null) {
        nestedResultObjects.clear();
        storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
      }
      rowValue = getRowValue(rsw, discriminatedResultMap, rowKey, rowKey, null, partialObject);
    } else {
      rowValue = getRowValue(rsw, discriminatedResultMap, rowKey, rowKey, null, partialObject);
      if (partialObject == null) {
        storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
      }
    }
  }
  if (rowValue != null && mappedStatement.isResultOrdered() && shouldProcessMoreRows(resultContext, rowBounds)) {
    storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
  }
}
 

private void applyConstructorArgs(Arg[] args, Class<?> resultType, List<ResultMapping> resultMappings) {
  for (Arg arg : args) {
    List<ResultFlag> flags = new ArrayList<ResultFlag>();
    flags.add(ResultFlag.CONSTRUCTOR);
    if (arg.id()) {
      flags.add(ResultFlag.ID);
    }
    ResultMapping resultMapping = assistant.buildResultMapping(
        resultType,
        null,
        nullOrEmpty(arg.column()),
        arg.javaType() == void.class ? null : arg.javaType(),
        arg.jdbcType() == JdbcType.UNDEFINED ? null : arg.jdbcType(),
        nullOrEmpty(arg.select()),
        nullOrEmpty(arg.resultMap()),
        null,
        null,
        arg.typeHandler() == UnknownTypeHandler.class ? null : arg.typeHandler(),
        flags,
        null,
        null,
        false);
    resultMappings.add(resultMapping);
  }
}
 

private Object createParameterizedResultObject(ResultSetWrapper rsw, Class<?> resultType, List<ResultMapping> constructorMappings,
    List<Class<?>> constructorArgTypes, List<Object> constructorArgs, String columnPrefix) throws SQLException {
  boolean foundValues = false;
  for (ResultMapping constructorMapping : constructorMappings) {
    final Class<?> parameterType = constructorMapping.getJavaType();
    final String column = constructorMapping.getColumn();
    final Object value;
    if (constructorMapping.getNestedQueryId() != null) {
      value = getNestedQueryConstructorValue(rsw.getResultSet(), constructorMapping, columnPrefix);
    } else if (constructorMapping.getNestedResultMapId() != null) {
      final ResultMap resultMap = configuration.getResultMap(constructorMapping.getNestedResultMapId());
      value = getRowValue(rsw, resultMap);
    } else {
      final TypeHandler<?> typeHandler = constructorMapping.getTypeHandler();
      value = typeHandler.getResult(rsw.getResultSet(), prependPrefix(column, columnPrefix));
    }
    constructorArgTypes.add(parameterType);
    constructorArgs.add(value);
    foundValues = value != null || foundValues;
  }
  return foundValues ? objectFactory.create(resultType, constructorArgTypes, constructorArgs) : null;
}
 

public static MappedStatement createSelectAuthorWithIDof99MappedStatement(final Configuration config) {
  final TypeHandlerRegistry registry = config.getTypeHandlerRegistry();
  MappedStatement ms = new MappedStatement.Builder(config, "selectAuthor", new StaticSqlSource(config,"SELECT * FROM author WHERE id = 99"), SqlCommandType.SELECT)
      .statementType(StatementType.STATEMENT)
      .parameterMap(new ParameterMap.Builder(config, "defaultParameterMap", Author.class, new ArrayList<ParameterMapping>()).build())
      .resultMaps(new ArrayList<ResultMap>() {
        {
          add(new ResultMap.Builder(config, "defaultResultMap", Author.class, new ArrayList<ResultMapping>() {
            {
              add(new ResultMapping.Builder(config, "id", "id", registry.getTypeHandler(int.class)).build());
              add(new ResultMapping.Builder(config, "username", "username", registry.getTypeHandler(String.class)).build());
              add(new ResultMapping.Builder(config, "password", "password", registry.getTypeHandler(String.class)).build());
              add(new ResultMapping.Builder(config, "email", "email", registry.getTypeHandler(String.class)).build());
              add(new ResultMapping.Builder(config, "bio", "bio", registry.getTypeHandler(String.class)).build());
            }
          }).build());
        }
      }).build();
  return ms;
}
 

private CacheKey createKeyForMultipleResults(ResultSet rs, ResultMapping resultMapping, String names, String columns) throws SQLException {
  CacheKey cacheKey = new CacheKey();
  cacheKey.update(resultMapping);
  if (columns != null && names != null) {
    String[] columnsArray = columns.split(",");
    String[] namesArray = names.split(",");
    for (int i = 0 ; i < columnsArray.length ; i++) {
      Object value = rs.getString(columnsArray[i]);
      if (value != null) {
        cacheKey.update(namesArray[i]);
        cacheKey.update(value);
      }
    }
  }
  return cacheKey;
}
 

