private StatementprepareStatement(StatementHandler handler) throwsSQLException { Statementstmt;

Connectionconnection = transaction.getConnection(); stmt =handler.prepare(connection);

handler.parameterize(stmt); return stmt;

} [java] view plaincopy

publicParameterHandler newParameterHandler(MappedStatement mappedStatement, ObjectparameterObject, BoundSql boundSql) { ParameterHandler parameterHandler = new DefaultParameterHandler(mappedStatement,parameterObject,boundSql);

parameterHandler = (ParameterHandler) interceptorChain.pluginAll(parameterHandler); returnparameterHandler;

} [java] view plaincopy

publicvoidsetParameters(PreparedStatement ps) throwsSQLException { ErrorContext.instance().activity("settingparameters").object(mappedStatement.getParameterMap().getId());

List parameterMappings = boundSql.getParameterMappings(); if(parameterMappings != null) {

MetaObject metaObject = parameterObject == null ? null :configuration.newMetaObject(parameterObject); for (int i = 0; i< parameterMappings.size(); i++) {

ParameterMapping parameterMapping = parameterMappings.get(i); if(parameterMapping.getMode() != ParameterMode.OUT) {

Object value; String propertyName = parameterMapping.getProperty();

PropertyTokenizer prop = newPropertyTokenizer(propertyName); if (parameterObject == null) {

value = null; } elseif (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())){

value = parameterObject; } elseif (boundSql.hasAdditionalParameter(propertyName)){

value = boundSql.getAdditionalParameter(propertyName); } elseif(propertyName.startsWith(ForEachSqlNode.ITEM_PREFIX)

&& boundSql.hasAdditionalParameter(prop.getName())){ value = boundSql.getAdditionalParameter(prop.getName());

if (value != null) { value = configuration.newMetaObject(value).getValue(propertyName.substring(prop.getName().length()));

} } else {

value = metaObject == null ? null :metaObject.getValue(propertyName); }

TypeHandler typeHandler = parameterMapping.getTypeHandler(); if (typeHandler == null) {

thrownew ExecutorException("Therewas no TypeHandler found for parameter " + propertyName + " of statement " + mappedStatement.getId()); }

typeHandler.setParameter(ps, i + 1, value,parameterMapping.getJdbcType()); }

}

}

} [java] view plaincopy

publicResultSetHandler newResultSetHandler(Executor executor, MappedStatementmappedStatement, RowBoundsrowBounds, ParameterHandler parameterHandler, ResultHandler resultHandler, BoundSqlboundSql) {

ResultSetHandler resultSetHandler =mappedStatement.hasNestedResultMaps() ? newNestedResultSetHandler(executor, mappedStatement, parameterHandler,resultHandler, boundSql, rowBounds): new FastResultSetHandler(executor,mappedStatement, parameterHandler, resultHandler, boundSql, rowBounds); resultSetHandler = (ResultSetHandler) interceptorChain.pluginAll(resultSetHandler);

returnresultSetHandler; } [java] view plaincopy

ResultSetHandler内部一条记录一条记录的处理，在处理每条记录的每一列时会调用TypeHandler转换结果，如下：

protectedbooleanapplyAutomaticMappings(ResultSet rs, List unmappedColumnNames,MetaObject metaObject) throws SQLException { booleanfoundValues = false;