/** Backward compatibility signature */
//向后兼容方法
public ResultMapping buildResultMapping(
    Class<?> resultType,
    String property,
    String column,
    Class<?> javaType,
    JdbcType jdbcType,
    String nestedSelect,
    String nestedResultMap,
    String notNullColumn,
    String columnPrefix,
    Class<? extends TypeHandler<?>> typeHandler,
    List<ResultFlag> flags) {
    return buildResultMapping(
      resultType, property, column, javaType, jdbcType, nestedSelect, 
      nestedResultMap, notNullColumn, columnPrefix, typeHandler, flags, null, null, configuration.isLazyLoadingEnabled());
}
 

private void handleRowValuesForNestedResultMap(ResultSetWrapper rsw, ResultMap resultMap, ResultHandler resultHandler, RowBounds rowBounds, ResultMapping parentMapping) throws SQLException {
  final DefaultResultContext resultContext = new DefaultResultContext();
  skipRows(rsw.getResultSet(), rowBounds);
  Object rowValue = null;
  while (shouldProcessMoreRows(resultContext, rowBounds) && rsw.getResultSet().next()) {
    final ResultMap discriminatedResultMap = resolveDiscriminatedResultMap(rsw.getResultSet(), resultMap, null);
    final CacheKey rowKey = createRowKey(discriminatedResultMap, rsw, null);
    Object partialObject = nestedResultObjects.get(rowKey);
    // issue #577 && #542
    if (mappedStatement.isResultOrdered()) {
      if (partialObject == null && rowValue != null) {
        nestedResultObjects.clear();
        storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
      }
      rowValue = getRowValue(rsw, discriminatedResultMap, rowKey, rowKey, null, partialObject);
    } else {
      rowValue = getRowValue(rsw, discriminatedResultMap, rowKey, rowKey, null, partialObject);
      if (partialObject == null) {
        storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
      }
    }
  }
  if (rowValue != null && mappedStatement.isResultOrdered() && shouldProcessMoreRows(resultContext, rowBounds)) {
    storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
  }
}
 

private Object instantiateCollectionPropertyIfAppropriate(ResultMapping resultMapping, MetaObject metaObject) {
  final String propertyName = resultMapping.getProperty();
  Object propertyValue = metaObject.getValue(propertyName);
  if (propertyValue == null) {
    Class<?> type = resultMapping.getJavaType();
    if (type == null) {
      type = metaObject.getSetterType(propertyName);
    }
    try {
      if (objectFactory.isCollection(type)) {
        propertyValue = objectFactory.create(type);
        metaObject.setValue(propertyName, propertyValue);
        return propertyValue;
      }
    } catch (Exception e) {
      throw new ExecutorException("Error instantiating collection property for result '" + resultMapping.getProperty() + "'.  Cause: " + e, e);
    }
  } else if (objectFactory.isCollection(propertyValue.getClass())) {
    return propertyValue;
  }
  return null;
}
 

private void linkToParents(ResultSet rs, ResultMapping parentMapping, Object rowValue) throws SQLException {
  CacheKey parentKey = createKeyForMultipleResults(rs, parentMapping, parentMapping.getColumn(), parentMapping.getForeignColumn());
  List<PendingRelation> parents = pendingRelations.get(parentKey);
  for (PendingRelation parent : parents) {
    if (parent != null) {
      final Object collectionProperty = instantiateCollectionPropertyIfAppropriate(parent.propertyMapping, parent.metaObject);
      if (rowValue != null) {
        if (collectionProperty != null) {
          final MetaObject targetMetaObject = configuration.newMetaObject(collectionProperty);
          targetMetaObject.add(rowValue);
        } else {
          parent.metaObject.setValue(parent.propertyMapping.getProperty(), rowValue);
        }
      }
    }
  }
}
 

private String processNestedResultMappings(XNode context, List<ResultMapping> resultMappings) throws Exception {
	  //处理association|collection|case
    if ("association".equals(context.getName())
        || "collection".equals(context.getName())
        || "case".equals(context.getName())) {
    	
//    	<resultMap id="blogResult" type="Blog">
//    	  <association property="author" column="author_id" javaType="Author" select="selectAuthor"/>
//    	</resultMap>
//如果不是嵌套查询
      if (context.getStringAttribute("select") == null) {
    	//则递归调用5.1 resultMapElement
        ResultMap resultMap = resultMapElement(context, resultMappings);
        return resultMap.getId();
      }
    }
    return null;
  }
 

private void linkToParents(ResultSet rs, ResultMapping parentMapping, Object rowValue) throws SQLException {
  CacheKey parentKey = createKeyForMultipleResults(rs, parentMapping, parentMapping.getColumn(), parentMapping.getForeignColumn());
  List<PendingRelation> parents = pendingRelations.get(parentKey);
  if (parents != null) {
    for (PendingRelation parent : parents) {
      if (parent != null) {
        final Object collectionProperty = instantiateCollectionPropertyIfAppropriate(parent.propertyMapping, parent.metaObject);
        if (rowValue != null) {
          if (collectionProperty != null) {
            final MetaObject targetMetaObject = configuration.newMetaObject(collectionProperty);
            targetMetaObject.add(rowValue);
          } else {
            parent.metaObject.setValue(parent.propertyMapping.getProperty(), rowValue);
          }
        }
      }
    }
  }
}
 

/** Backward compatibility signature */
//向后兼容方法
public ResultMapping buildResultMapping(
    Class<?> resultType,
    String property,
    String column,
    Class<?> javaType,
    JdbcType jdbcType,
    String nestedSelect,
    String nestedResultMap,
    String notNullColumn,
    String columnPrefix,
    Class<? extends TypeHandler<?>> typeHandler,
    List<ResultFlag> flags) {
    return buildResultMapping(
      resultType, property, column, javaType, jdbcType, nestedSelect, 
      nestedResultMap, notNullColumn, columnPrefix, typeHandler, flags, null, null, configuration.isLazyLoadingEnabled());
}
 

private Object createResultObject(ResultSetWrapper rsw, ResultMap resultMap, List<Class<?>> constructorArgTypes, List<Object> constructorArgs, String columnPrefix)
     throws SQLException {
//得到result type
   final Class<?> resultType = resultMap.getType();
   final MetaClass metaType = MetaClass.forClass(resultType);
   final List<ResultMapping> constructorMappings = resultMap.getConstructorResultMappings();
   if (typeHandlerRegistry.hasTypeHandler(resultType)) {
     //基本型
     return createPrimitiveResultObject(rsw, resultMap, columnPrefix);
   } else if (!constructorMappings.isEmpty()) {
     //有参数的构造函数
     return createParameterizedResultObject(rsw, resultType, constructorMappings, constructorArgTypes, constructorArgs, columnPrefix);
   } else if (resultType.isInterface() || metaType.hasDefaultConstructor()) {
     //普通bean类型
     return objectFactory.create(resultType);
   } else if (shouldApplyAutomaticMappings(resultMap, false)) {
     //自动映射
     return createByConstructorSignature(rsw, resultType, constructorArgTypes, constructorArgs, columnPrefix);
   }
   throw new ExecutorException("Do not know how to create an instance of " + resultType);
 }
 

private void applyResults(Result[] results, Class<?> resultType, List<ResultMapping> resultMappings) {
  for (Result result : results) {
    List<ResultFlag> flags = new ArrayList<ResultFlag>();
    if (result.id()) {
      flags.add(ResultFlag.ID);
    }
    ResultMapping resultMapping = assistant.buildResultMapping(
        resultType,
        nullOrEmpty(result.property()),
        nullOrEmpty(result.column()),
        result.javaType() == void.class ? null : result.javaType(),
        result.jdbcType() == JdbcType.UNDEFINED ? null : result.jdbcType(),
        hasNestedSelect(result) ? nestedSelectId(result) : null,
        null,
        null,
        null,
        result.typeHandler() == UnknownTypeHandler.class ? null : result.typeHandler(),
        flags,
        null,
        null,
        isLazy(result));
    resultMappings.add(resultMapping);
  }
}
 

private Object instantiateCollectionPropertyIfAppropriate(ResultMapping resultMapping, MetaObject metaObject) {
  final String propertyName = resultMapping.getProperty();
  Object propertyValue = metaObject.getValue(propertyName);
  if (propertyValue == null) {
    Class<?> type = resultMapping.getJavaType();
    if (type == null) {
      type = metaObject.getSetterType(propertyName);
    }
    try {
      if (objectFactory.isCollection(type)) {
        propertyValue = objectFactory.create(type);
        metaObject.setValue(propertyName, propertyValue);
        return propertyValue;
      }
    } catch (Exception e) {
      throw new ExecutorException("Error instantiating collection property for result '" + resultMapping.getProperty() + "'.  Cause: " + e, e);
    }
  } else if (objectFactory.isCollection(propertyValue.getClass())) {
    return propertyValue;
  }
  return null;
}
 

private Discriminator processDiscriminatorElement(XNode context, Class<?> resultType, List<ResultMapping> resultMappings) throws Exception {
  String column = context.getStringAttribute("column");
  String javaType = context.getStringAttribute("javaType");
  String jdbcType = context.getStringAttribute("jdbcType");
  String typeHandler = context.getStringAttribute("typeHandler");
  Class<?> javaTypeClass = resolveClass(javaType);
  @SuppressWarnings("unchecked")
  Class<? extends TypeHandler<?>> typeHandlerClass = (Class<? extends TypeHandler<?>>) resolveClass(typeHandler);
  JdbcType jdbcTypeEnum = resolveJdbcType(jdbcType);
  Map<String, String> discriminatorMap = new HashMap<String, String>();
  for (XNode caseChild : context.getChildren()) {
    String value = caseChild.getStringAttribute("value");
    String resultMap = caseChild.getStringAttribute("resultMap", processNestedResultMappings(caseChild, resultMappings));
    discriminatorMap.put(value, resultMap);
  }
  return builderAssistant.buildDiscriminator(resultType, column, javaTypeClass, jdbcTypeEnum, typeHandlerClass, discriminatorMap);
}
 

private CacheKey createKeyForMultipleResults(ResultSet rs, ResultMapping resultMapping, String names, String columns) throws SQLException {
  CacheKey cacheKey = new CacheKey();
  cacheKey.update(resultMapping);
  if (columns != null && names != null) {
    String[] columnsArray = columns.split(",");
    String[] namesArray = names.split(",");
    for (int i = 0 ; i < columnsArray.length ; i++) {
      Object value = rs.getString(columnsArray[i]);
      if (value != null) {
        cacheKey.update(namesArray[i]);
        cacheKey.update(value);
      }
    }
  }
  return cacheKey;
}
 

private Object createResultObject(ResultSetWrapper rsw, ResultMap resultMap, ResultLoaderMap lazyLoader, String columnPrefix) throws SQLException {
  final List<Class<?>> constructorArgTypes = new ArrayList<Class<?>>();
  final List<Object> constructorArgs = new ArrayList<Object>();
  final Object resultObject = createResultObject(rsw, resultMap, constructorArgTypes, constructorArgs, columnPrefix);
  if (resultObject != null && !typeHandlerRegistry.hasTypeHandler(resultMap.getType())) {
    final List<ResultMapping> propertyMappings = resultMap.getPropertyResultMappings();
    for (ResultMapping propertyMapping : propertyMappings) {
      // issue gcode #109 && issue #149
      if (propertyMapping.getNestedQueryId() != null && propertyMapping.isLazy()) {
        //TODO 使用代理(cglib/javaassist)
        return configuration.getProxyFactory().createProxy(resultObject, lazyLoader, configuration, objectFactory, constructorArgTypes, constructorArgs);
      }
    }
  }
  return resultObject;
}
 

private void addPendingChildRelation(ResultSet rs, MetaObject metaResultObject, ResultMapping parentMapping) throws SQLException {
  CacheKey cacheKey = createKeyForMultipleResults(rs, parentMapping, parentMapping.getColumn(), parentMapping.getColumn());
  PendingRelation deferLoad = new PendingRelation();
  deferLoad.metaObject = metaResultObject;
  deferLoad.propertyMapping = parentMapping;
  List<PendingRelation> relations = pendingRelations.get(cacheKey);
  // issue #255
  if (relations == null) {
    relations = new ArrayList<DefaultResultSetHandler.PendingRelation>();
    pendingRelations.put(cacheKey, relations);
  }
  relations.add(deferLoad);
  ResultMapping previous = nextResultMaps.get(parentMapping.getResultSet());
  if (previous == null) {
    nextResultMaps.put(parentMapping.getResultSet(), parentMapping);
  } else {
    if (!previous.equals(parentMapping)) {
      throw new ExecutorException("Two different properties are mapped to the same resultSet");
    }
  }
}
 

private CacheKey createRowKey(ResultMap resultMap, ResultSetWrapper rsw, String columnPrefix) throws SQLException {
  final CacheKey cacheKey = new CacheKey();
  cacheKey.update(resultMap.getId());
  List<ResultMapping> resultMappings = getResultMappingsForRowKey(resultMap);
  if (resultMappings.size() == 0) {
    if (Map.class.isAssignableFrom(resultMap.getType())) {
      createRowKeyForMap(rsw, cacheKey);
    } else {
      createRowKeyForUnmappedProperties(resultMap, rsw, cacheKey, columnPrefix);
    }
  } else {
    createRowKeyForMappedProperties(resultMap, rsw, cacheKey, resultMappings, columnPrefix);
  }
  return cacheKey;
}
 

private CacheKey createRowKey(ResultMap resultMap, ResultSetWrapper rsw, String columnPrefix) throws SQLException {
  final CacheKey cacheKey = new CacheKey();
  cacheKey.update(resultMap.getId());
  List<ResultMapping> resultMappings = getResultMappingsForRowKey(resultMap);
  if (resultMappings.size() == 0) {
    if (Map.class.isAssignableFrom(resultMap.getType())) {
      createRowKeyForMap(rsw, cacheKey);
    } else {
      createRowKeyForUnmappedProperties(resultMap, rsw, cacheKey, columnPrefix);
    }
  } else {
    createRowKeyForMappedProperties(resultMap, rsw, cacheKey, resultMappings, columnPrefix);
  }
  return cacheKey;
}
 

private void handleRowValues(ResultSetWrapper rsw, ResultMap resultMap, ResultHandler resultHandler, RowBounds rowBounds, ResultMapping parentMapping) throws SQLException {
  if (resultMap.hasNestedResultMaps()) {
    ensureNoRowBounds();
    checkResultHandler();
    handleRowValuesForNestedResultMap(rsw, resultMap, resultHandler, rowBounds, parentMapping);
  } else {
    handleRowValuesForSimpleResultMap(rsw, resultMap, resultHandler, rowBounds, parentMapping);
  }
}
 

private Object prepareParameterForNestedQuery(ResultSet rs, ResultMapping resultMapping, Class<?> parameterType, String columnPrefix) throws SQLException {
  if (resultMapping.isCompositeResult()) {
    return prepareCompositeKeyParameter(rs, resultMapping, parameterType, columnPrefix);
  } else {
    return prepareSimpleKeyParameter(rs, resultMapping, parameterType, columnPrefix);
  }
}
 

private Object getNestedQueryConstructorValue(ResultSet rs, ResultMapping constructorMapping, String columnPrefix) throws SQLException {
  final String nestedQueryId = constructorMapping.getNestedQueryId();
  final MappedStatement nestedQuery = configuration.getMappedStatement(nestedQueryId);
  final Class<?> nestedQueryParameterType = nestedQuery.getParameterMap().getType();
  final Object nestedQueryParameterObject = prepareParameterForNestedQuery(rs, constructorMapping, nestedQueryParameterType, columnPrefix);
  Object value = null;
  if (nestedQueryParameterObject != null) {
    final BoundSql nestedBoundSql = nestedQuery.getBoundSql(nestedQueryParameterObject);
    final CacheKey key = executor.createCacheKey(nestedQuery, nestedQueryParameterObject, RowBounds.DEFAULT, nestedBoundSql);
    final Class<?> targetType = constructorMapping.getJavaType();
    final ResultLoader resultLoader = new ResultLoader(configuration, executor, nestedQuery, nestedQueryParameterObject, targetType, key, nestedBoundSql);
    value = resultLoader.loadResult();
  }
  return value;
}
 

private Object createPrimitiveResultObject(ResultSetWrapper rsw, ResultMap resultMap, String columnPrefix) throws SQLException {
  final Class<?> resultType = resultMap.getType();
  final String columnName;
  if (!resultMap.getResultMappings().isEmpty()) {
    final List<ResultMapping> resultMappingList = resultMap.getResultMappings();
    final ResultMapping mapping = resultMappingList.get(0);
    columnName = prependPrefix(mapping.getColumn(), columnPrefix);
  } else {
    //因为只有1列，所以取得这一列的名字
    columnName = rsw.getColumnNames().get(0);
  }
  final TypeHandler<?> typeHandler = rsw.getTypeHandler(resultType, columnName);
  return typeHandler.getResult(rsw.getResultSet(), columnName);
}